LAM KIEU MONG (CH)
LOUIE DAYNA (CH)
HEYES JAMES (CH)
MARTIN ALAN (CH)
WOOD MARK (CH)
ZHANG WENXUAN (CH)
WO2020061367A1 | 2020-03-26 | |||
WO2019152557A1 | 2019-08-08 | |||
WO2019036008A1 | 2019-02-21 | |||
WO2016197132A1 | 2016-12-08 | |||
WO2016197133A1 | 2016-12-08 | |||
WO2013151665A2 | 2013-10-10 | |||
WO1993023569A1 | 1993-11-25 | |||
WO1994002595A1 | 1994-02-03 | |||
WO1992007065A1 | 1992-04-30 | |||
WO1993015187A1 | 1993-08-05 | |||
WO1991003162A1 | 1991-03-21 | |||
WO1994013688A1 | 1994-06-23 | |||
WO1996011266A2 | 1996-04-18 | |||
WO2002069369A2 | 2002-09-06 | |||
WO2001015726A2 | 2001-03-08 | |||
WO2018006052A1 | 2018-01-04 | |||
WO2015011633A1 | 2015-01-29 | |||
WO1996040964A2 | 1996-12-19 | |||
WO2005026372A1 | 2005-03-24 | |||
WO2000062813A2 | 2000-10-26 | |||
WO2007012191A1 | 2007-02-01 | |||
WO2005007196A2 | 2005-01-27 | |||
WO2005121348A1 | 2005-12-22 | |||
WO2005120152A2 | 2005-12-22 | |||
WO2004002453A1 | 2004-01-08 |
US20180273467A1 | 2018-09-27 | |||
US198162633051P | ||||
US20040142025A1 | 2004-07-22 | |||
US20070042031A1 | 2007-02-22 | |||
US5885613A | 1999-03-23 | |||
US8936942B2 | 2015-01-20 | |||
US20080088676W | 2008-12-31 | |||
US7404969B2 | 2008-07-29 | |||
US4376110A | 1983-03-08 | |||
US4452901A | 1984-06-05 | |||
US3817827A | 1974-06-18 | |||
US3850752A | 1974-11-26 | |||
US3901654A | 1975-08-26 | |||
US3935074A | 1976-01-27 | |||
US3984533A | 1976-10-05 | |||
US3996345A | 1976-12-07 | |||
US4034074A | 1977-07-05 | |||
US4098876A | 1978-07-04 | |||
US4683195A | 1987-07-28 | |||
US4683202A | 1987-07-28 | |||
US5998203A | 1999-12-07 | |||
GB2397818B | 2005-03-09 | |||
US20040192626A1 | 2004-09-30 | |||
US20050282188A1 | 2005-12-22 | |||
US20070135372A1 | 2007-06-14 | |||
US20050074771A1 | 2005-04-07 | |||
US20050043219A1 | 2005-02-24 | |||
US20050158727A1 | 2005-07-21 | |||
US20030130186A1 | 2003-07-10 | |||
US20040110296A1 | 2004-06-10 | |||
US20040249178A1 | 2004-12-09 | |||
US6753423B1 | 2004-06-22 | |||
US20050119470A1 | 2005-06-02 | |||
US20050107325A1 | 2005-05-19 | |||
US20050153337A1 | 2005-07-14 | |||
US20040167090A1 | 2004-08-26 | |||
US20050239739A1 | 2005-10-27 | |||
US6713069B1 | 2004-03-30 | |||
US20070135370A1 | 2007-06-14 | |||
US20070218122A1 | 2007-09-20 | |||
US20060281175A1 | 2006-12-14 | |||
US20050058982A1 | 2005-03-17 | |||
US20070149470A1 | 2007-06-28 | |||
US7348314B2 | 2008-03-25 | |||
USPP61162127P | ||||
US20060134189A1 | 2006-06-22 | |||
USPP61147235P | ||||
US80787207A | 2007-05-29 | |||
US20050107316A1 | 2005-05-19 | |||
US20070265438A1 | 2007-11-15 | |||
US34334208A | 2008-12-23 | |||
USPP61045251P | ||||
GB2396864A | 2004-07-07 | |||
US20040142895A1 | 2004-07-22 | |||
CA2456444A1 | 2003-08-28 | |||
US6174861B1 | 2001-01-16 | |||
US5639725A | 1997-06-17 | |||
US5739119A | 1998-04-14 | |||
US5759829A | 1998-06-02 | |||
US5801154A | 1998-09-01 | |||
US5789573A | 1998-08-04 | |||
US5718709A | 1998-02-17 | |||
US5610288A | 1997-03-11 | |||
US5747470A | 1998-05-05 | |||
US5591317A | 1997-01-07 | |||
US5783683A | 1998-07-21 | |||
EP0360257A2 | 1990-03-28 | |||
US5631359A | 1997-05-20 | |||
US4987071A | 1991-01-22 | |||
EP92110298A | 1992-06-17 | |||
US5334711A | 1994-08-02 | |||
US6406705B1 | 2002-06-18 | |||
US5753613A | 1998-05-19 | |||
US5785992A | 1998-07-28 | |||
US5705385A | 1998-01-06 | |||
US5976567A | 1999-11-02 | |||
US5981501A | 1999-11-09 | |||
US6110745A | 2000-08-29 | |||
US6320017B1 | 2001-11-20 | |||
US20030077829A1 | 2003-04-24 | |||
US20050008689A1 | 2005-01-13 | |||
US6774180B2 | 2004-08-10 | |||
US7053150B2 | 2006-05-30 | |||
US6586559B2 | 2003-07-01 | |||
US4737323A | 1988-04-12 | |||
US9744103A | ||||
US6586410B1 | 2003-07-01 | |||
US6534484B1 | 2003-03-18 | |||
US6852334B1 | 2005-02-08 | |||
US20020072121A1 | 2002-06-13 | |||
US9005654B2 | 2015-04-14 | |||
US5286634A | 1994-02-15 | |||
US3993754A | 1976-11-23 | |||
US4145410A | 1979-03-20 | |||
US4235871A | 1980-11-25 | |||
US4224179A | 1980-09-23 | |||
US4522803A | 1985-06-11 | |||
US4588578A | 1986-05-13 | |||
US5756353A | 1998-05-26 | |||
US5804212A | 1998-09-08 | |||
US5725871A | 1998-03-10 | |||
US5780045A | 1998-07-14 | |||
US5641515A | 1997-06-24 | |||
US5580579A | 1996-12-03 | |||
US5792451A | 1998-08-11 | |||
US5426039A | 1995-06-20 |
BYROM ET AL., AMBION TECHNOTES, vol. 10, no. 1, 2003, pages 4 - 6
KAWASAKI ET AL., NUCLEIC ACIDS RES., vol. 31, 2003, pages 981 - 987
KNIGHT ET AL., SCIENCE, vol. 293, 2001, pages 2269 - 2271
ROBERTSON ET AL., J. BIOL. CHEM., vol. 243, 1968, pages 82
TIJSSEN: "Overview of principles of hybridization and the strategy of nucleic acid assays", TECHNIQUES IN BIOCHEMISTRY AND MOLECULAR BIOLOGY-HYBRIDIZATION WITH NUCLEIC PROBES, 1993
ALTSCHUL ET AL., J. MOL. BIOL., vol. 216, 1990, pages 585 - 610
SMITHWATERMAN, ADV. APPL. MATH., vol. 2, 1981, pages 482
NEEDLEMANWUNSCH, J. MOL. BIOL., vol. 48, 1970, pages 443
PEARSONLIPMAN, PROC. NATL. ACAD. SCI. USA, vol. 85, 1988, pages 2444
MESMAEKER ET AL.: "Carbohydrate Modifications in Antisense Research", 1994, ACS, article "Novel Backbone Replacements for Oligonucleotides", pages: 24 - 39
ALTSCHUL ET AL., NUC. ACIDS RES., vol. 25, 1977, pages 3389 - 3402
KARLINALTSCHUL, PROC. NATL. ACAD. SCI. USA, vol. 90, 1993, pages 5873 - 5787
BATZER ET AL., NUCLEIC ACID RES., vol. 19, 1991, pages 5081
OHTSUKA ET AL., J. BIOL. CHEM., vol. 260, 1985, pages 2605 - 2608
ROSSOLINI ET AL., MOL. CELL. PROBES, vol. 8, 1994, pages 91 - 98
HEYES ET AL.: "Synthesis and Characterization of Novel Poly (Ethylene Glycol)-lipid Conjugates Suitable for use in Drug Delivery", JOURNAL OF CONTROLLED RELEASE, 2006
ELBASHIR ET AL., GENES DEV., vol. 15, 2001, pages 188
NYKANEN ET AL., CELL, vol. 107, 2001, pages 309
BERNSTEIN ET AL., NATURE, vol. 409, 2001, pages 363 - 366
ELBASHIR ET AL., EMBO J., vol. 20, 2001, pages 6877 - 6888
REYNOLDS ET AL., NATURE BIOTECH., vol. 22, no. 3, 2004, pages 326 - 330
KHVOROVA ET AL., CELL, vol. 115, 2003, pages 199 - 208
LUO ET AL., BIOPHYS. RES. COMMUN., vol. 318, 2004, pages 303 - 310
WIDE ET AL.: "Radioimmunoassay Methods", 1970, E. AND S. LIVINGSTONE
BROWN ET AL., J. BIOL. CHEM., vol. 255, 1980, pages 4980 - 4983
RAINES ET AL., J. BIOL. CHEM., vol. 257, 1982, pages 5154 - 5160
BROOKS ET AL., CLIN. EXP. IMMUNOL., vol. 39, 1980, pages 477
BOWEN-POPE ET AL., PROC. NATL. ACAD. SCI. USA, vol. 81, 1984, pages 2396 - 2400
JUDGE ET AL., MOL. THER., vol. 13, 2006, pages 494 - 505
KOHLER ET AL., NATURE, vol. 256, 1975, pages 495 - 497
DECAUSSIN ET AL., J. PATHOL., vol. 188, 1999, pages 369 - 377
BUHRING ET AL., HYBRIDOMA, vol. 10, no. 1, 1991, pages 77 - 78
GUBLERHOFFMAN, GENE, vol. 25, 1983, pages 263 - 269
SCARINGE ET AL., NUCL. ACIDS RES., vol. 18, 1990, pages 5433
VASANTHAKUMAR ET AL., CANCER COMMUN., vol. 1, 1989, pages 225 - 32
USMAN ET AL., J. AM. CHEM. SOC., vol. 109, 1987, pages 7845
WINCOTT ET AL., NUCL. ACIDS RES., vol. 23, 1995, pages 2677 - 2684
WINCOTT ET AL., METHODS MOL. BIO., vol. 74, 1997, pages 59
NEEDHAM VANDEVANTER ET AL., NUCLEIC ACIDS RES., vol. 12, 1984, pages 6159
LIN ET AL., J. AM. CHEM. SOC., vol. 120, 1998, pages 8531 - 8532
LOAKES, NUCL. ACIDS RES., vol. 29, 2001, pages 2437 - 2447
BEAUCAGE ET AL., TETRAHEDRON, vol. 49, 1993, pages 1925
HUNZIKER ET AL.: "Modern Synthetic Methods", 1995, VCH, article "Nucleic Acid Analogues: Synthesis and Properties", pages: 331 - 417
GEISBERT ET AL., J. INFECT. DIS., vol. 193, 2006, pages 1650 - 1657
BUCHMEIER ET AL.: "FIELDS VIROLOGY", 2001, LIPPINCOTT-RAVEN, article "Arenaviridae: the viruses and their replication"
STEINHAUER ET AL., ANNU REV GENET., vol. 36, 2002, pages 305 - 332
NEUMANN ET AL., J GEN VIROL., vol. 83, 2002, pages 2635 - 2662
HAMASAKI ET AL., FEBS LETT., vol. 545, 2003, pages 144
YOKOTA ET AL., EMBO REP., vol. 4, 2003, pages 602
SCHLOMAI ET AL., HEPATOLOGY, vol. 37, 2003, pages 764
KAPADIA ET AL., PROC. NATL. ACAD. SCI. USA, vol. 100, 2003, pages 2014
BANERJEA ET AL., MOL. THER., vol. 8, 2003, pages 62
HALL ET AL., J. VIROL., vol. 77, 2003, pages 6066
STEPHENSON, JAMA, vol. 289, 2003, pages 1494
WILDA ET AL., ONCOGENE, vol. 21, 2002, pages 5716
"Genbank", Database accession no. NM-001042599
SANCHEZ ET AL., VIRUS RES., vol. 29, 1993, pages 215 - 240
WILL ET AL., J. VIROL., vol. 67, 1993, pages 1203 - 1210
VOLCHKOV ET AL., FEBS LETT., vol. 305, 1992, pages 181 - 184
"Genback", Database accession no. NM-007121
FORMAN ET AL., CELL, vol. 81, 1995, pages 687
SEOL ET AL., MOL. ENDOCRINOL., vol. 9, 1995, pages 72
ZAVACKI ET AL., PROC. NATL. ACAD. SCI. USA, vol. 94, 1997, pages 7909
SAKAI ET AL., CELL, vol. 85, 1996, pages 1037 - 1046
LEHMANN ET AL., J. BIOL. CHEM., vol. 272, 1997, pages 12778 - 12785
WILLY ET AL., GENES DEV., vol. 9, 1995, pages 1033 - 1045
JANOWSKI ET AL., NATURE, vol. 383, 1996, pages 728 - 731
PEET ET AL., CELL, vol. 93, 1998, pages 693 - 704
BARR ET AL., NAT. REV. MOL. CELL. BIOL., vol. 5, 2004, pages 429 - 440
HEIDENREICH ET AL., BLOOD, vol. 101, 2003, pages 3157
COLLIS ET AL., CANCER RES., vol. 63, 2003, pages 1550
ZOU ET AL., GENES DEV., vol. 16, 2002, pages 2923
VERMA ET AL., CLIN CANCER RES., vol. 9, 2003, pages 1291
KOSCIOLEK ET AL., MOL CANCER THER., vol. 2, 2003, pages 209
NAGY ET AL., EXP. CELL RES., vol. 285, 2003, pages 39 - 49
TUSCHLBORKHARDT, MOL. INTERVENTIONS, vol. 2, 2002, pages 158
REICH ET AL., MOL. VIS., vol. 9, 2003, pages 210
HILL ET AL., J. IMMUNOL., vol. 171, 2003, pages 691
SONG ET AL., NAT. MED., vol. 9, 2003, pages 347
HEINONEN ET AL., FEBS LETT., vol. 527, 2002, pages 274
CAPLEN ET AL., HUM. MOL. GENET., vol. 11, 2002, pages 175
SANDER ET AL., NATURE BIOTECHNOLOGY, vol. 32, no. 4, pages 347 - 355
SUN ET AL., NAT. BIOTECH., vol. 26, 2008, pages 1379 - 1382
LAGOS-QUINTANA ET AL., SCIENCE, vol. 241, 1988, pages 1077 - 864
DENLI ET AL., NATURE, vol. 432, 2004, pages 231 - 235
PREALL ET AL., CURR. BIOL., vol. 16, 2006, pages 530 - 535
GREGORY ET AL., CELL, vol. 123, 2005, pages 631 - 640
PENIS ET AL., BRAIN RES MOL BRAIN RES., vol. 15, no. 57, 1998, pages 310 - 20
ALTSCHUL ET AL., NUCLEIC ACIDS RES., vol. 25, 1997, pages 3389 - 402
KIM ET AL., PROC. NATL. ACAD. SCI. USA., vol. 84, 1987, pages 8788 - 92
FORSTER ET AL., CELL, vol. 49, 1987, pages 211 - 20
CECH ET AL., CELL, vol. 27, 1981, pages 487 - 96
REINHOLD-HUREK ET AL., NATURE, vol. 357, 1992, pages 173 - 6
ROSSI ET AL., NUCLEIC ACIDS RES., vol. 20, 1992, pages 4559 - 65
HAMPEL ET AL., BIOCHEMISTRY, vol. 28, 1989, pages 4929 - 33
HAMPEL ET AL., NUCLEIC ACIDS RES., vol. 18, 1990, pages 299 - 304
PERROTTA ET AL., BIOCHEMISTRY, vol. 31, 1992, pages 11843 - 52
GUERRIER-TAKADA ET AL., CELL, vol. 35, 1983, pages 849 - 57
SAVILLE ET AL., CELL, vol. 61, 1990, pages 685 - 96
SAVILLE ET AL., PROC. NATL. ACAD. SCI. USA, vol. 88, 1991, pages 8826 - 30
COLLINS ET AL., BIOCHEMISTRY, vol. 32, 1993, pages 2795 - 9
YAMAMOTO ET AL., J. IMMUNOL., vol. 148, 1992, pages 4072 - 6
RANEY ET AL., J. PHARM. EXPER. THER., vol. 298, 2001, pages 1185 - 92
MARCH: "ADVANCED ORGANIC CHEMISTRY", 1992, WILEY
NICOLAU ET AL., CRIT. REV. THER. DRUG CARRIER SYST., vol. 6, 1989, pages 239
THE JOURNAL OF NIH RESEARCH, vol. 3, 1991, pages 81
"Nucleic Acid Hybridization, A Practical Approach", 1985, MACK PUBLISHING COMPANY
STRAUBRINGER ET AL., METHODS ENZYMOL., vol. 101, 1983, pages 512
MANNINO ET AL., BIOTECHNIQUES, vol. 6, 1988, pages 682
BEHR, ACC. CHEM. RES., vol. 26, 1993, pages 274
FRESHNEY: "Culture of Animal Cells, a Manual of Basic Technique", 1994, MARYANN LIEBERT, INC., PUBLISHERS, pages: 70 - 71
BRIGHAM ET AL., AM. J. SCI., vol. 298, 1989, pages 278
KUCHLER ET AL.: "Biochemical Methods in Cell Culture and Virology", 1977, DOWDEN, HUTCHINSON AND ROSS, INC.
SAMBROOK ET AL.: "Molecular Cloning: A Laboratory Manual", 2000, COLD SPRING HARBOR LABORATORY PRESS
AUSUBEL ET AL.: "Current Protocols", 2002, GREENE PUBLISHING ASSOCIATES, INC., article "SHORT PROTOCOLS IN MOLECULAR BIOLOGY"
GUATELLI ET AL., PROC. NATL. ACAD. SCI. USA, vol. 87, 1990, pages 1874
ARNHEIMLEVINSON, C&EN, 1 October 1990 (1990-10-01), pages 36
KWOH ET AL., PROC. NATL. ACAD. SCI. USA, vol. 86, 1989, pages 1173
LOMELL ET AL., J. CLIN. CHEM., vol. 35, 1989, pages 1826
VAN BRUNT, BIOTECHNOLOGY, vol. 8, 1990, pages 291
WUWALLACE, GENE, vol. 4, 1989, pages 560
BARRINGER ET AL., GENE, vol. 89, 1990, pages 117
SOOKNANANMALEK, BIOTECHNOLOGY, vol. 13, 1995, pages 563
BEAUCAGE ET AL., TETRAHEDRON LETTS., vol. 22, 1981, pages 1859 - 1862
PEARSON ET AL., J. CHROM., vol. 255, 1983, pages 137 - 149
MAXAMGILBERT: "Methods in Enzymology", vol. 65, 1980, ACADEMIC PRESS, pages: 499
ANGERER ET AL., METHODS ENZYMOL., vol. 152, 1987, pages 649
CLAIMS WHAT IS CLAIMED IS: 1. A compound of formula (I): or a salt thereof, wherein: X is -CH2-, -O-, -O(C=O); or -C(=O)- Y is absent, -CH2-, -O-, -SO2-, or -C(=O)-; R1 is C2-C25hydrocarbyl; R2 is C1-C3alkyl; and R3 is C1-C3alkyl; or R2 and R3 taken together with the nitrogen to which they are attached form a a aziridino, azetidino, or pyrrolidino ring; m is 0, 1, 2, 3, 4, 5 or 6; n is 0-15; o is 0-15; L1 is absent, -(C=O)-O-, -(C=O)N(H)N(R4)-, -(C=O)N(H)- N=C(R4)-, -(C=O)N(H)N(H)C(R4)(R5)-, -(C=O)-O-CH2-Rz, or -O(C=O)-Rw-; L2 is absent, -(C=O)-O-, -(C=O)N(H)N(R4’)-, -(C=O)N(H)- N=C(R4’)-, -(C=O)N(H)N(H)C(R4’)(R5’)-, -(C=O)-O-CH2-Rz’, or -O(C=O)-Rx- a is H or F; b is H or F; c is H or F; and d is H or F; or c and d taken together with the carbon to which they are attached form -C(=O)-; R4 is H or C2-C25hydrocarbyl; R5 is H or C2-C25hydrocarbyl; R4’ is H or C2-C25hydrocarbyl; R5’ is H or C2-C25hydrocarbyl; R6 is C2-C25hydrocarbyl; R7 is C2-C25hydrocarbyl; Rw is absent, -C(F)H-, or -C(F)2-; Rx is absent, -C(F)H-, or -C(F)2-; Rz is phenyl that is substituted with 1, 2, or 3 groups independently selected from C2- C10hydrocarbyl; and Rz’ is phenyl that is substituted with 1, 2, or 3 groups independently selected from C2- C10hydrocarbyl. 2. The compound or salt of claim 1, wherein X is -CH2-. 3. The compound or salt of claim 1, wherein X is -C(=O)-. 4. The compound or salt of claim 1, wherein X is -O-. 5. The compound or salt of any one of claims 1-4, wherein R2 is methyl. 6. The compound or salt of any one of claims 1-4, wherein R2 is ethyl. 7. The compound or salt of any one of claims 1-4, wherein R2 is propyl. 8. The compound or salt of any one of claims 1-7, wherein R3 is methyl. 9. The compound or salt of any one of claims 1-7, wherein R3 is ethyl. 10. The compound or salt of any one of claims 1-7, wherein R3 is propyl. 11. The compound or salt of any one of claims 1-10, wherein m is 1. 12. The compound or salt of any one of claims 1-10, wherein m is 2. 13. The compound or salt of any one of claims 1-10, wherein m is 3. 14. The compound of claim 1, wherein: is selected from the group consisting of: (CH3)2NCH2CH2C(=O)-, (CH3)2NCH2CH2CH2C(=O)-, (CH3)2NCH2CH2CH2CH2C(=O)-, (CH3)2NCH2CH2-, (CH3)2NCH2CH2CH-, 5-pyrolidin-1-ylpentanoyl, and (CH3)2NCH2CH2CH2O-. 15. The compound or salt of any one of claims 1-14, wherein R1 is C5-C25hydrocarbyl. 16. The compound or salt of any one of claims 1-14, wherein R1 is C2-C25alkyl. 17. The compound or salt of any one of claims 1-14, wherein R1 is C5-C25alkyl. 18. The compound or salt of any one of claims 1-14, wherein R1 is C5-C25alkenyl. 19. The compound or salt of any one of claims 1-14, wherein R1 is 1-nonyl or 1-decyl. 20. The compound or salt of any one of claims 1-19, wherein o is 2-15. 21. The compound or salt of any one of claims 1-19, wherein o is 10-15. 22. The compound or salt of any one of claims 1-19, wherein o is 2-10. 23. The compound or salt of any one of claims 1-19, wherein o is 2-5. 24. The compound or salt of any one of claims 1-23, wherein L2 is -(C=O)-O- , -(C=O)N(H)N(R4)(R5)-, -(C=O)N(H)-N=C(R4)-, -(C=O)N(H)N(H)C(R4)(R5)-, or -(C=O)-O-CH2-Rz. 25. The compound or salt of any one of claims 1-23, wherein L2 is -(C=O)-O-. 26. The compound or salt of any one of claims 1-23, wherein L2 is -(C=O)N(H)N(R4)(R5)-. 27. The compound or salt of any one of claims 1-23, wherein L2 is -(C=O)-O-CH2-Rz. 28. The compound or salt of any one of claims 1-27, wherein a is H. 29. The compound or salt of any one of claims 1-27, wherein a is F. 30. The compound or salt of any one of claims 1-29, wherein b is H. 31. The compound or salt of any one of claims 1-29, wherein b is F. 32. The compound or salt of any one of claims 1-31, wherein R6 is C2-C25hydrocarbyl. 33. The compound or salt of any one of claims 1-31, wherein R6 is C5-C25hydrocarbyl. 34. The compound or salt of any one of claims 1-31, wherein R6 is C2-C25alkyl. 35. The compound or salt of any one of claims 1-31, wherein R6 is C5-C25alkyl. 36. The compound or salt of any one of claims 1-31, wherein R6 is C5-C25alkenyl. 37. The compound or salt of any one of claims 1-14 wherein: is selected from the group consisting of: 399.. | Th hee comp poouunndd or r sal ltt of f any y one e of f claims s 1-144 wh hereerieni:n: is sel lect teedd from the e group p con nssiissttiing g of f:: T e e CC OO E e S e e e C 40. The compound or salt of any one of claims 1-39, wherein Y is -CH2-. 41. The compound or salt of any one of claims 1-39, wherein Y is -C(=O)-. 42. The compound or salt of any one of claims 1-39, wherein Y is -O-. 43. The compound or salt of any one of claims 1-42, wherein n is 2-15. 44. The compound or salt of any one of claims 1-42, wherein n is 10-15. 45. The compound or salt of any one of claims 1-42, wherein n is 2-10. 46. The compound or salt of any one of claims 1-42, wherein n is 2-5. 47. The compound or salt of any one of claims 1-46, wherein L1 is absent; and L2 is - (C=O)-O-, -(C=O)N(H)N(R4)(R5)-, -(C=O)N(H)-N=C(R4)-, -(C=O)N(H)N(H)C(R4)(R5)-, or -(C=O)-O-CH2-Rz. 48. The compound or salt of any one of claims 1-46, wherein L1 is -(C=O)-O- , -(C=O)N(H)N(R4)(R5)-, -(C=O)N(H)-N=C(R4)-, -(C=O)N(H)N(H)C(R4)(R5)-, or - (C=O)-O-CH2-Ra; and L2 is absent. 49. The compound or salt of any one of claims 1-46, wherein L1 is -(C=O)-O- , -(C=O)N(H)N(R4)(R5)-, -(C=O)N(H)-N=C(R4)-, -(C=O)N(H)N(H)C(R4)(R5)-, or - (C=O)-O-CH2-Ra. 50. The compound or salt of any one of claims 1-46, wherein L1 is -(C=O)-O. 51. The compound or salt of any one of claims 1-46, wherein L1 is -(C=O)N(H)N(R4)(R5)-. 52. The compound or salt of any one of claims 1-46, wherein L1 is -(C=O)-O-CH2-Rz. 53. The compound or salt of any one of claims 1-52, wherein c is H. 54. The compound or salt of any one of claims 1-52, wherein c is F. 55. The compound or salt of any one of claims 1-54, wherein d is H. 56. The compound or salt of any one of claims 1-54, wherein d is F. 57. The compound or salt of any one of claims 1-56, wherein R7 is C2-C25hydrocarbyl. 58. The compound or salt of any one of claims 1-56, wherein R7 is C5-C25hydrocarbyl. 59. The compound or salt of any one of claims 1-56, wherein R7 is C2-C25alkyl. 60. The compound or salt of any one of claims 1-56, wherein R7 is C5-C25alkyl. 61. The compound or salt of any one of claims 1-56, wherein R7 is C5-C25alkenyl. 62. The compound or salt of any one of claims 1-39, wherein: is selected from the group consisting of: . 64. The compound or salt of any one of claims 1-37, wherein: is selected from the group consisting of: . 65. The compound or salt of any one of claims 1-46 and 53-61, wherein R4 is C2- C25hydrocarbyl. 66. The compound or salt of any one of claims 1-46 and 53-61, wherein R4 is C5- C25hydrocarbyl. 67. The compound or salt of any one of claims 1-46 and 53-61, wherein R4 is C2-C25alkyl. 68. The compound or salt of any one of claims 1-46 and 53-61, wherein R4 is C5-C25alkyl. 69. The compound or salt of any one of claims 1-46 and 53-61, wherein R4 is C5- C25alkenyl. 70. The compound or salt of any one of claims 1-46 and 53-61, wherein R5 is C2- C25hydrocarbyl. 71. The compound or salt of any one of claims 1-46 and 53-61, wherein R5 is C5- C25hydrocarbyl. 72. The compound or salt of any one of claims 1-46 and 53-61, wherein R5 is C2-C25alkyl. 73. The compound or salt of any one of claims 1-46 and 53-61, wherein R5 is C5-C25alkyl. 74. The compound or salt of any one of claims 1-46 and 53-61, wherein R5 is C5- C25alkenyl. 75. The compound or salt of any one of claims 1-23 and 28-36, wherein R4’ is C2- C25hydrocarbyl. 76. The compound or salt of any one of claims 1-23 and 28-36, wherein R4’ is C5- C25hydrocarbyl. 77. The compound or salt of any one of claims 1-23 and 28-36, wherein R4’ is C2- C25alkyl. 78. The compound or salt of any one of claims 1-23 and 28-36, wherein R4’ is C5- C25alkyl. 79. The compound or salt of any one of claims 1-23 and 28-36, wherein R4’ is C5- C25alkenyl. 80. The compound or salt of any one of claims 1-23 and 28-36, wherein R5’ is C2- C25hydrocarbyl. 81. The compound or salt of any one of claims 1-23 and 28-36, wherein R5’ is C5- C25hydrocarbyl. 82. The compound or salt of any one of claims 1-23 and 28-36, wherein R5’ is C2- C25alkyl. 83. The compound or salt of any one of claims 1-23 and 28-36, wherein R5’ is C5- C25alkyl. 84. The compound or salt of any one of claims 1-23 and 28-36, wherein R5’ is C5- C25alkenyl. 85. The compound or salt of any one of claims 1-46 and 53-61, wherein Rz is phenyl that is substituted with 1 or 2 groups independently selected from C2-C10hydrocarbyl. 86. The compound or salt of claim 85, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10hydrocarbyl. 87. The compound or salt of claim 85, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C2-C10alkyl. 88. The compound or salt of claim 85, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10alkyl. 89. The compound or salt of claim 85, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10alkenyl. 90. The compound or salt of any one of claims 1-23 and 28-36, wherein Rz’ is phenyl that is substituted with 1 or 2 groups independently selected from C2-C10hydrocarbyl. 91. The compound or salt of claim 90, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10hydrocarbyl. 92. The compound or salt of claim 90, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C2-C10alkyl. 93. The compound or salt of claim 90, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10alkyl. 94. The compound or salt of claim 90, wherein each C2-C10hydrocarbyl is independently selected from the group consisting of C5-C10alkenyl. 955.. | Ac coommpopuonudnd sel lect teedd from the e group p con nssiissttiing g of f:: Seeees eetcces I Z N or a salt thereof. 96. The compound or salt of claim 1, which is the compound: or a salt thereof. 97. The compound or salt of claim 1, which is the compound: or a salt thereof. 98. The compound or salt of claim 1, which is the compound: or a salt thereof. 99. The compound or salt of claim 1, which is the compound: or a salt thereof. 100. The compound or salt of claim 1, which is the compound: or a salt thereof. 101. The compound or salt of claim 1, which is the compound: or a salt thereof. 102. The compound or salt of claim 1, which is the compound: or a salt thereof. 103. The compound or salt of claim 1, which is the compound: or a salt thereof. 104. A nucleic acid-lipid particle comprising: (a) one or more nucleic acid molecules; (b) a non-cationic lipid; (c) a conjugated lipid; and (d) a compound or salt as described in any one of claims 1-103, wherein the one or more nucleic acid molecules are encapsulated within the lipid particle. 105. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from about 30 mol % to about 85 mol % of the total lipid present in the particle; the non- cationic lipid comprises from about 13 mol % to about 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 0.1 mol % to about 10 mol % of the total lipid present in the particle. 106. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from about 30 mol % to about 85 mol % of the total lipid present in the particle; the non- cationic lipid comprises from about 13 mol % to about 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 0.1 mol % to about 10 mol % of the total lipid present in the particle. 107. The nucleic acid-lipid particle of any one of claims 104-106, wherein the nucleic acid is selected from the group consisting of small interfering RNA (siRNA), Dicer-substrate dsRNA, small hairpin RNA (shRNA), asymmetrical interfering RNA (aiRNA), microRNA (miRNA), mRNA, tRNA, rRNA, viral RNA (vRNA), self-amplifying RNA, and combinations thereof. 108. The nucleic acid-lipid particle of claim 107, wherein the nucleic acid is an mRNA molecule. 109. The nucleic acid-lipid particle of claim 107, wherein the nucleic acid comprises a double stranded siRNA molecule. 110. The nucleic acid-lipid particle of claim 109, wherein the double stranded siRNA molecule comprises at least one modified nucleotide. 111. The nucleic acid-lipid particle of claim 110, wherein the siRNA comprises at least one 2’-O-methyl (2’OMe) nucleotide. 112. The nucleic acid-lipid particle of any one of claims 104-111, wherein the non-cationic lipid comprises cholesterol or a derivative thereof. 113. The nucleic acid-lipid particle of claim 112, wherein the cholesterol or derivative thereof comprises from about 31.5 mol % to about 42.5 mol % of the total lipid present in the particle. 114. The nucleic acid-lipid particle of any one of claims 104-111, wherein the non-cationic lipid comprises a phospholipid. 115. The nucleic acid-lipid particle of any one of claims 104-111, wherein the non-cationic lipid comprises a mixture of a phospholipid and cholesterol or a derivative thereof. 116. The nucleic acid-lipid particle of claim 115 wherein the phospholipid comprises dipalmitoylphosphatidylcholine (DPPC), distearoylphosphatidylcholine (DSPC), or a mixture thereof. 117. The nucleic acid-lipid particle of claim 115, wherein the phospholipid comprises from about 4 mol % to about 10 mol % of the total lipid present in the particle and the cholesterol comprises from about 30 mol % to about 40 mol % of the total lipid present in the particle. 118. The nucleic acid-lipid particle of claim 115, wherein the phospholipid comprises from about 10 mol % to about 30 mol % of the total lipid present in the particle and the cholesterol comprises from about 10 mol % to about 30 mol % of the total lipid present in the particle. 119. The nucleic acid-lipid particle of any one of claims 104-118, wherein the conjugated lipid comprises a polyethyleneglycol (PEG)-lipid conjugate. 120. The nucleic acid-lipid particle of claim 119, wherein the PEG-lipid conjugate comprises a PEG-diacylglycerol (PEG-DAG) conjugate, a PEG-dialkyloxypropyl (PEG- DAA) conjugate, or a mixture thereof. 121. The nucleic acid-lipid particle of claim 120, wherein the PEG-DAA conjugate comprises a PEG-dimyristyloxypropyl (PEG-DMA) conjugate, a PEG-distearyloxypropyl (PEG-DSA) conjugate, or a mixture thereof. 122. The nucleic acid-lipid particle of claim 120, wherein the PEG-DAA conjugate comprises a PEG-dimyristyloxypropyl (PEG-DMA) conjugate. 123. The nucleic acid-lipid particle of claim 119, wherein the polyethyleneglycol (PEG)- lipid conjugate is a compound of formula: A-B-C or a salt thereof, wherein: A is (C1-C6)alkyl, (C3-C8)cycloalkyl, (C3-C8)cycloalkyl(C1-C6)alkyl, (C1-C6)alkoxy, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl , (C1-C6)alkylthio , or (C2-C6)alkanoyloxy, wherein any (C1-C6)alkyl, (C3-C8)cycloalkyl, (C3-C8)cycloalkyl(C1- C6)alkyl, (C1-C6)alkoxy, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, (C1-C6)alkylthio, and (C2-C6)alkanoyloxy is substituted with one or more anionic precursor groups, and wherein any (C1-C6)alkyl, (C3-C8)cycloalkyl, (C3- C8)cycloalkyl(C1-C6)alkyl, (C1-C6)alkoxy, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkanoyl, (C1-C6)alkoxycarbonyl, (C1-C6)alkylthio, and (C2-C6)alkanoyloxy is optionally substituted with one or more groups independently selected from the group consisting of halo, hydroxyl, (C1-C3)alkoxy, (C1-C6)alkanoyl, (C1-C3)alkoxycarbonyl , (C1-C3)alkylthio , or (C2- C3)alkanoyloxy; B is a polyethylene glycol chain having a molecular weight of from about 550 daltons to about 10,000 daltons; C is –L-Ra L is selected from the group consisting of a direct bond, -C(O)O-, -C(O)NRb-, -NRb-, -C(O)-, -NRbC(O)O-, -NRbC(O)NRb-, -S-S-, -O-, -(O)CCH2CH2C(O)-, and -NHC(O)CH2CH2C(O)NH-; Ra is a branched (C10-C50)alkyl or branched (C10-C50)alkenyl wherein one or more carbon atoms of the branched (C10-C50)alkyl or branched (C10-C50)alkenyl have been replaced with –O-; and each Rb is independently H or (C1-C6)alkyl. 124. The nucleic acid-lipid particle of any one of claims 104-123, wherein the PEG has an average molecular weight of about 2,000 daltons. 125. The nucleic acid-lipid particle of any one of claims 104-118, wherein the conjugated lipid comprises a PEG-lipid conjugate selected from: or a salt thereof. 126. The nucleic acid-lipid particle of any one of claims 93-107, wherein the conjugated lipid comprises a compound of the following formula: wherein n is 45-50. 127. The nucleic acid-lipid particle of any one of claims 104-126, wherein the conjugated lipid comprises from about 1 mol % to about 2 mol % of the total lipid present in the particle. 128. The nucleic acid-lipid particle of any one of claims 104-127, wherein the nucleic acid in the nucleic acid-lipid particle is not substantially degraded after incubation of the particle in serum at 37°C for 30 minutes. 129. The nucleic acid-lipid particle of any one of claims 104-128, wherein the nucleic acid is fully encapsulated in the nucleic acid-lipid particle. 130. The nucleic acid-lipid particle of any one of claims 104-129, wherein the nucleic acid- lipid particle has a lipid:nucleic acid mass ratio of from about 5 to about 15. 131. The nucleic acid-lipid particle of any one of claims 104-129, wherein the nucleic acid- lipid particle has a lipid:nucleic acid mass ratio of from about 5 to about 30. 132. The nucleic acid-lipid particle of any one of claims 104-131, wherein the nucleic acid- lipid particle has a median diameter of from about 40 nm to about 150 nm. 133. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from about 56.5 mol % to about 66.5 mol % of the total lipid present in the particle; the non- cationic lipid comprises cholesterol or a derivative thereof comprising from about 31.5 mol % to about 42.5 mol % of the total lipid present in the particle; and a PEG-lipid conjugate comprises from about 1 mol % to about 2 mol % of the total lipid present in the particle. 134. The nucleic acid-lipid particle of claim 133, wherein the nucleic acid-lipid particle comprises about 61.5 mol % compound or salt, about 36.9% cholesterol or a derivative thereof, and about 1.5 mol % PEG-lipid conjugate. 135. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from about 52 mol % to about 62 mol % of the total lipid present in the particle; the non- cationic lipid comprises mixture of a phospholipid and cholesterol or a derivative thereof comprising from about 36 mol % to about 47 mol % of the total lipid present in the particle; and the PEG-lipid conjugate comprising from about 1 mol % to about 2 mol % of the total lipid present in the particle. 136. The nucleic acid-lipid particle of claim 135, wherein the nucleic acid-lipid particle comprises about 57.1 mol % compound or salt, about 7.1 mol % phospholipid, about 34.3 mol % cholesterol or a derivative thereof, and about 1.4 mol % PEG-lipid conjugate. 137. The nucleic acid-lipid particle of claim 135, wherein the nucleic acid-lipid particle comprises about 57.1 mol % compound or salt, about 20 mol % phospholipid, about 20 mol % cholesterol or a derivative thereof, and about 1.4 mol % PEG-lipid conjugate. 138. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprises a mixture of a phospholipid and cholesterol or a derivative thereof, wherein the phospholipid comprises from 4 mol % to 10 mol % of the total lipid present in the particle and the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. 139. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprising a mixture of a phospholipid and cholesterol or a derivative thereof, wherein the phospholipid comprises from 3 mol % to 15 mol % of the total lipid present in the particle and the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. 140. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprises up to 49.5 mol % of the total lipid present in the particle; the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. 141. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from 50 mol % to 85 mol % of the total lipid present in the particle; the non-cationic lipid comprises from 13 mol % to 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. 142. The nucleic acid-lipid particle of claim 104, wherein the compound or salt comprises from about 30 mol % to about 50 mol % of the total lipid present in the particle; the non- cationic lipid comprises mixture of a phospholipid and cholesterol or a derivative thereof comprising from about 47 mol % to about 69 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 1 mol % to about 3 mol % of the total lipid present in the particle. 143. The nucleic acid-lipid particle of claim 104, wherein the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000 daltons wherein the conjugated lipid comprises about 2 mol % of the total lipid present in the particle; DSPC comprises about 10 mol % of the total lipid present in the particle; cholesterol comprises about 48 mol % of the total lipid present in the particle; and the compound or salt comprises about 40 mol % of the total lipid present in the particle. 144. The nucleic acid-lipid particle of claim 104, wherein the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000 daltons; wherein the conjugated lipid comprises about 2 mol % of the total lipid present in the particle; DSPC comprises about 10 mol % of the total lipid present in the particle; cholesterol comprises about 48 mol % of the total lipid present in the particle; and the compound or salt comprises about 40 mol % of the total lipid present in the particle. 145. The nucleic acid-lipid particle of claim 104, wherein the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: ; wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000; wherein the conjugated lipid comprises about 1.6 mol % of the total lipid present in the particle; DSPC comprises about 10.9 mol % of the total lipid present in the particle; cholesterol comprises about 32.8 mol % of the total lipid present in the particle; and the compound or salt comprises about 54.9 mol % of the total lipid present in the particle. 146. The nucleic acid-lipid particle of any one of claims 142-145, wherein the lipid to nucleic acid ratio is about 24. 147. The nucleic acid-lipid particle of any one of claims 104-146 that comprises two or more compounds or salts as described in any one of claims 1-103. 148. A pharmaceutical composition comprising a nucleic acid-lipid particle of any one of claims 104-147, and a pharmaceutically acceptable carrier. 149. A method for introducing a nucleic acid into a cell, the method comprising: contacting the cell with a nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148. 150. The method of claim 149, wherein the cell is in a mammal. 151. A method for the in vivo delivery of a nucleic acid, the method comprising: administering to a mammalian subject a nucleic acid-lipid particle of any one of claims any one of claims 104-147or the composition of claim 148. 152. The method of claim 151, wherein the administration is selected from the group consisting of oral, intranasal, intravenous, intraperitoneal, intramuscular, intra-articular, intralesional, intratracheal, subcutaneous, and intradermal. 153. A nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148, for use in the in vivo delivery of a nucleic acid to a mammal. 154. The use of a nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148, to prepare a medicament for the in vivo delivery of a nucleic acid to a mammal. 155. A method for treating a disease or disorder in a mammalian subject in need thereof, the method comprising: administering to the mammalian subject a therapeutically effective amount of a nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148. 156. The method of claim 155, wherein the disease or disorder is selected from the group consisting of a viral infection, a liver disease or disorder, and cancer. 157. A nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148, for use in treating a disease or disorder in a mammal. 158. The use of a nucleic acid-lipid particle of any one of claims 104-147 or the composition of claim 148, to prepare a medicament for treating a disease or disorder in a mammal. |
. is sel lect teedd from the e group p con nssiissttiing g of f:: r e e e e
. In one embodiment, Y is -CH 2 -. In one embodiment, Y is -C(=O)-. In one embodiment, Y is -O-. In one embodiment, n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. In one embodiment, n is 10, 11, 12, 13, 14, or 15. In one embodiment, n is 2, 3, 4, 5, 6, 7, 8, 9, or 10. In one embodiment, n is 2, 3, 4, or 5. In one embodiment, L 1 is absent; and L 2 is -(C=O)-O-, -(C=O)N(H)N(R 4 )-, -(C=O)N(H)- N=C(R 4 )-, -(C=O)N(H)N(H)C(R 4 )(R 5 )-, or -(C=O)-O-CH 2 -R z . In one embodiment, L 1 is -(C=O)-O-, -(C=O)N(H)N(R 4 )-, -(C=O)N(H)- N=C(R 4 )-, -(C=O)N(H)N(H)C(R 4 )(R 5 )-, or -(C=O)-O-CH 2 -R a ; and L 2 is absent. In one embodiment, L 1 is -(C=O)-O-, -(C=O)N(H)N(R 4 )-, -(C=O)N(H)- N=C(R 4 )-, -(C=O)N(H)N(H)C(R 4 )(R 5 )-, or -(C=O)-O-CH 2 -R a . In one embodiment, L 1 is -(C=O)-O. In one embodiment, L 1 is -(C=O)N(H)N(R 4 )-. In one embodiment, L 1 is -(C=O)-O-CH 2 -R z . In one embodiment, c is H. In one embodiment, c is F. In one embodiment, d is H. In one embodiment, d is F. In one embodiment, R 7 is C 2 -C 25 hydrocarbyl. In one embodiment, R 7 is C 5 -C 25 hydrocarbyl. In one embodiment, R 7 is C 2 -C 25 alkyl. In one embodiment, R 7 is C 5 -C 25 alkyl. In one embodiment, R 7 is C 5 -C 25 alkenyl. In one embodiment, the group: In one embodiment, R 4 is C 2 -C 25 hydrocarbyl. In one embodiment, R 4 is C 5 -C 25 hydrocarbyl. In one embodiment, R 4 is C 2 -C 25 alkyl. In one embodiment, R 4 is C 5 -C 25 alkyl. In one embodiment, R 4 is C 5 -C 25 alkenyl. In one embodiment, R 5 is C 2 -C 25 hydrocarbyl. In one embodiment, R 5 is C 5 -C 25 hydrocarbyl. In one embodiment, R 5 is C 2 -C 25 alkyl. In one embodiment, R 5 is C 5 -C 25 alkyl. In one embodiment, R 5 is C 5 -C 25 alkenyl. In one embodiment, R 4’ is C 2 -C 25 hydrocarbyl. In one embodiment, R’ 4 is C 5 -C 25 hydrocarbyl. In one embodiment, R 4’ is C 2 -C 25 alkyl. In one embodiment, R 4’ is C 5 -C 25 alkyl. In one embodiment, R 4’ is C 5 -C 25 alkenyl. In one embodiment, R’ 5 is C 2 -C 25 hydrocarbyl. In one embodiment, R’ 5’ is C 5 -C 25 hydrocarbyl. In one embodiment, R 5’ is C 2 -C 25 alkyl. In one embodiment, R 5 is C 5 -C 25 alkyl. In one embodiment, R 5’ is C 5 -C 25 alkenyl. In one embodiment, R z is phenyl that is substituted with 1 or 2 groups independently selected from C 2 -C 10 hydrocarbyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 -C 10 hydrocarbyl. In one embodiment, each C 2 - C 10 hydrocarbyl is independently selected from the group consisting of C 2 -C 10 alkyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 - C 10 alkyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 -C 10 alkenyl. In one embodiment, R z’ is phenyl that is substituted with 1 or 2 groups independently selected from C 2 -C 10 hydrocarbyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 -C 10 hydrocarbyl. In one embodiment, each C 2 - C 10 hydrocarbyl is independently selected from the group consisting of C 2 -C 10 alkyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 - C 10 alkyl. In one embodiment, each C 2 -C 10 hydrocarbyl is independently selected from the group consisting of C 5 -C 10 alkenyl. In one embodiment, the ionizable lipid is selected from the compounds of Examples 1, 16, 17, 43, 46, 90, 101, and 115, and salts thereof. In one embodiment, X is -C(=O)- and Y is absent or -O-. In one embodiment, X is -C(=O)- and Y is -O-. In one embodiment, Y is -CH 2 -; L 1 is absent; and c and d are each H. In one embodiment, a is F or b is H. In one embodiment, a is F and b is F. In one embodiment, a is F; b is H; and L 1 is -(C=O)-O-. In one embodiment, a is F; b is F; and L 1 is -(C=O)-O-. In one embodiment, R 2 and R 3 are each methyl. In one embodiment, L 1 is absent; and c and d are each H. In one embodiment, L 1 is absent; and a, b, c, and d are each H. In one embodiment, one of L 1 and L 2 is -(C=O)-O-. In one embodiment, L 1 is -(C=O)-O- and R 7 is a branched C 2 -C 25 hydrocarbyl. In one embodiment, L 1 is -(C=O)-O- and R 7 is a C 5 -C 25 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to L 1 . In one embodiment, L 1 is -(C=O)-O- and R 7 is a C4-C 25 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to L 1 . In one embodiment, L 1 is -(C=O)-O- and R 7 is a C 3 -C 25 hydrocarbyl that is branched at a carbon that is attached to L 1 . In one embodiment, one of L 1 and L 2 is -(C=O)-O- and R 7 is a branched C 2 - C 25 hydrocarbyl. In one embodiment, one of L 1 and L 2 is -(C=O)-O- and R 7 is a C 5 -C 25 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to L 1 . In one embodiment, one of L 1 and L 2 is -(C=O)-O- and R 7 is a C4-C 25 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to L 1 . In one embodiment, one of L 1 and L 2 is -(C=O)-O- and R 7 is a C 3 -C 25 hydrocarbyl that is branched at a carbon that is attached to L 1 . In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 2 - C 25 hydrocarbyl. In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 5 - C 15 hydrocarbyl. In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 10 hydrocarbyl. In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 5 - C 15 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to the remainder of the compound of formula (I). In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 5 - C 1 5hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to the remainder of the compound of formula (I). In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 5 - C 1 5hydrocarbyl that is branched at a carbon that is attached to the remainder of the compound of formula (I). In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 10 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to the remainder of the compound of formula (I). In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 10 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to the remainder of the compound of formula (I). In one embodiment, Y is absent or -O-; N is 0; c is H; d is H; L 1 is absent; and R 7 is C 10 hydrocarbyl that is branched at a carbon that is attached to the remainder of the compound of formula (I). In one embodiment, L 2 is -(C=O)-O- and R 6 is a branched C 2 -C 25 hydrocarbyl. In one embodiment, L 2 is -(C=O)-O- and R 6 is a C 5 -C 25 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to L 2 . In one embodiment, L 2 is -(C=O)-O- and R 6 is a C 4 -C 25 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to L 2 . In one embodiment, L 2 is -(C=O)-O- and R 6 is a C 3 -C 25 hydrocarbyl that is branched at a carbon that is attached to L 2 . In one embodiment, L 2 is -(C=O)-O-; a is F; b is H; and R 6 is a branched C 2 - C 25 hydrocarbyl. In one embodiment, L 2 is -(C=O)-O-; a is F; b is H; and R 6 is a C 5 -C 25 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to L 2 . In one embodiment, one of L 2 is -(C=O)-O-; a is F; b is H; and R 6 is a C4-C 25 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to L 2 . In one embodiment, L 2 is -(C=O)-O-; a is F; b is H; and R 6 is a C 3 -C 25 hydrocarbyl that is branched at a carbon that is attached to L 2 . In one embodiment, L 2 is -(C=O)-O-; a is F; b is F; and R 6 is a branched C 2 - C 25 hydrocarbyl. In one embodiment, L 2 is -(C=O)-O-; a is F; b is F; and R 6 is a C 5 -C 25 hydrocarbyl that is branched at a carbon that is within 3 carbons of the point of attachment to L 2 . In one embodiment, L 2 is -(C=O)-O-; a is F; b is F; and R 6 is a C4-C 25 hydrocarbyl that is branched at a carbon that is within 2 carbons of the point of attachment to L 2 . In one embodiment, L 2 is -(C=O)-O-; a is F; b is F; and R 6 is a C 3 -C 25 hydrocarbyl that is branched at a carbon that is attached to L 2 . In one embodiment, the invention provides a compound of formula (I): or a salt thereof, wherein: X is -CH 2 -, -O-, -O(C=O); or -C(=O)- Y is -CH 2 -, -O-, -SO2-, or -C(=O)-; R 1 is C 2 -C 25 hydrocarbyl; R 2 is C 1 -C 3 alkyl; and R 3 is C 1 -C 3 alkyl; or R 2 and R 3 taken together with the nitrogen to which they are attached form a a aziridino, azetidino, or pyrrolidino ring; m is 0, 1, 2, 3, 4, 5 or 6; n is 0-15; o is 0-15; L 1 is absent, -(C=O)-O-, -(C=O)N(H)N(R 4 )-, -(C=O)N(H)- N=C(R 4 )-, -(C=O)N(H)N(H)C(R 4 )(R 5 )-, -(C=O)-O-CH 2 -R z , or -O(C=O)-R w -; L 2 is absent, -(C=O)-O-, -(C=O)N(H)N(R 4’ )-, -(C=O)N(H)- a is H or F; b is H or F; c is H or F; and d is H or F; or c and d taken together with the carbon to which they are attached form -C(=O)-; R 4 is H or C 2 -C 25 hydrocarbyl; R 5 is H or C 2 -C 25 hydrocarbyl; R 4’ is H or C 2 -C 25 hydrocarbyl; R 5’ is H or C 2 -C 25 hydrocarbyl; R 6 is C 2 -C 25 hydrocarbyl; R 7 is C 2 -C 25 hydrocarbyl; R w is absent, -C(F)H-, or -C(F) 2 -; R x is absent, -C(F)H-, or -C(F) 2 -; R z is phenyl that is substituted with 1, 2, or 3 groups independently selected from C 2 - C 10 hydrocarbyl; and R z’ is phenyl that is substituted with 1, 2, or 3 groups independently selected from C 2 - C 10 hydrocarbyl. In one embodiment, the invention provides a compound of formula (I): or a salt thereof, wherein: X is -CH 2 -, -O-, -O(C=O); or -C(=O)- Y is -CH 2 -, -O-, -SO 2 -, or -C(=O)-; R 1 is C 2 -C 25 hydrocarbyl; R 2 is C 1 -C 3 alkyl; and R 3 is C 1 -C 3 alkyl; or R 2 and R 3 taken together with the nitrogen to which they are attached form a a aziridino, azetidino, or pyrrolidino ring; m is 0, 1, 2, 3, 4, 5 or 6; n is 0-15; o is 0-15; L 1 is absent or -(C=O)-O-; L 2 is absent or -(C=O)-O-; a is H or F; b is H or F; c is H or F; and d is H or F; or c and d taken together with the carbon to which they are attached form -C(=O)-; R 4 is H or C 2 -C 25 hydrocarbyl; R 5 is H or C 2 -C 25 hydrocarbyl; R 4’ is H or C 2 -C 25 hydrocarbyl; R 5’ is H or C 2 -C 25 hydrocarbyl; R 6 is C 2 -C 25 hydrocarbyl; R 7 is C 2 -C 25 hydrocarbyl; R w is absent, -C(F)H-, or -C(F) 2 -; R x is absent, -C(F)H-, or -C(F) 2 -; R z is phenyl that is substituted with 1, 2, or 3 groups independently selected from C 2 - C 10 hydrocarbyl; and R z’ is phenyl that is substituted with 1, 2, or 3 groups independently selected from C 2 - C 10 hydrocarbyl. Specific Embodiments In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein X is -C(=O)-. Such ionizable lipids typically demonstrate high activity. In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein X is -C(=O)- and Y is -O-. Such ionizable lipids typically demonstrate high activity and possess desirable pKa properties. In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein Y is -CH 2 -; L 1 is absent; and c and d are each H. Such ionizable lipids typically demonstrate high activity. In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein R 2 is methyl and R 3 is methyl. Such ionizable lipids typically demonstrate high activity. In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein L 1 is absent; and c and d are each H. Such ionizable lipids typically demonstrate high activity. In one specific embodiment, the invention provides an ionizable lipid of formula (I), wherein L 2 is -(C=O)-O- and R 6 is a C 2 -C 25 hydrocarbyl that is branched at a carbon atom that is attached to L 2 or that is branched at a carbon atom that is 2 carbons from the point of attachment to L 2 or that is branched at a carbon atom that is 3 carbons from the point of attachment to L 2 . Such ionizable lipids typically demonstrate high activity. When a hydrocarbyl is branched at a carbon atom that is attached to L 1 or L 2 , or is branched at a carbon atom that is 2 carbons from the point of attachment to L 1 or L 2 , or is branched at a carbon atom that is 3 carbons from the point of attachment to L 1 or L 2 , it is understood that the hydrocarbyl is branched at one of the carbons illustrated in the following formula: In one embodiment, the invention provides a nucleic acid-lipid particle comprising: (a) one or more nucleic acid molecules; (b) a non-cationic lipid; (c) a conjugated lipid; and (d) a compound of formula (I) or salt thereof, wherein the one or more nucleic acid molecules are encapsulated within the lipid particle. In one embodiment, the compound or salt comprises from about 30 mol % to about 85 mol % of the total lipid present in the particle; the non-cationic lipid comprises from about 13 mol % to about 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 0.1 mol % to about 10 mol % of the total lipid present in the particle. In one embodiment, the compound or salt comprises from about 30 mol % to about 85 mol % of the total lipid present in the particle; the non-cationic lipid comprises from about 13 mol % to about 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 0.1 mol % to about 10 mol % of the total lipid present in the particle. In one embodiment, the nucleic acid is selected from the group consisting of small interfering RNA (siRNA), Dicer-substrate dsRNA, small hairpin RNA (shRNA), asymmetrical interfering RNA (aiRNA), microRNA (miRNA), mRNA, tRNA, rRNA, viral RNA (vRNA), self-amplifying RNA, and combinations thereof. In one embodiment, the nucleic acid is an mRNA molecule. In one embodiment, the nucleic acid comprises a double stranded siRNA molecule. In one embodiment, the double stranded siRNA molecule comprises at least one modified nucleotide. In one embodiment, the siRNA comprises at least one 2’-O-methyl (2’OMe) nucleotide. In one embodiment, the non-cationic lipid comprises cholesterol or a derivative thereof. In one embodiment, the cholesterol or derivative thereof comprises from about 31.5 mol % to about 42.5 mol % of the total lipid present in the particle. In one embodiment, the non-cationic lipid comprises a phospholipid. In one embodiment, the non-cationic lipid comprises a mixture of a phospholipid and cholesterol or a derivative thereof. In one embodiment, the phospholipid comprises dipalmitoylphosphatidylcholine (DPPC), distearoylphosphatidylcholine (DSPC), or a mixture thereof. In one embodiment, the phospholipid comprises from about 4 mol % to about 10 mol % of the total lipid present in the particle and the cholesterol comprises from about 30 mol % to about 40 mol % of the total lipid present in the particle. In one embodiment, the phospholipid comprises from about 10 mol % to about 30 mol % of the total lipid present in the particle and the cholesterol comprises from about 10 mol % to about 30 mol % of the total lipid present in the particle. In one embodiment, the conjugated lipid comprises a polyethyleneglycol (PEG)-lipid conjugate. In one embodiment, the PEG-lipid conjugate comprises a compound of formula (I): or a salt thereof, wherein: R 1 is H, (C 1 -C 6 )alkyl, or (C 1 -C 6 )alkanoyl; n is an integer in the range of from about 10 to about 150; and L is absent and X is -C(=O)NR 2 R 3 ; or L is (C 1 -C 6 )alkyl and X is selected from the group consisting of -N(R 4 )C(=O)CH(R 2 )(R 3 ), -OCH(R 2 )(R 3 ), -C(=O)OCH 2 CH(R 2 )(R 3 ), -N(R 4 )C(=O)N(R 2 )(R 3 ), and -SO2N(R 2 )(R 3 ); R 2 is (C 10 -C 20 )alkyl; R 3 is (C 10 -C 20 )alkyl; and R 4 is H or (C 1 -C 6 )alkyl. In one embodiment, the PEG-lipid conjugate comprises a compound selected from:
or a salt thereof. In one embodiment, the PEG-lipid conjugate comprises a compound of the following formula: wherein n is 45-50. In one embodiment, the PEG-lipid conjugate comprises a PEG-diacylglycerol (PEG- DAG) conjugate, a PEG-dialkyloxypropyl (PEG-DAA) conjugate, or a mixture thereof. In one embodiment, the PEG-DAA conjugate comprises a PEG-dimyristyloxypropyl (PEG-DMA) conjugate, a PEG-distearyloxypropyl (PEG-DSA) conjugate, or a mixture thereof. In one embodiment, the PEG-DAA conjugate comprises a PEG-dimyristyloxypropyl (PEG-DMA) conjugate. In one embodiment, the polyethyleneglycol (PEG)-lipid conjugate is a compound of formula: A-B-C or a salt thereof, wherein: A is (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl , (C 1 -C 6 )alkylthio , or (C 2 -C 6 )alkanoyloxy, wherein any (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 - C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is substituted with one or more anionic precursor groups, and wherein any (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 - C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is optionally substituted with one or more groups independently selected from the group consisting of halo, hydroxyl, (C 1 - C 3 )alkoxy, (C 1 -C 6 )alkanoyl, (C 1 -C 3 )alkoxycarbonyl , (C 1 -C 3 )alkylthio , or (C 2 -C 3 )alkanoyloxy; B is a polyethylene glycol chain having a molecular weight of from about 550 daltons to about 10,000 daltons; C is –L-R a L is selected from the group consisting of a direct bond, -C(O)O-, -C(O)NR b -, -NR b -, - C(O)-, -NR b C(O)O-, -NR b C(O)NR b -, -S-S-, -O-, -(O)CCH 2 CH 2 C(O)-, and -NHC(O)CH 2 CH 2 C(O)NH-; R a is a branched (C 10 -C 50 )alkyl or branched (C 10 -C 50 )alkenyl wherein one or more carbon atoms of the branched (C 10 -C 50 )alkyl or branched (C 10 -C 50 )alkenyl have been replaced with –O-; and each R b is independently H or (C 1 -C 6 )alkyl. In one embodiment, the PEG has an average molecular weight of about 2,000 daltons. In one embodiment, the conjugated lipid comprises from about 1 mol % to about 2 mol % of the total lipid present in the particle. In one embodiment, the nucleic acid in the nucleic acid-lipid particle is not substantially degraded after incubation of the particle in serum at 37°C for 30 minutes. In one embodiment, the nucleic acid is fully encapsulated in the nucleic acid-lipid particle. In one embodiment, the nucleic acid-lipid particle has a lipid:nucleic acid mass ratio of from about 5 to about 15. In one embodiment, the nucleic acid-lipid particle has a lipid:nucleic acid mass ratio of from about 5 to about 30. In one embodiment, the nucleic acid-lipid particle has a median diameter of from about 40 nm to about 150 nm. In one embodiment, the compound or salt comprises from about 56.5 mol % to about 66.5 mol % of the total lipid present in the particle; the non-cationic lipid comprises cholesterol or a derivative thereof comprising from about 31.5 mol % to about 42.5 mol % of the total lipid present in the particle; and a PEG-lipid conjugate comprises from about 1 mol % to about 2 mol % of the total lipid present in the particle. In one embodiment, the nucleic acid-lipid particle comprises about 61.5 mol % compound or salt, about 36.9% cholesterol or a derivative thereof, and about 1.5 mol % PEG- lipid conjugate. In one embodiment, the compound or salt comprises from about 52 mol % to about 62 mol % of the total lipid present in the particle; the non-cationic lipid comprises mixture of a phospholipid and cholesterol or a derivative thereof comprising from about 36 mol % to about 47 mol % of the total lipid present in the particle; and the PEG-lipid conjugate comprising from about 1 mol % to about 2 mol % of the total lipid present in the particle. In one embodiment, the nucleic acid-lipid particle comprises about 57.1 mol % compound or salt, about 7.1 mol % phospholipid, about 34.3 mol % cholesterol or a derivative thereof, and about 1.4 mol % PEG-lipid conjugate. In one embodiment, the nucleic acid-lipid particle comprises about 57.1 mol % compound or salt, about 20 mol % phospholipid, about 20 mol % cholesterol or a derivative thereof, and about 1.4 mol % PEG-lipid conjugate. In one embodiment, the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprises a mixture of a phospholipid and cholesterol or a derivative thereof, wherein the phospholipid comprises from 4 mol % to 10 mol % of the total lipid present in the particle and the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. In one embodiment, the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprising a mixture of a phospholipid and cholesterol or a derivative thereof, wherein the phospholipid comprises from 3 mol % to 15 mol % of the total lipid present in the particle and the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. In one embodiment, the compound or salt comprises from 50 mol % to 65 mol % of the total lipid present in the particle; the non-cationic lipid comprises up to 49.5 mol % of the total lipid present in the particle; the cholesterol or derivative thereof comprises from 30 mol % to 40 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. In one embodiment, the compound or salt comprises from 50 mol % to 85 mol % of the total lipid present in the particle; the non-cationic lipid comprises from 13 mol % to 49.5 mol % of the total lipid present in the particle; and the conjugated lipid comprises from 0.5 mol % to 2 mol % of the total lipid present in the particle. In one embodiment, the compound or salt comprises from about 30 mol % to about 50 mol % of the total lipid present in the particle; the non-cationic lipid comprises mixture of a phospholipid and cholesterol or a derivative thereof comprising from about 47 mol % to about 69 mol % of the total lipid present in the particle; and the conjugated lipid comprises from about 1 mol % to about 3 mol % of the total lipid present in the particle. In one embodiment, the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000 daltons wherein the conjugated lipid comprises about 2 mol % of the total lipid present in the particle; DSPC comprises about 10 mol % of the total lipid present in the particle; cholesterol comprises about 48 mol % of the total lipid present in the particle; and the compound or salt comprises about 40 mol % of the total lipid present in the particle. In one embodiment, the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: ; wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000 daltons; wherein the conjugated lipid comprises about 2 mol % of the total lipid present in the particle; DSPC comprises about 10 mol % of the total lipid present in the particle; cholesterol comprises about 48 mol % of the total lipid present in the particle; and the compound or salt comprises about 40 mol % of the total lipid present in the particle. In one embodiment, the non-cationic lipid comprises a mixture of cholesterol and DSPC; the conjugated lipid is: ; wherein n is selected so that the resulting polymer chain has a molecular weight of about 2000; wherein the conjugated lipid comprises about 1.6 mol % of the total lipid present in the particle; DSPC comprises about 10.9 mol % of the total lipid present in the particle; cholesterol comprises about 32.8 mol % of the total lipid present in the particle; and the compound or salt comprises about 54.9 mol % of the total lipid present in the particle. In one embodiment, the lipid to nucleic acid ratio is about 24. In one embodiment, the nucleic acid-lipid particle comprises two or more different compounds of formula (I) or salts thereof. Non-Cationic Lipids The non-cationic lipids used in the lipid particles of the invention (e.g., LNP) can be any of a variety of neutral uncharged, zwitterionic, or anionic lipids capable of producing a stable complex. Non-limiting examples of non-cationic lipids include phospholipids such as lecithin, phosphatidylethanolamine, lysolecithin, lysophosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, egg sphingomyelin (ESM), cephalin, cardiolipin, phosphatidic acid, cerebrosides, dicetylphosphate, distearoylphosphatidylcholine (DSPC), dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylglycerol (DOPG), dipalmitoylphosphatidylglycerol (DPPG), dioleoylphosphatidylethanolamine (DOPE), palmitoyloleoyl-phosphatidylcholine (POPC), palmitoyloleoyl-phosphatidylethanolamine (POPE), palmitoyloleyol-phosphatidylglycerol (POPG), dioleoylphosphatidylethanolamine 4-(N-maleimidomethyl)-cyclohexane-1-carboxylate (DOPE-mal), dipalmitoyl-phosphatidylethanolamine (DPPE), dimyristoyl- phosphatidylethanolamine (DMPE), distearoyl-phosphatidylethanolamine (DSPE), monomethyl-phosphatidylethanolamine, dimethyl-phosphatidylethanolamine, dielaidoyl- phosphatidylethanolamine (DEPE), stearoyloleoyl-phosphatidylethanolamine (SOPE), lysophosphatidylcholine, dilinoleoylphosphatidylcholine, and mixtures thereof. Other diacylphosphatidylcholine and diacylphosphatidylethanolamine phospholipids can also be used. The acyl groups in these lipids are preferably acyl groups derived from fatty acids having C 10 - C 2 4 carbon chains, e.g., lauroyl, myristoyl, palmitoyl, stearoyl, or oleoyl. Additional examples of non-cationic lipids include sterols such as cholesterol and derivatives thereof such as cholestanol, cholestanone, cholestenone, coprostanol, cholesteryl-2′- hydroxyethyl ether, cholesteryl-4′-hydroxybutyl ether, and mixtures thereof. In some embodiments, the non-cationic lipid present in the lipid particles (e.g., LNP) comprises or consists of cholesterol or a derivative thereof, e.g., a phospholipid-free lipid particle formulation. In other embodiments, the non-cationic lipid present in the lipid particles (e.g., LNP) comprises or consists of one or more phospholipids, e.g., a cholesterol-free lipid particle formulation. In further embodiments, the non-cationic lipid present in the lipid particles (e.g., LNP) comprises or consists of a mixture of one or more phospholipids and cholesterol or a derivative thereof. Other examples of non-cationic lipids suitable for use in the present invention include nonphosphorous containing lipids such as, e.g., linoleyl alcohol, acetyl palmitate, glycerolricinoleate, hexadecyl stereate, isopropyl myristate, amphoteric acrylic polymers, triethanolamine-lauryl sulfate, alkyl-aryl sulfate polyethyloxylated fatty acid amides, ceramide, sphingomyelin, and the like. In some embodiments, the non-cationic lipid comprises from about 13 mol % to about 49.5 mol %, from about 20 mol % to about 45 mol %, from about 25 mol % to about 45 mol %, from about 30 mol % to about 45 mol %, from about 35 mol % to about 45 mol %, from about 20 mol % to about 40 mol %, from about 25 mol % to about 40 mol %, or from about 30 mol % to about 40 mol % of the total lipid present in the particle. In certain embodiments, the cholesterol present in phospholipid-free lipid particles comprises from about 30 mol % to about 45 mol %, from about 30 mol % to about 40 mol %, from about 35 mol % to about 45 mol %, or from about 35 mol % to about 40 mol % of the total lipid present in the particle. As a non-limiting example, a phospholipid-free lipid particle may comprise cholesterol at about 37 mol % of the total lipid present in the particle. In certain other embodiments, the cholesterol present in lipid particles containing a mixture of phospholipid and cholesterol comprises from about 30 mol % to about 40 mol %, from about 30 mol % to about 35 mol %, or from about 35 mol % to about 40 mol % of the total lipid present in the particle. As a non-limiting example, a lipid particle comprising a mixture of phospholipid and cholesterol may comprise cholesterol at about 34 mol % of the total lipid present in the particle. As other non-limiting examples, the particle may comprise cholesterol at either 33% or 38.5%. In further embodiments, the cholesterol present in lipid particles containing a mixture of phospholipid and cholesterol comprises from about 10 mol % to about 30 mol %, from about 15 mol % to about 25 mol %, or from about 17 mol % to about 23 mol % of the total lipid present in the particle. As a non-limiting example, a lipid particle comprising a mixture of phospholipid and cholesterol may comprise cholesterol at about 20 mol % of the total lipid present in the particle. In embodiments where the lipid particles contain a mixture of phospholipid and cholesterol or a cholesterol derivative, the mixture may comprise up to about 40, 45, 50, 55, or 60 mol % of the total lipid present in the particle. In certain instances, the phospholipid component in the mixture may comprise from about 2 mol % to about 20 mol %, from about 2 mol % to about 15 mol %, from about 2 mol % to about 12 mol %, from about 2 mol % to about 10 mol %, from about 2 mol % to about 9 mol %, from about 2 mol % to about 8 mol %, 4 mol % to about 20 mol %, from about 4 mol % to about 15 mol %, from about 4 mol % to about 12 mol %, from about 4 mol % to about 10 mol %, from about 4 mol % to about 9 mol %, from about 4 mol % to about 8 mol %, 6 mol % to about 20 mol %, from about 6 mol % to about 15 mol %, from about 6 mol % to about 12 mol %, from about 6 mol % to about 10 mol %, from about 6 mol % to about 9 mol %, from about 2 mol % to about 8 mol %, 8 mol % to about 20 mol %, from about 8 mol % to about 15 mol %, from about 8 mol % to about 12 mol %, from about 8 mol % to about 10 mol %, from about 8 mol % to about 9 mol % of the total lipid present in the particle. As a non-limiting example, a lipid particle comprising a mixture of phospholipid and cholesterol may comprise a phospholipid such as DPPC or DSPC at about 7 mol % (e.g., in a mixture with about 34 mol % cholesterol) of the total lipid present in the particle. In certain other instances, the phospholipid component in the mixture may comprise from about 10 mol % to about 30 mol %, from about 10 mol % to about 15 mol %, from about 15 mol % to about 20 mol %, from about 15 mol % to about 25 mol %, or from about 17 mol % to about 23 mol % of the total lipid present in the particle. As another non-limiting example, a lipid particle comprising a mixture of phospholipid and cholesterol may comprise a phospholipid such as DPPC or DSPC at about 20 mol % (e.g., in a mixture with about 20 mol % cholesterol) of the total lipid present in the particle. Lipid Conjugate In addition to cationic and non-cationic lipids, the lipid particles of the invention (e.g., LNP) comprise a lipid conjugate. The conjugated lipid is useful in that it prevents the aggregation of particles. Suitable conjugated lipids include, but are not limited to, PEG-lipid conjugates, ATTA-lipid conjugates, cationic-polymer-lipid conjugates (CPLs), POZ polyoxazoline (POZ)-lipids, polysarcosine (pSAR)-lipids and mixtures thereof. In certain embodiments, the particles comprise either a PEG-lipid conjugate or an ATTA-lipid conjugate together with a CPL. In a preferred embodiment, the lipid conjugate is a PEG-lipid. Examples of PEG-lipids include, but are not limited to, PEG coupled to dialkyloxypropyls (PEG-DAA) as described in, e.g., PCT Publication No. WO 05/026372, PEG coupled to diacylglycerol (PEG-DAG) as described in, e.g., U.S. Patent Publication Nos.20030077829 and 2005008689, PEG coupled to phospholipids such as phosphatidylethanolamine (PEG-PE), PEG conjugated to ceramides as described in, e.g., U.S. Pat. No.5,885,613, PEG conjugated to cholesterol or a derivative thereof, and mixtures thereof. The disclosures of these patent documents are herein incorporated by reference in their entirety for all purposes. Additional PEG-lipids include, without limitation, PEG-C-DOMG, 2 KPEG-DMG, and a mixture thereof. PEG is a linear, water-soluble polymer of ethylene glycol repeating units. PEGs are classified by their molecular weights; for example, PEG 2000 has an average molecular weight of about 2,000 daltons, and PEG 5000 has an average molecular weight of about 5,000 daltons. PEGs are commercially available from Sigma Chemical Co. and other companies and include, for example, the following: monomethoxypolyethylene glycol (MePEG-OH), monomethoxypolyethylene glycol-succinate (MePEG-S), monomethoxypolyethylene glycol- succinimidyl succinate (MePEG-S-NHS), monomethoxypolyethylene glycol-amine (MePEG- NH 2 ), monomethoxypolyethylene glycol-tresylate (MePEG-TRES), and monomethoxypolyethylene glycol-imidazolyl-carbonyl (MePEG-IM). Other PEGs such as those described in U.S. Pat. Nos.6,774,180 and 7,053,150 (e.g., mPEG (20 KDa) amine) are also useful for preparing the PEG-lipid conjugates of the present invention. The disclosures of these patents are herein incorporated by reference in their entirety for all purposes. In addition, monomethoxypolyethyleneglycolacetic acid (MePEG-CH 2 COOH) is particularly useful for preparing PEG-lipid conjugates including, e.g., PEG-DAA conjugates. The PEG moiety of the PEG-lipid conjugates described herein may comprise an average molecular weight ranging from about 550 daltons to about 10,000 daltons. In certain instances, the PEG moiety has an average molecular weight of from about 750 daltons to about 5,000 daltons (e.g., from about 1,000 daltons to about 5,000 daltons, from about 1,500 daltons to about 3,000 daltons, from about 750 daltons to about 3,000 daltons, from about 750 daltons to about 2,000 daltons, etc.). In preferred embodiments, the PEG moiety has an average molecular weight of about 2,000 daltons or about 750 daltons. In certain instances, the PEG can be optionally substituted by an alkyl, alkoxy, acyl, or aryl group. The PEG can be conjugated directly to the lipid or may be linked to the lipid via a linker moiety. Any linker moiety suitable for coupling the PEG to a lipid can be used including, e.g., non-ester containing linker moieties and ester-containing linker moieties. In a preferred embodiment, the linker moiety is a non-ester containing linker moiety. As used herein, the term “non-ester containing linker moiety” refers to a linker moiety that does not contain a carboxylic ester bond (—OC(O)—). Suitable non-ester containing linker moieties include, but are not limited to, amido (—C(O)NH—), amino (—NR—), carbonyl (—C(O)—), carbamate (— NHC(O)O—), urea (—NHC(O)NH—), disulphide (—S—S—), ether (—O—), succinyl (— (O)CCH 2 CH 2 C(O)—), succinamidyl (—NHC(O)CH 2 CH 2 C(O)NH—), ether, disulphide, as well as combinations thereof (such as a linker containing both a carbamate linker moiety and an amido linker moiety). In a preferred embodiment, a carbamate linker is used to couple the PEG to the lipid. In other embodiments, an ester containing linker moiety is used to couple the PEG to the lipid. Suitable ester containing linker moieties include, e.g., carbonate (—OC(O)O—), succinoyl, phosphate esters (—O—(O)POH—O—), sulfonate esters, and combinations thereof. Additional PEG-lipid conjugates suitable for use in the invention include, but are not limited to, compounds of formula: A-B-C or a salt thereof, wherein: A is (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl , (C 1 -C 6 )alkylthio , or (C 2 -C 6 )alkanoyloxy, wherein any (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 - C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is substituted with one or more anionic precursor groups, and wherein any (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 - C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is optionally substituted with one or more groups independently selected from the group consisting of halo, hydroxyl, (C 1 - C 3 )alkoxy, (C 1 -C 6 )alkanoyl, (C 1 -C 3 )alkoxycarbonyl , (C 1 -C 3 )alkylthio , or (C 2 -C 3 )alkanoyloxy; B is a polyethylene glycol chain having a molecular weight of from about 550 daltons to about 10,000 daltons; C is –L-R a ; L is selected from the group consisting of a direct bond, -C(O)O-, -C(O)NR b -, -NR b -, - C(O)-, -NR b C(O)O-, -NR b C(O)NR b -, -S-S-, -O-, -(O)CCH 2 CH 2 C(O)-, and -NHC(O)CH 2 CH 2 C(O)NH-; R a is a branched (C 10 -C 50 )alkyl or branched (C 10 -C 50 )alkenyl wherein one or more carbon atoms of the branched (C 10 -C 50 )alkyl or branched (C 10 -C 50 )alkenyl have been replaced with –O-; and each R b is independently H or (C 1 -C 6 )alkyl. The conjugated lipids may comprise a PEG-lipid including, e.g., a compound of formula A-PEG-diacylglycerol (DAG), A-PEG dialkyloxypropyl (DAA), A-PEG-phospholipid, A-PEG- ceramide (Cer), or mixtures thereof, wherein A is (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 - C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl , (C 1 -C 6 )alkylthio , or (C 2 -C 6 )alkanoyloxy, wherein any (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 - C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is substituted with one or more anionic precursor groups, and wherein any (C 1 -C 6 )alkyl, (C 3 - C 8 )cycloalkyl, (C 3 -C 8 )cycloalkyl(C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, (C 1 -C 6 )alkanoyl, (C 1 -C 6 )alkoxycarbonyl, (C 1 -C 6 )alkylthio, and (C 2 -C 6 )alkanoyloxy is optionally substituted with one or more groups independently selected from the group consisting of halo, hydroxyl, (C 1 -C 3 )alkoxy, (C 1 -C 6 )alkanoyl, (C 1 -C 3 )alkoxycarbonyl , (C 1 -C 3 )alkylthio , or (C 2 - C 3 )alkanoyloxy. The A-PEG-DAA conjugate may be A-PEG-dilauryloxypropyl (C12), A-PEG- dimyristyloxypropyl (C14), A-PEG-dipalmityloxypropyl (C16), or A-PEG-distearyloxypropyl (C18), or mixtures thereof. Phosphatidylethanolamines having a variety of acyl chain groups of varying chain lengths and degrees of saturation can be conjugated to PEG to form the lipid conjugate. Such phosphatidylethanolamines are commercially available, or can be isolated or synthesized using conventional techniques known to those of skilled in the art. Phosphatidylethanolamines containing saturated or unsaturated fatty acids with carbon chain lengths in the range of C 10 to C 20 are preferred. Phosphatidylethanolamines with mono- or diunsaturated fatty acids and mixtures of saturated and unsaturated fatty acids can also be used. Suitable phosphatidylethanolamines include, but are not limited to, dimyristoyl- phosphatidylethanolamine (DMPE), dipalmitoyl-phosphatidylethanolamine (DPPE), dioleoylphosphatidylethanolamine (DOPE), and distearoyl-phosphatidylethanolamine (DSPE). The term “ATTR” or “polyamide” refers to, without limitation, compounds described in U.S. Pat. Nos.6,320,017 and 6,586,559, the disclosures of which are herein incorporated by reference in their entirety for all purposes. These compounds include a compound having the formula: wherein R is a member selected from the group consisting of hydrogen, alkyl and acyl; R 1 is a member selected from the group consisting of hydrogen and alkyl; or optionally, R and R 1 and the nitrogen to which they are bound form an azido moiety; R 2 is a member of the group selected from hydrogen, optionally substituted alkyl, optionally substituted aryl and a side chain of an amino acid; R 3 is a member selected from the group consisting of hydrogen, halogen, hydroxy, alkoxy, mercapto, hydrazino, amino and NR 4 R 5 , wherein R 4 and R 5 are independently hydrogen or alkyl; n is 4 to 80; m is 2 to 6; p is 1 to 4; and q is 0 or 1. It will be apparent to those of skill in the art that other polyamides can be used in the compounds of the present invention. The term “diacylglycerol” refers to a compound having 2 fatty acyl chains, R 1 and R 2 , both of which have independently between 2 and 30 carbons bonded to the 1- and 2-position of glycerol by ester linkages. The acyl groups can be saturated or have varying degrees of unsaturation. Suitable acyl groups include, but are not limited to, lauryl (C 1 2), myristyl (C 1 4), palmityl (C 16 ), stearyl (C 18 ), and icosyl (C 20 ). In preferred embodiments, R 1 and R 2 are the same, i.e., R 1 and R 2 are both myristyl (i.e., dimyristyl), R 1 and R 2 are both stearyl (i.e., distearyl), etc. Diacylglycerols have the following general formula: The term “dialkyloxypropyl” refers to a compound having 2 alkyl chains, R 1 and R 2 , both of which have independently between 2 and 30 carbons. The alkyl groups can be saturated or have varying degrees of unsaturation. Dialkyloxypropyls have the following general formula: In a preferred embodiment, the PEG-lipid is a PEG-DAA conjugate having the following formula: wherein R 1 and R 2 are independently selected and are long-chain alkyl groups having from about 10 to about 22 carbon atoms; PEG is a polyethyleneglycol; and L is a non-ester containing linker moiety or an ester containing linker moiety as described above. The long-chain alkyl groups can be saturated or unsaturated. Suitable alkyl groups include, but are not limited to, lauryl (C 12 ), myristyl (C 14 ), palmityl (C 16 ), stearyl (C 18 ), and icosyl (C 20 ). In preferred embodiments, R 1 and R 2 are the same, i.e., R 1 and R 2 are both myristyl (i.e., dimyristyl), R 1 and R 2 are both stearyl (i.e., distearyl), etc. In Formula VII above, the PEG has an average molecular weight ranging from about 550 daltons to about 10,000 daltons. In certain instances, the PEG has an average molecular weight of from about 500 daltons to about 5,000 daltons (e.g., from about 1,000 daltons to about 5,000 daltons, from about 1,500 daltons to about 3,000 daltons, from about 750 daltons to about 3,000 daltons, from about 750 daltons to about 2,000 daltons, etc.). In preferred embodiments, the PEG has an average molecular weight of about 2,000 daltons or about 750 daltons. The PEG can be optionally substituted with alkyl, alkoxy, acyl, or aryl. In certain embodiments, the terminal hydroxyl group is substituted with a methoxy or methyl group. In a preferred embodiment, “L” is a non-ester containing linker moiety. Suitable non- ester containing linkers include, but are not limited to, an amido linker moiety, an amino linker moiety, a carbonyl linker moiety, a carbamate linker moiety, a urea linker moiety, an ether linker moiety, a disulphide linker moiety, a succinamidyl linker moiety, and combinations thereof. In a preferred embodiment, the non-ester containing linker moiety is a carbamate linker moiety (i.e., a PEG-C-DAA conjugate). In another preferred embodiment, the non-ester containing linker moiety is an amido linker moiety (i.e., a PEG-A-DAA conjugate). In yet another preferred embodiment, the non-ester containing linker moiety is a succinamidyl linker moiety (i.e., a PEG- S-DAA conjugate). In particular embodiments, the PEG-lipid conjugate is selected from: In one embodiment, n is selected so that the resulting polymer chain has a molecular weight of about 2000. The PEG-DAA conjugates are synthesized using standard techniques and reagents known to those of skill in the art. It will be recognized that the PEG-DAA conjugates will contain various amide, amine, ether, thio, carbamate, and urea linkages. Those of skill in the art will recognize that methods and reagents for forming these bonds are well known and readily available. See, e.g., March, ADVANCED ORGANIC CHEMISTRY (Wiley 1992); Larock, COMPREHENSIVE ORGANIC TRANSFORMATIONS (VCH 1989); and Furniss, VOGEL'S TEXTBOOK OF PRACTICAL ORGANIC CHEMISTRY, 5th ed. (Longman 1989). It will also be appreciated that any functional groups present may require protection and deprotection at different points in the synthesis of the PEG-DAA conjugates. Those of skill in the art will recognize that such techniques are well known. See, e.g., Green and Wuts, PROTECTIVE GROUPS IN ORGANIC SYNTHESIS (Wiley 1991). Preferably, the PEG-DAA conjugate is a dilauryloxypropyl (C 12 )-PEG conjugate, dimyristyloxypropyl (C 14 )-PEG conjugate, a dipalmityloxypropyl (C 16 )-PEG conjugate, or a distearyloxypropyl (C 18 )-PEG conjugate. Those of skill in the art will readily appreciate that other dialkyloxypropyls can be used in the PEG-DAA conjugates of the present invention. In addition to the foregoing, it will be readily apparent to those of skill in the art that other hydrophilic polymers can be used in place of PEG. Examples of suitable polymers that can be used in place of PEG include, but are not limited to, polyvinylpyrrolidone, polymethyloxazoline, polyethyloxazoline, polyhydroxypropyl methacrylamide, polymethacrylamide and polydimethylacrylamide, polylactic acid, polyglycolic acid, and derivatized celluloses such as hydroxymethylcellulose or hydroxyethylcellulose. The charges on the polycationic moieties can be either distributed around the entire particle moiety, or alternatively, they can be a discrete concentration of charge density in one particular area of the particle moiety e.g., a charge spike. If the charge density is distributed on the particle, the charge density can be equally distributed or unequally distributed. All variations of charge distribution of the polycationic moiety are encompassed by the present invention. In certain instances, the polycationic moiety can have a ligand attached, such as a targeting ligand or a chelating moiety for complexing calcium. Preferably, after the ligand is attached, the cationic moiety maintains a positive charge. In certain instances, the ligand that is attached has a positive charge. Suitable ligands include, but are not limited to, a compound or device with a reactive functional group and include lipids, amphipathic lipids, carrier compounds, bioaffinity compounds, biomaterials, biopolymers, biomedical devices, analytically detectable compounds, therapeutically active compounds, enzymes, peptides, proteins, antibodies, immune stimulators, radiolabels, fluorogens, biotin, drugs, haptens, DNA, RNA, polysaccharides, liposomes, virosomes, micelles, immunoglobulins, functional groups, other targeting moieties, or toxins. The lipid conjugate (e.g., PEG-lipid) typically comprises from about 0.1 mol % to about 10 mol %, from about 0.5 mol % to about 10 mol %, from about 1 mol % to about 10 mol %, from about 2 mol % to about 10 mol %, from about 2 mol % to about 8 mol %, from about 2 mol % to about 5 mol %, from about 2 mol % to about 4 mol %, from about 0.6 mol % to about 1.9 mol %, from about 0.7 mol % to about 1.8 mol %, from about 0.8 mol % to about 1.7 mol %, from about 0.9 mol % to about 1.6 mol %, from about 0.9 mol % to about 1.8 mol %, from about 1 mol % to about 1.8 mol %, from about 1 mol % to about 1.7 mol %, from about 1.2 mol % to about 1.8 mol %, from about 1.2 mol % to about 1.7 mol %, from about 1.3 mol % to about 1.6 mol %, or from about 1.4 mol % to about 1.5 mol % of the total lipid present in the particle. One of ordinary skill in the art will appreciate that the concentration of the lipid conjugate can be varied depending on the lipid conjugate employed and the rate at which the nucleic acid-lipid particle is to become fusogenic. By controlling the composition and concentration of the lipid conjugate, one can control the rate at which the lipid conjugate exchanges out of the nucleic acid-lipid particle and, in turn, the rate at which the nucleic acid-lipid particle becomes fusogenic. For instance, when a PEG- phosphatidylethanolamine conjugate or a PEG-ceramide conjugate is used as the lipid conjugate, the rate at which the nucleic acid-lipid particle becomes fusogenic can be varied, for example, by varying the concentration of the lipid conjugate, by varying the molecular weight of the PEG, or by varying the chain length and degree of saturation of the acyl chain groups on the phosphatidylethanolamine or the ceramide. In addition, other variables including, for example, pH, temperature, ionic strength, etc. can be used to vary and/or control the rate at which the nucleic acid-lipid particle becomes fusogenic. Other methods which can be used to control the rate at which the nucleic acid-lipid particle becomes fusogenic will become apparent to those of skill in the art upon reading this disclosure. Preparation of Lipid Particles The lipid particles of the present invention, e.g., LNP, in which an active agent or therapeutic agent such as a nucleic acid molecule is encapsulated in a lipid bilayer and is protected from degradation, can be formed by any method known in the art including, but not limited to, a continuous mixing method or a direct dilution process. In preferred embodiments, the non-cationic lipids are egg sphingomyelin (ESM), distearoylphosphatidylcholine (DSPC), dioleoylphosphatidylcholine (DOPC), 1-palmitoyl-2- oleoyl-phosphatidylcholine (POPC), dipalmitoyl-phosphatidylcholine (DPPC), monomethyl- phosphatidylethanolamine, dimethyl-phosphatidylethanolamine, 14:0 PE (1,2-dimyristoyl- phosphatidylethanolamine (DMPE)), 16:0 PE (1,2-dipalmitoyl-phosphatidylethanolamine (DPPE)), 18:0 PE (1,2-distearoyl-phosphatidylethanolamine (DSPE)), 18:1 PE (1,2-dioleoyl- phosphatidylethanolamine (DOPE)), 18:1 trans PE (1,2-dielaidoyl-phosphatidylethanolamine (DEPE)), 18:0-18:1 PE (1-stearoyl-2-oleoyl-phosphatidylethanolamine (SOPE)), 16:0-18:1 PE (1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE)), polyethylene glycol-based polymers (e.g., PEG 2000, PEG 5000, PEG-modified diacylglycerols, or PEG-modified dialkyloxypropyls), cholesterol, or combinations thereof. In certain embodiments, the present invention provides for LNP produced via a continuous mixing method, e.g., a process that includes providing an aqueous solution comprising a nucleic acid, such as an interfering RNA or mRNA, in a first reservoir, providing an organic lipid solution in a second reservoir, and mixing the aqueous solution with the organic lipid solution such that the organic lipid solution mixes with the aqueous solution so as to substantially instantaneously produce a liposome encapsulating the nucleic acid (e.g., interfering RNA or mRNA). This process and the apparatus for carrying this process are described in detail in U.S. Patent Publication No.20040142025, the disclosure of which is herein incorporated by reference in its entirety for all purposes. The action of continuously introducing lipid and buffer solutions into a mixing environment, such as in a mixing chamber, causes a continuous dilution of the lipid solution with the buffer solution, thereby producing a liposome substantially instantaneously upon mixing. As used herein, the phrase “continuously diluting a lipid solution with a buffer solution” (and variations) generally means that the lipid solution is diluted sufficiently rapidly in a hydration process with sufficient force to effectuate vesicle generation. By mixing the aqueous solution comprising a nucleic acid with the organic lipid solution, the organic lipid solution undergoes a continuous stepwise dilution in the presence of the buffer solution (i.e., aqueous solution) to produce a nucleic acid-lipid particle. The LNP formed using the continuous mixing method typically have a size of from about 40 nm to about 150 nm, from about 40 nm to about 80 nm, from about 40 nm to about 60 nm, from about 50 nm to about 60 nm, from about 50 nm to about 150 nm, from about 60 nm to about 130 nm, from about 70 nm to about 110 nm, or from about 70 nm to about 90 nm. The particles thus formed do not aggregate and are optionally sized to achieve a uniform particle size. In another embodiment, the present invention provides for LNP produced via a direct dilution process that includes forming a liposome solution and immediately and directly introducing the liposome solution into a collection vessel containing a controlled amount of dilution buffer. In preferred aspects, the collection vessel includes one or more elements configured to stir the contents of the collection vessel to facilitate dilution. In one aspect, the amount of dilution buffer present in the collection vessel is substantially equal to the volume of liposome solution introduced thereto. As a non-limiting example, a liposome solution in 45% ethanol when introduced into the collection vessel containing an equal volume of dilution buffer will advantageously yield smaller particles. In yet another embodiment, the present invention provides for LNP produced via a direct dilution process in which a third reservoir containing dilution buffer is fluidly coupled to a second mixing region. In this embodiment, the liposome solution formed in a first mixing region is immediately and directly mixed with dilution buffer in the second mixing region. In preferred aspects, the second mixing region includes a T-connector arranged so that the liposome solution and the dilution buffer flows meet as opposing 180° flows; however, connectors providing shallower angles can be used, e.g., from about 27° to about 180°. A pump mechanism delivers a controllable flow of buffer to the second mixing region. In one aspect, the flow rate of dilution buffer provided to the second mixing region is controlled to be substantially equal to the flow rate of liposome solution introduced thereto from the first mixing region. In another aspect, the flow rate of dilution buffer provided to the second mixing region is controlled to be substantially different to the flow rate of liposome solution introduced thereto from the first mixing region. This embodiment advantageously allows for more control of the flow of dilution buffer mixing with the liposome solution in the second mixing region, and therefore also the concentration of liposome solution in buffer throughout the second mixing process. Such control of the dilution buffer flow rate advantageously allows for small particle size formation at reduced concentrations. These processes and the apparatuses for carrying out these direct dilution processes are described in detail in U.S. Patent Publication No.20070042031, the disclosure of which is herein incorporated by reference in its entirety for all purposes. The LNP formed using the direct dilution process typically have a size of from about 40 nm to about 150 nm, from about 40 nm to about 80 nm, from about 40 nm to about 60 nm, from about 50 nm to about 60 nm, from about 50 nm to about 150 nm, from about 60 nm to about 130 nm, from about 70 nm to about 110 nm, or from about 70 nm to about 90 nm. The particles thus formed do not aggregate and are optionally sized to achieve a uniform particle size. If needed, the lipid particles of the invention (e.g., LNP) can be sized by any of the methods available for sizing liposomes. The sizing may be conducted in order to achieve a desired size range and relatively narrow distribution of particle sizes. Several techniques are available for sizing the particles to a desired size. One sizing method, used for liposomes and equally applicable to the present particles, is described in U.S. Pat. No.4,737,323, the disclosure of which is herein incorporated by reference in its entirety for all purposes. Sonicating a particle suspension either by bath or probe sonication produces a progressive size reduction down to particles of less than about 50 nm in size. Homogenization is another method which relies on shearing energy to fragment larger particles into smaller ones. In a typical homogenization procedure, particles are recirculated through a standard emulsion homogenizer until selected particle sizes, typically between about 60 and about 80 nm, are observed. In both methods, the particle size distribution can be monitored by conventional laser- beam particle size discrimination, or QELS. Extrusion of the particles through a small-pore polycarbonate membrane or an asymmetric ceramic membrane is also an effective method for reducing particle sizes to a relatively well-defined size distribution. Typically, the suspension is cycled through the membrane one or more times until the desired particle size distribution is achieved. The particles may be extruded through successively smaller-pore membranes, to achieve a gradual reduction in size. In some embodiments, the nucleic acids in the LNP are precondensed as described in, e.g., U.S. patent application Ser. No.09/744,103, the disclosure of which is herein incorporated by reference in its entirety for all purposes. In other embodiments, the methods will further comprise adding non-lipid polycations which are useful to effect the lipofection of cells using the present compositions. Examples of suitable non-lipid polycations include, hexadimethrine bromide (sold under the brandname POLYBRENE®, from Aldrich Chemical Co., Milwaukee, Wis., USA) or other salts of hexadimethrine. Other suitable polycations include, for example, salts of poly-L-ornithine, poly- L-arginine, poly-L-lysine, poly-D-lysine, polyallylamine, and polyethyleneimine. Addition of these salts is preferably after the particles have been formed. In some embodiments, the nucleic acid to lipid ratios (mass/mass ratios) in a formed LNP will range from about 0.01 to about 0.2, from about 0.02 to about 0.1, from about 0.03 to about 0.1, or from about 0.01 to about 0.08. The ratio of the starting materials also falls within this range. In other embodiments, the LNP preparation uses about 400 μg nucleic acid per 10 mg total lipid or a nucleic acid to lipid mass ratio of about 0.01 to about 0.08 and, more preferably, about 0.04, which corresponds to 1.25 mg of total lipid per 50 μg of nucleic acid. In other preferred embodiments, the particle has a nucleic acid:lipid mass ratio of about 0.08. In other embodiments, the lipid to nucleic acid ratios (mass/mass ratios) in a formed LNP will range from about 1 (1:1) to about 100 (100:1), from about 5 (5:1) to about 100 (100:1), from about 1 (1:1) to about 50 (50:1), from about 2 (2:1) to about 50 (50:1), from about 3 (3:1) to about 50 (50:1), from about 4 (4:1) to about 50 (50:1), from about 5 (5:1) to about 50 (50:1), from about 1 (1:1) to about 25 (25:1), from about 2 (2:1) to about 25 (25:1), from about 3 (3:1) to about 25 (25:1), from about 4 (4:1) to about 25 (25:1), from about 5 (5:1) to about 25 (25:1), from about 5 (5:1) to about 20 (20:1), from about 5 (5:1) to about 15 (15:1), from about 5 (5:1) to about 10 (10:1), about 5 (5:1), 6 (6:1), 7 (7:1), 8 (8:1), 9 (9:1), (10:1), 11 (11:1), 12 (12:1), 13 (13:1), 14 (14:1), 15 (15:1), 16 (16:1), 17 (17:1), 18 (18:1), 19 (19:1), 20 (20:1), 21 (21:1), 22 (22:1), 23 (23:1), 24 (24:1), 25 (25:1), 26 (26:1), 27 (27:1), 28 (28:1), 29 (29:1) or 30 (30:1). The ratio of the starting materials also typically falls within this range. As previously discussed, the conjugated lipid may further include a CPL. A variety of general methods for making LNP -CPLs (CPL-containing LNP) are discussed herein. Two general techniques include “post-insertion” technique, that is, insertion of a CPL into, for example, a pre-formed LNP, and the “standard” technique, wherein the CPL is included in the lipid mixture during, for example, the LNP formation steps. The post-insertion technique results in LNP having CPLs mainly in the external face of the LNP bilayer membrane, whereas standard techniques provide LNP having CPLs on both internal and external faces. The method is especially useful for vesicles made from phospholipids (which can contain cholesterol) and also for vesicles containing PEG-lipids (such as PEG-DAAs and PEG-DAGs). Methods of making LNP -CPL, are taught, for example, in U.S. Pat. Nos.5,705,385; 6,586,410; 5,981,501; 6,534,484; and 6,852,334; U.S. Patent Publication No.20020072121; and PCT Publication No. WO 00/62813, the disclosures of which are herein incorporated by reference in their entirety for all purposes. Other methods for generating LNP may be found, for example, in U.S. Patent No. 9,005,654 and PCT Publication No. WO 2007/012191, the disclosures of which are herein incorporated by reference in their entirety for all purposes. Kits The present invention also provides lipid particles (e.g., LNP) in kit form. The kit may comprise a container which is compartmentalized for holding the various elements of the lipid particles (e.g., the active agents or therapeutic agents such as nucleic acids and the individual lipid components of the particles). In some embodiments, the kit may further comprise an endosomal membrane destabilizer (e.g., calcium ions). The kit typically contains the lipid particle compositions of the present invention, preferably in dehydrated form, with instructions for their rehydration and administration. As explained herein, the lipid particles of the invention (e.g., LNP) can be tailored to preferentially target particular tissues, organs, or tumors of interest. In certain instances, preferential targeting of lipid particles such as LNP may be carried out by controlling the composition of the particle itself. For instance, as set forth in Example 11, it has been found that the 1:57 PEG-cDSA LNP formulation can be used to preferentially target tumors outside of the liver, whereas the 1:57 PEG-cDMA LNP formulation can be used to preferentially target the liver (including liver tumors). In certain other instances, it may be desirable to have a targeting moiety attached to the surface of the lipid particle to further enhance the targeting of the particle. Methods of attaching targeting moieties (e.g., antibodies, proteins, etc.) to lipids (such as those used in the present particles) are known to those of skill in the art. Administration of Lipid Particles Once formed, the lipid particles of the invention (e.g., LNP) are useful for the introduction of active agents or therapeutic agents (e.g., nucleic acids, such as interfering RNA or mRNA) into cells. Accordingly, the present invention also provides methods for introducing an active agent or therapeutic agent such as a nucleic acid (e.g., interfering RNA or mRNA) into a cell. The methods are carried out in vitro or in vivo by first forming the particles as described above and then contacting the particles with the cells for a period of time sufficient for delivery of the active agent or therapeutic agent to the cells to occur. The lipid particles of the invention (e.g., LNP) can be adsorbed to almost any cell type with which they are mixed or contacted. Once adsorbed, the particles can either be endocytosed by a portion of the cells, exchange lipids with cell membranes, or fuse with the cells. Transfer or incorporation of the active agent or therapeutic agent (e.g., nucleic acid) portion of the particle can take place via any one of these pathways. In particular, when fusion takes place, the particle membrane is integrated into the cell membrane and the contents of the particle combine with the intracellular fluid. The lipid particles of the invention (e.g., LNP) can be administered either alone or in a mixture with a pharmaceutically-acceptable carrier (e.g., physiological saline or phosphate buffer) selected in accordance with the route of administration and standard pharmaceutical practice. Generally, normal buffered saline (e.g., 135-150 mM NaCl) will be employed as the pharmaceutically-acceptable carrier. Other suitable carriers include, e.g., water, buffered water, 0.4% saline, 0.3% glycine, and the like, including glycoproteins for enhanced stability, such as albumin, lipoprotein, globulin, etc. Additional suitable carriers are described in, e.g., REMINGTON'S PHARMACEUTICAL SCIENCES, Mack Publishing Company, Philadelphia, Pa., 17th ed. (1985). As used herein, “carrier” includes any and all solvents, dispersion media, vehicles, coatings, diluents, antibacterial and antifungal agents, isotonic and absorption delaying agents, buffers, carrier solutions, suspensions, colloids, and the like. The phrase “pharmaceutically-acceptable” refers to molecular entities and compositions that do not produce an allergic or similar untoward reaction when administered to a human. The pharmaceutically-acceptable carrier is generally added following particle formation. Thus, after the particle is formed, the particle can be diluted into pharmaceutically-acceptable carriers such as normal buffered saline. The concentration of particles in the pharmaceutical formulations can vary widely, i.e., from less than about 0.05%, usually at or at least about 2 to 5%, to as much as about 10 to 90% by weight, and will be selected primarily by fluid volumes, viscosities, etc., in accordance with the particular mode of administration selected. For example, the concentration may be increased to lower the fluid load associated with treatment. This may be particularly desirable in patients having atherosclerosis-associated congestive heart failure or severe hypertension. Alternatively, particles composed of irritating lipids may be diluted to low concentrations to lessen inflammation at the site of administration. The pharmaceutical compositions of the present invention may be sterilized by conventional, well-known sterilization techniques. Aqueous solutions can be packaged for use or filtered under aseptic conditions and lyophilized, the lyophilized preparation being combined with a sterile aqueous solution prior to administration. The compositions can contain pharmaceutically-acceptable auxiliary substances as required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents and the like, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, and calcium chloride. Additionally, the particle suspension may include lipid-protective agents which protect lipids against free-radical and lipid-peroxidative damages on storage. Lipophilic free-radical quenchers, such as alphatocopherol and water-soluble iron-specific chelators, such as ferrioxamine, are suitable. In Vivo Administration Systemic delivery for in vivo therapy, e.g., delivery of a therapeutic nucleic acid to a distal target cell via body systems such as the circulation, has been achieved using nucleic acid- lipid particles such as those described in PCT Publication Nos. WO 05/007196, WO 05/121348, WO 05/120152, and WO 04/002453, the disclosures of which are herein incorporated by reference in their entirety for all purposes. The present invention also provides fully encapsulated lipid particles that protect the nucleic acid from nuclease degradation in serum, are nonimmunogenic, are small in size, and are suitable for repeat dosing. For in vivo administration, administration can be in any manner known in the art, e.g., by injection, oral administration, inhalation (e.g., intransal or intratracheal), transdermal application, or rectal administration. Administration can be accomplished via single or divided doses. The pharmaceutical compositions can be administered parenterally, i.e., intraarticularly, intravenously, intraperitoneally, subcutaneously, or intramuscularly. In some embodiments, the pharmaceutical compositions are administered intravenously or intraperitoneally by a bolus injection (see, e.g., U.S. Pat. No.5,286,634). Intracellular nucleic acid delivery has also been discussed in Straubringer et al., Methods Enzymol., 101:512 (1983); Mannino et al., Biotechniques, 6:682 (1988); Nicolau et al., Crit. Rev. Ther. Drug Carrier Syst., 6:239 (1989); and Behr, Acc. Chem. Res., 26:274 (1993). Still other methods of administering lipid-based therapeutics are described in, for example, U.S. Pat. Nos.3,993,754; 4,145,410; 4,235,871; 4,224,179; 4,522,803; and 4,588,578. The lipid particles can be administered by direct injection at the site of disease or by injection at a site distal from the site of disease (see, e.g., Culver, HUMAN GENE THERAPY, MaryAnn Liebert, Inc., Publishers, New York. pp.70-71 (1994)). The disclosures of the above-described references are herein incorporated by reference in their entirety for all purposes. The compositions of the present invention, either alone or in combination with other suitable components, can be made into aerosol formulations (i.e., they can be “nebulized”) to be administered via inhalation (e.g., intranasally or intratracheally) (see, Brigham et al., Am. J. Sci., 298:278 (1989)). Aerosol formulations can be placed into pressurized acceptable propellants, such as dichlorodifluoromethane, propane, nitrogen, and the like. In certain embodiments, the pharmaceutical compositions may be delivered by intranasal sprays, inhalation, and/or other aerosol delivery vehicles. Methods for delivering nucleic acid compositions directly to the lungs via nasal aerosol sprays have been described, e.g., in U.S. Pat. Nos.5,756,353 and 5,804,212. Likewise, the delivery of drugs using intranasal microparticle resins and lysophosphatidyl-glycerol compounds (U.S. Pat. No.5,725,871) are also well-known in the pharmaceutical arts. Similarly, transmucosal drug delivery in the form of a polytetrafluoroetheylene support matrix is described in U.S. Pat. No.5,780,045. The disclosures of the above-described patents are herein incorporated by reference in their entirety for all purposes. Formulations suitable for parenteral administration, such as, for example, by intraarticular (in the joints), intravenous, intramuscular, intradermal, intraperitoneal, and subcutaneous routes, include aqueous and non-aqueous, isotonic sterile injection solutions, which can contain antioxidants, buffers, bacteriostats, and solutes that render the formulation isotonic with the blood of the intended recipient, and aqueous and non-aqueous sterile suspensions that can include suspending agents, solubilizers, thickening agents, stabilizers, and preservatives. In the practice of this invention, compositions are preferably administered, for example, by intravenous infusion, orally, topically, intraperitoneally, intravesically, or intrathecally. Generally, when administered intravenously, the lipid particle formulations are formulated with a suitable pharmaceutical carrier. Many pharmaceutically acceptable carriers may be employed in the compositions and methods of the present invention. Suitable formulations for use in the present invention are found, for example, in REMINGTON'S PHARMACEUTICAL SCIENCES, Mack Publishing Company, Philadelphia, Pa., 17th ed. (1985). A variety of aqueous carriers may be used, for example, water, buffered water, 0.4% saline, 0.3% glycine, and the like, and may include glycoproteins for enhanced stability, such as albumin, lipoprotein, globulin, etc. Generally, normal buffered saline (135-150 mM NaCl) will be employed as the pharmaceutically acceptable carrier, but other suitable carriers will suffice. These compositions can be sterilized by conventional liposomal sterilization techniques, such as filtration. The compositions may contain pharmaceutically acceptable auxiliary substances as required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents and the like, for example, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, triethanolamine oleate, etc. These compositions can be sterilized using the techniques referred to above or, alternatively, they can be produced under sterile conditions. The resulting aqueous solutions may be packaged for use or filtered under aseptic conditions and lyophilized, the lyophilized preparation being combined with a sterile aqueous solution prior to administration. In certain applications, the lipid particles disclosed herein may be delivered via oral administration to the individual. The particles may be incorporated with excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, pills, lozenges, elixirs, mouthwash, suspensions, oral sprays, syrups, wafers, and the like (see, e.g., U.S. Pat. Nos. 5,641,515, 5,580,579, and 5,792,451, the disclosures of which are herein incorporated by reference in their entirety for all purposes). These oral dosage forms may also contain the following: binders, gelatin; excipients, lubricants, and/or flavoring agents. When the unit dosage form is a capsule, it may contain, in addition to the materials described above, a liquid carrier. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. Of course, any material used in preparing any unit dosage form should be pharmaceutically pure and substantially non-toxic in the amounts employed. Typically, these oral formulations may contain at least about 0.1% of the lipid particles or more, although the percentage of the particles may, of course, be varied and may conveniently be between about 1% or 2% and about 60% or 70% or more of the weight or volume of the total formulation. Naturally, the amount of particles in each therapeutically useful composition may be prepared is such a way that a suitable dosage will be obtained in any given unit dose of the compound. Factors such as solubility, bioavailability, biological half-life, route of administration, product shelf life, as well as other pharmacological considerations will be contemplated by one skilled in the art of preparing such pharmaceutical formulations, and as such, a variety of dosages and treatment regimens may be desirable. Formulations suitable for oral administration can consist of: (a) liquid solutions, such as an effective amount of a packaged therapeutic agent such as nucleic acid (e.g., interfering RNA or mRNA) suspended in diluents such as water, saline, or PEG 400; (b) capsules, sachets, or tablets, each containing a predetermined amount of a therapeutic agent such as nucleic acid (e.g., interfering RNA or mRNA), as liquids, solids, granules, or gelatin; (c) suspensions in an appropriate liquid; and (d) suitable emulsions. Tablet forms can include one or more of lactose, sucrose, mannitol, sorbitol, calcium phosphates, corn starch, potato starch, microcrystalline cellulose, gelatin, colloidal silicon dioxide, talc, magnesium stearate, stearic acid, and other excipients, colorants, fillers, binders, diluents, buffering agents, moistening agents, preservatives, flavoring agents, dyes, disintegrating agents, and pharmaceutically compatible carriers. Lozenge forms can comprise a therapeutic agent such as nucleic acid (e.g., interfering RNA or mRNA) in a flavor, e.g., sucrose, as well as pastilles comprising the therapeutic agent in an inert base, such as gelatin and glycerin or sucrose and acacia emulsions, gels, and the like containing, in addition to the therapeutic agent, carriers known in the art. In another example of their use, lipid particles can be incorporated into a broad range of topical dosage forms. For instance, a suspension containing nucleic acid-lipid particles such as LNP can be formulated and administered as gels, oils, emulsions, topical creams, pastes, ointments, lotions, foams, mousses, and the like. When preparing pharmaceutical preparations of the lipid particles of the invention, it is preferable to use quantities of the particles which have been purified to reduce or eliminate empty particles or particles with therapeutic agents such as nucleic acid associated with the external surface. The methods of the present invention may be practiced in a variety of hosts. Preferred hosts include mammalian species, such as primates (e.g., humans and chimpanzees as well as other nonhuman primates), canines, felines, equines, bovines, ovines, caprines, rodents (e.g., rats and mice), lagomorphs, and swine. The amount of particles administered will depend upon the ratio of therapeutic agent (e.g., nucleic acid) to lipid, the particular therapeutic agent (e.g., nucleic acid) used, the disease or disorder being treated, the age, weight, and condition of the patient, and the judgment of the clinician, but will generally be between about 0.01 and about 50 mg per kilogram of body weight, preferably between about 0.1 and about 5 mg/kg of body weight, or about 10 8 -10 10 particles per administration (e.g., injection). In Vitro Administration For in vitro applications, the delivery of therapeutic agents such as nucleic acids (e.g., interfering RNA or mRNA) can be to any cell grown in culture, whether of plant or animal origin, vertebrate or invertebrate, and of any tissue or type. In preferred embodiments, the cells are animal cells, more preferably mammalian cells, and most preferably human cells. Contact between the cells and the lipid particles, when carried out in vitro, takes place in a biologically compatible medium. The concentration of particles varies widely depending on the particular application, but is generally between about 1 μmol and about 10 mmol. Treatment of the cells with the lipid particles is generally carried out at physiological temperatures (about 37° C.) for periods of time of from about 1 to 48 hours, preferably of from about 2 to 4 hours. In one group of preferred embodiments, a lipid particle suspension is added to 60-80% confluent plated cells having a cell density of from about 10 3 to about 10 5 cells/ml, more preferably about 2×10 4 cells/ml. The concentration of the suspension added to the cells is preferably of from about 0.01 to 0.2 μg/ml, more preferably about 0.1 μg/ml. Using an Endosomal Release Parameter (ERP) assay, the delivery efficiency of the LNP or other lipid particle of the invention can be optimized. An ERP assay is described in detail in U.S. Patent Publication No.20030077829, the disclosure of which is herein incorporated by reference in its entirety for all purposes. More particularly, the purpose of an ERP assay is to distinguish the effect of various cationic lipids and helper lipid components of LNP based on their relative effect on binding/uptake or fusion with/destabilization of the endosomal membrane. This assay allows one to determine quantitatively how each component of the LNP or other lipid particle affects delivery efficiency, thereby optimizing the LNP or other lipid particle. Usually, an ERP assay measures expression of a reporter protein (e.g., luciferase, β- galactosidase, green fluorescent protein (GFP), etc.), and in some instances, a LNP formulation optimized for an expression plasmid will also be appropriate for encapsulating an interfering RNA or mRNA. In other instances, an ERP assay can be adapted to measure downregulation of transcription or translation of a target sequence in the presence or absence of an interfering RNA (e.g., siRNA). In other instances, an ERP assay can be adapted to measure the expression of a target protein in the presence or absence of an mRNA. By comparing the ERPs for each of the various LNP or other lipid particles, one can readily determine the optimized system, e.g., the LNP or other lipid particle that has the greatest uptake in the cell. Cells for Delivery of Lipid Particles The compositions and methods of the present invention are used to treat a wide variety of cell types, in vivo and in vitro. Suitable cells include, e.g., hematopoietic precursor (stem) cells, fibroblasts, keratinocytes, hepatocytes, endothelial cells, skeletal and smooth muscle cells, osteoblasts, neurons, quiescent lymphocytes, terminally differentiated cells, slow or noncycling primary cells, parenchymal cells, lymphoid cells, epithelial cells, bone cells, and the like. In preferred embodiments, an active agent or therapeutic agent such as one or more nucleic acid molecules (e.g, an interfering RNA (e.g., siRNA) or mRNA) is delivered to cancer cells such as, e.g., lung cancer cells, colon cancer cells, rectal cancer cells, anal cancer cells, bile duct cancer cells, small intestine cancer cells, stomach (gastric) cancer cells, esophageal cancer cells, gallbladder cancer cells, liver cancer cells, pancreatic cancer cells, appendix cancer cells, breast cancer cells, ovarian cancer cells, cervical cancer cells, prostate cancer cells, renal cancer cells, cancer cells of the central nervous system, glioblastoma tumor cells, skin cancer cells, lymphoma cells, choriocarcinoma tumor cells, head and neck cancer cells, osteogenic sarcoma tumor cells, and blood cancer cells. In vivo delivery of lipid particles such as LNP encapsulating one or more nucleic acid molecules (e.g., interfering RNA (e.g., siRNA) or mRNA) is suited for targeting cells of any cell type. The methods and compositions can be employed with cells of a wide variety of vertebrates, including mammals, such as, e.g, canines, felines, equines, bovines, ovines, caprines, rodents (e.g., mice, rats, and guinea pigs), lagomorphs, swine, and primates (e.g. monkeys, chimpanzees, and humans). To the extent that tissue culture of cells may be required, it is well-known in the art. For example, Freshney, Culture of Animal Cells, a Manual of Basic Technique, 3rd Ed., Wiley-Liss, New York (1994), Kuchler et al., Biochemical Methods in Cell Culture and Virology, Dowden, Hutchinson and Ross, Inc. (1977), and the references cited therein provide a general guide to the culture of cells. Cultured cell systems often will be in the form of monolayers of cells, although cell suspensions are also used. Detection of Lipid Particles In some embodiments, the lipid particles of the present invention (e.g., LNP) are detectable in the subject at about 1, 2, 3, 4, 5, 6, 7, 8 or more hours. In other embodiments, the lipid particles of the present invention (e.g., LNP) are detectable in the subject at about 8, 12, 24, 48, 60, 72, or 96 hours, or about 6, 8, 10, 12, 14, 16, 18, 19, 22, 24, 25, or 28 days after administration of the particles. The presence of the particles can be detected in the cells, tissues, or other biological samples from the subject. The particles may be detected, e.g., by direct detection of the particles, detection of a therapeutic nucleic acid, such as an interfering RNA (e.g., siRNA) sequence or mRNA sequence, detection of the target sequence of interest (i.e., by detecting expression or reduced expression of the sequence of interest), or a combination thereof. Detection of Particles Lipid particles of the invention such as LNP can be detected using any method known in the art. For example, a label can be coupled directly or indirectly to a component of the lipid particle using methods well-known in the art. A wide variety of labels can be used, with the choice of label depending on sensitivity required, ease of conjugation with the lipid particle component, stability requirements, and available instrumentation and disposal provisions. Suitable labels include, but are not limited to, spectral labels such as fluorescent dyes (e.g., fluorescein and derivatives, such as fluorescein isothiocyanate (FITC) and Oregon Green™; rhodamine and derivatives such Texas red, tetrarhodimine isothiocynate (TRITC), etc., digoxigenin, biotin, phycoerythrin, AMCA, CyDyes™, and the like; radiolabels such as 3 H, 125 I, 35 S, 14 C, 32 P, 33 P, etc.; enzymes such as horse radish peroxidase, alkaline phosphatase, etc.; spectral colorimetric labels such as colloidal gold or colored glass or plastic beads such as polystyrene, polypropylene, latex, etc. The label can be detected using any means known in the art. Detection of Nucleic Acids Nucleic acids (e.g., interfering RNA or mRNA) are detected and quantified herein by any of a number of means well-known to those of skill in the art. The detection of nucleic acids may proceed by well-known methods such as Southern analysis, Northern analysis, gel electrophoresis, PCR, radiolabeling, scintillation counting, and affinity chromatography. Additional analytic biochemical methods such as spectrophotometry, radiography, electrophoresis, capillary electrophoresis, high performance liquid chromatography (HPLC), thin layer chromatography (TLC), and hyperdiffusion chromatography may also be employed. The selection of a nucleic acid hybridization format is not critical. A variety of nucleic acid hybridization formats are known to those skilled in the art. For example, common formats include sandwich assays and competition or displacement assays. Hybridization techniques are generally described in, e.g., “Nucleic Acid Hybridization, A Practical Approach,” Eds. Hames and Higgins, IRL Press (1985). The sensitivity of the hybridization assays may be enhanced through use of a nucleic acid amplification system which multiplies the target nucleic acid being detected. In vitro amplification techniques suitable for amplifying sequences for use as molecular probes or for generating nucleic acid fragments for subsequent subcloning are known. Examples of techniques sufficient to direct persons of skill through such in vitro amplification methods, including the polymerase chain reaction (PCR) the ligase chain reaction (LCR), Qβ-replicase amplification and other RNA polymerase mediated techniques (e.g., NASBA™) are found in Sambrook et al., In Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press (2000); and Ausubel et al., SHORT PROTOCOLS IN MOLECULAR BIOLOGY, eds., Current Protocols, Greene Publishing Associates, Inc. and John Wiley & Sons, Inc. (2002); as well as U.S. Pat. No. 4,683,202; PCR Protocols, A Guide to Methods and Applications (Innis et al. eds.) Academic Press Inc. San Diego, Calif. (1990); Arnheim & Levinson (Oct.1, 1990), C&EN 36; The Journal Of NIH Research, 3:81 (1991); Kwoh et al., Proc. Natl. Acad. Sci. USA, 86:1173 (1989); Guatelli et al., Proc. Natl. Acad. Sci. USA, 87:1874 (1990); Lomell et al., J. Clin. Chem., 35:1826 (1989); Landegren et al., Science, 241:1077 (1988); Van Brunt, Biotechnology, 8:291 (1990); Wu and Wallace, Gene, 4:560 (1989); Barringer et al., Gene, 89:117 (1990); and Sooknanan and Malek, Biotechnology, 13:563 (1995). Improved methods of cloning in vitro amplified nucleic acids are described in U.S. Pat. No.5,426,039. Other methods described in the art are the nucleic acid sequence based amplification (NASBA™, Cangene, Mississauga, Ontario) and Qβ-replicase systems. These systems can be used to directly identify mutants where the PCR or LCR primers are designed to be extended or ligated only when a select sequence is present. Alternatively, the select sequences can be generally amplified using, for example, nonspecific PCR primers and the amplified target region later probed for a specific sequence indicative of a mutation. The disclosures of the above-described references are herein incorporated by reference in their entirety for all purposes. Nucleic acids for use as probes, e.g., in in vitro amplification methods, for use as gene probes, or as inhibitor components are typically synthesized chemically according to the solid phase phosphoramidite triester method described by Beaucage et al., Tetrahedron Letts., 22:18591862 (1981), e.g., using an automated synthesizer, as described in Needham VanDevanter et al., Nucleic Acids Res., 12:6159 (1984). Purification of polynucleotides, where necessary, is typically performed by either native acrylamide gel electrophoresis or by anion exchange HPLC as described in Pearson et al., J. Chrom., 255:137149 (1983). The sequence of the synthetic polynucleotides can be verified using the chemical degradation method of Maxam and Gilbert (1980) in Grossman and Moldave (eds.) Academic Press, New York, Methods in Enzymology, 65:499. An alternative means for determining the level of transcription is in situ hybridization. In situ hybridization assays are well-known and are generally described in Angerer et al., Methods Enzymol., 152:649 (1987). In an in situ hybridization assay, cells are fixed to a solid support, typically a glass slide. If DNA is to be probed, the cells are denatured with heat or alkali. The cells are then contacted with a hybridization solution at a moderate temperature to permit annealing of specific probes that are labeled. The probes are preferably labeled with radioisotopes or fluorescent reporters. Ionizable Lipids Ionizable cationic lipids are typically the major lipid component in lipid nanoparticles (LNP). They are designed to be charge-neutral at standard physiological pH (~7) but acquire a positive charge at lower (acidic) pH. This helps with nucleic acid payload encapsulation during the LNP formation, and intracellular delivery (the endosomal fusion step requires a positive charge on the ionizable lipid). Ionizable lipids such as MC3 (used in the FDA-approved siRNA-LNP product Onpattro) and 3D-P-DMA have demonstrated excellent activity and tolerability in a variety of applications. However, they are not rapidly metabolized, and take several weeks to clear from target tissues. This makes them less appealing for applications that require multiple doses, especially with short dose intervals and/or chronic indications. One way to achieve a more favorable profile is the inclusion of carboxylic ester groups in the hydrophobic domain of the lipid. Ester groups are subject to enzymatic breakdown in the body, and this has been reported to improve lipid clearance in target tissues (Maier et al 2013). However, the chemical structure immediately surrounding the esters must be considered, as this affects how effective the strategy is. ALC-0315, the ionizable lipid in BNT162b2 (also known as the Pfizer COVID vaccine), has carboxylic esters in its hydrophobic domain, but was found to metabolize at a similar rate to MC3 [ref: Comirnaty Assessment Report, European Medicines Agency]. Further, the esters must be incorporated while maintaining a favorable activity and tolerability profile. To this end, a series of ionizable cationic lipids incorporating ester functionality has been designed, synthesized, and evaluated in the following ways: • Formulability (particle size, polydispersity, payload encapsulation, pKa) • Potency (mouse liver expression model, delivering luciferase-encoding and OTC mRNA) • Tolerability (mouse immunestimulation model, cytokine readout) • Lipid clearance (mouse model – clearance from target tissue (liver)) The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters, which can be changed or modified to yield essentially the same results.
EXAMPLES Preparatory Example 1. Synthesis of heptadecan-9-ylidenehydrazine Step 1. Synthesis of 9-heptadecanol A Grignard reagent was prepared from 1-bromooctane (6 g, 31 mmol) and magnesium (808 mg, 33 mmol) in THF with stirring at 45˚C for 2 hr. The reaction was cooled to 10˚C and ethyl formate (2.6 mL, 32 mmol) in THF (5 mL) added dropwise. H 2 O (3 mL) and 6M HCl (8 mL) were added to dissolve residual magnesium. The reaction was partitioned between hexane and H 2 O. The organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was stirred in EtOH with KOH (1.6 g) solution in water (3 mL). The ethanol was removed in-vacuo and the residue partitioned between 6M HCl and hexane. The organics were washed with H 2 O and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude product was purified by automated flash chromatography (0- 20% EtOAc/Hex) to give 9-heptadecanol (3.2 g, 81.2 %). Step 2. Synthesis of 9-heptadecanone 9-Heptadecanol (3.2 g, 12.6 mmol) and PCC-SiO 2 (1:1) (16.3 g, 38 mmol) were stirred in DCM (100 mL) at RT for 16 hr. The reaction was filtered through silica eluting with EtOAc. The organics were concentrated in-vacuo and purified by automated flash chromatography (0-10% EtOAc/Hex) to give 9-heptadecanone (3.2 g, 99.6 %). Step 3. Synthesis of N'-(heptadecan-9-ylidene)tert-butoxycarbohydrazide tert-Butoxycarbohydrazide (195 mg, 1.47 mmol), 9-heptadecanone (750 mg, 2.9 mmol) and AcOH (cat) were stirred in MeOH (10 mL) at reflux for 15 hr. The reaction was concentrated in-vacuo and purified by automated flash chromatography (0-20% EtOAc/Hex) to give N'-(heptadecan-9-ylidene)tert-butoxycarbohydrazide (320 mg, 58.9 %). Step 4. Synthesis of heptadecan-9-ylidenehydrazine N'-(Heptadecan-9-ylidene)tert-butoxycarbohydrazide (320 mg, 0.9 mmol) was stirred in 25 % TFA in DCM (40 mL) at RT until the reaction was complete. The solvent was removed in- vacuo to give heptadecan-9-ylidenehydrazine (231 mg, 99.1 %) which was used without further purification. Preparatory Example 2. Synthesis of ((6Z,15Z)-henicosa-6,15-dien-11- ylidene)hydrazine ((6Z,15Z)-Henicosa-6,15-dien-11-ylidene)hydrazine was prepared using analogous methodology as described above. Preparatory Example 3. Synthesis of Heptadecan-9-ylhydrazine Step 1. Synthesis of give N'-(heptadecan-9-yl)tert-butoxycarbohydrazide tert-Butoxycarbohydrazide (412 mg, 3.1mmol), 9-heptadecanone (794 mg, 3.1 mmol), AcOH (0.75 mL, 3.2 mmol) and NaBH(OAc)3 (2.0 g, 9.4 mmol) were stirred in DCM (20 mL) at RT for 2 days and at 40˚C for a further 20 hr. The reaction was washed with sat NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-12% EtOAc/Hex) to give N'-(heptadecan-9- yl)tert-butoxycarbohydrazide (700 mg, 60.5 %). Step 2 Synthesis of heptadecan-9-ylhydrazine N'-(heptadecan-9-yl)tert-butoxycarbohydrazide (700 mg, 1.9 mmol) was stirred with 25% TFA in DCM (10 mL) at RT for 1.5 hr. The reaction was concentrated in-vacuo to give heptadecan-9-ylhydrazine (500 mg, 97.9 %) which was used without purification. Preparatory Example 4. Synthesis of ((6Z,15Z)-Henicosa-6,15-dien-11-yl)hydrazine ((6Z,15Z)-Henicosa-6,15-dien-11-yl)hydrazine was prepared using analogous methodology as described above Preparatory Example 5. Synthesis of 1,1-dioctylhydrazine Step 1 Synthesis of N',N'-dioctyltert-butoxycarbohydrazide Octanal (2.4 mL, 15.0 mmol), tert-butoxycarbohydrazide (1 g, 7.6 mmol) and AcOH (7.6 mmol) were stirred in dry MeOH under a nitrogen atmosphere at 75˚C for 1 hr. After cooling to RT NaBH3CN (1.9 g, 30.3 mmol) was added and the mixture stirred at RT for 15 hr. The solvent was removed in-vacuo, the residue taken up in EtOAc, washed with H2O and brine, dried (MgSO4), filtered and concentrated. The crude material was purified by automated flash chromatography (0-10% EtOAc/Hex) to give N',N'-dioctyltert-butoxycarbohydrazide (2.0 g, 74.3 %). Step 2 Synthesis of 1,1-dioctylhydrazine N',N'-Dioctyltert-butoxycarbohydrazide (1.1 g, 3.0 mmol) was stirred in 30% TFA in DCM (20 mL) at 0˚C until complete allowing to warm to RT. The solvent was removed in- vacuo to give 1,1-dioctylhydrazine (782 mg, Quant) which was used without purification. Preparatory Example 6. Synthesis of 1,1-di((Z)-Dec-4-en-1-yl)hydrazine 1,1-di((Z)-Dec-4-en-1-yl)hydrazine was prepared using analogous methodology Preparatory Example 7. General Method (a) For the Synthesis of Branched Alkyl Alcohols - Exemplified by the synthesis of 5-octyltridec-4-en-1-ol Step 1. Synthesis of 9-(4-bromobutyl)heptadecan-9-ol A Grignard reagent was prepared from Mg (2.6 g, 105 mmol) and 1-bromooctane (20.0 g, 105 mmol) in anhydrous Et 2 O (35 mL) with refluxing for 1 hr. The reaction was cooled, and a solution of ethyl 5-bromopentanoate (8.0 g, 38.3 mmol) in dry Et 2 O (25 mL) was added dropwise followed with refluxing for an additional 1 hr. The reaction was cooled to RT and poured into 100 mL satd. ice/NH4Cl solution. The aqueous portion was extracted with Et 2 O and the organics dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-20% EtOAc/Hex) to give 9-(4-bromobutyl)heptadecan- 9-ol (10.6 g, 70.7%). Step 2. Synthesis of 9-(4-bromobutylidene)heptadecane 9-(4-Bromobutyl)heptadecan-9-ol (10.6 g, 27.0mmol) and p-TsOH.H 2 O (93 mg, 0.54 mmol) were stirred under N 2 at 130˚C for 2 hr. The crude material was purified by automated flash chromatography (0-4% EtOAc/Hex) to give 9-(4-bromobutylidene)heptadecane (8.84 g, 87.5%). Step 3. Synthesis of 5-octyltridec-4-en-1-ol 9-(4-Bromobutylidene)heptadecane (8.84 g, 23.7 mmol), benzyl(chloro)triethylamine (540 mg, 2.4 mmol) and NaOAc (7.8 g, 94.7 mmol) were stirred in DMF (60 mL) at 70˚C for 20 hr. The reaction was poured into ice/water and extracted with Et 2 O. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was taken up in MeOH, KOH (18.6 g, 332 mmol) in H 2 O added and the reaction stirred for 30 min. MeOH was removed in- vacuo and the reaction partitioned between H 2 O and Et 2 O. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo and the crude material purified by automated flash chromatography (0-15% EtOAc/Hex) to give 5-octyltridec-4-en-1-ol (4.5 g, 60.8%). Step 4. Synthesis of 5-octyltridecan-1-ol 5-Octyltridec-4-en-1-ol (4.469 g, 14.39 mmol) was subjected to catalytic hydrogenation over Pd-C at RT in MeOH (50 mL) for 15 hr. The reaction was filtered and concentrated in- vacuo to give 5-octyltridecan-1-ol (3.5 g, 77.8%) which was used without further purification. The following compounds were prepared using analogous methodology as described above Preparatory Example 8. General Method (b) for the Synthesis Of Branched Alkyl Alcohols - Exemplified by the synthesis of 3-pentyloctan-1-ol Step 1. Synthesis of ethyl 3-pentyloct-2-enoate Triethyl phosphonoacetate (65.8 g, 294 mmol) was stirred in THF (220 mL) at -l0°C.1M LiHMDS in THF (294 mL, 294 mmol) was added dropwise and the reaction stirred at -10°C for 1 hr then 0°C for 1 hr.6-Undecanone (25 g, 147 mmol) was added and the reaction stirred at 45°C for 16 hr. The reaction was quenched with H2O, extracted with Et 2 O and washed with brine. The organics were dried (MgSO4) filtered and concentrated in-vacuo to give ethyl 3- pentyloct-2-enoate (43.5 g) which was used in the subsequent step without further processing. Step 2. Synthesis of ethyl 3-pentyloctanoate Ethyl 3-pentyloct-2-enoate (35 g, 147 mmol) was subjected to catalytic hydrogenation over Pd-C in MeOH (100 mL) at RT for 20 hr. The reaction was filtered and concentrated in- vacuo to give ethyl 3-pentyloctanoate (33.3 g, 93.6 %) which was used without further purification. Step 3. Synthesis of 3-pentyloctan-1-ol LiAlH4 (6.8 g, 179 mmol) was stirred in THF (500 mL) at 0˚C for 30 min. Ethyl 3- pentyloctanoate (33.3 g, 138 mmol in THF (500 mL) was added dropwise and the reaction stirred at RT until complete. The reaction was cooled to 0˚C, diluted with Et 2 O (500mL) and quenched with 1M NaOH (16 mL). The reaction was stirred for 30 mins, dried (MgSO 4 ), filtered through celite and concentrated in-vacuo. The crude was purified by automated flash chromatography (0-30% EtOAc/Hex) to give 3-pentyloctan-1-ol (24.7 g, 89.7%). The following compounds were prepared using analogous methodology as described above: Preparatory Example 9. Synthesis of (3,5-dihexylphenyl)methanol Step 1. Synthesis of methyl 3,5-bis(hex-1-yn-1-yl)benzoate Methyl 3,5-dibromobenzoate (7.4 g, 25.0 mmol), hexyne (8.2 g, 100.0 mmol), dichlorobis[4-(diphenylphosphanyl)phenyl]palladium (1.4 g, 2.0 mmol), CuI (0.2 g, 1.0 mmol) and TEA (21.0 mL, 150 mmol) were stirred in benzene (100 mL) at 80˚C for 48 hr. The reaction was filtered through a silica pad eluting with EtOAc. The organics were concentrated in-vacuo and the crude purified by automated flash chromatography (0-20% EtOAc/Hex) to give methyl 3,5-bis(hex-1-yn-1-yl)benzoate (7.0 g, 94.4%). Step 2. Synthesis of methyl 3,5-dihexylbenzoate Methyl 3,5-bis(hex-1-yn-1-yl)benzoate (7.0 g, 23.6 mmol) was subjected to catalytic hydrogenation over Pd-C in EtOH (100 mL) at RT for 18 hr. The reaction was filtered through Celite and concentrated in-vacuo to give methyl 3,5-dihexylbenzoate (6.3 g, 87.7 %) which was used without further purification. Step 3. Synthesis of (3,5-dihexylphenyl)methanol Methyl 3,5-dihexylbenzoate (6.3 g, 20.7 mmol) was stirred in dry THF at 0˚C. LiAlH4 (1.2 g, 31.0 mmol) was added in portions and the reaction stirred for 1hr allowing to warm to RT. After completion the reaction was quenched with H 2 O and 1M NaOH and extracted with EtOAc. The organics were dried (MgSO 4 ), filtered, concentrated in-vacuo and purified by automated flash chromatography (10 % EtOAc/Hex) to give (3,5-dihexylphenyl)methanol (3.0 g, 52.4%). Preparatory Example 10. Synthesis of 2-fluoro-2-hexyldecanoic acid Step 1. Synthesis of ethyl 2-hexyldecanoate Hexyldecanoic acid (3 g, 11.7 mmol) and H 2 SO 4 (cat) were refluxed in EtOH (20 mL) for 15 hr. The reaction was concentrated in-vacuo and the residue partitioned between hexane and water. The organics were dried (MgSO 4 ), filtered, concentrated in-vacuo and the residue purified by automated flash chromatography (0-6% EtOAc/Hex) to give ethyl 2-hexyldecanoate (3.0 g, 90.7%). Step 2. Synthesis of ethyl 2-fluoro-2-hexyldecanoate Ethyl 2-hexyldecanoate (1 g, 3.5 mmol) in THF was added dropwise to a solution of LDA (2.6 mL, 2 M, 5.273 mmol) at -78 °C and stirred for 0.5 hr. N- fluorobenzenesulfonimide (1.7 g, 5.3 mmol,) in THF (15 mL) was added dropwise and the reaction was stirred for 18 hr allowing to warm to RT. The reaction was diluted with EtOAc, washed sequentially with aq. satd. NH4Cl, water and brine, dried (MgSO4), concentrated in- vacuo and purified by automated flash chromatography (0-6% EtOAc/Hex). NMR showed 60% conversion. The reaction was repeated a second time to give ethyl 2-fluoro-2-hexyldecanoate (770 mg, 72.4 %). Step 3. Synthesis of 2-fluoro-2-hexyldecanoic acid Ethyl 2-fluoro-2-hexyldecanoate (770 mg, 2.5 mmol) and LiOH (125 mg, 5.2 mmol) were stirred in MeOH (10 mL) and H 2 O (2 mL) at RT for 15 hr.6 M HCl (0.87 mL) was added and the MeOH removed in-vacuo. The residue was dissolved in DCM, washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 2-fluoro-2- hexyldecanoic acid (520 mg, 74.4 %). Preparatory Example 11. Synthesis of Amino Alcohol THP Ethers Exemplified by the Synthesis of 5-(Oxan-2-yloxy)pentan-1-amine Step 1. Synthesis of benzyl N-(5-hydroxypentyl)carbamate 5-Aminopentanol (21.0 g, 203 mmol) and benzyl 2,5-dioxopyrrolidin-1-yl carbonate (50.7 g, 203 mmol) were stirred in THF at RT for 16 hr. The reaction was concentrated in- vacuo, the residue taken up in EtOAc (250 mL), washed with 1M HCl and 0.5M NaOH, dried (MgSO 4 ), filtered and concentrated in-vacuo. The resultant oil was agitated in hexane until the product crystalized. The solid was recovered by filtration to give benzyl N-(5- hydroxypentyl)carbamate (44 g, 91.0%). Step 2. Synthesis of benzyl N-[5-(oxan-2-yloxy)pentyl]carbamate Benzyl N-(5-hydroxypentyl)carbamate (20.0 g, 84 mmol), 2H-pyran,3,4-dihydro- (8.6 g, 101) and pTsOH-H 2 O (1.6 g, 8.4 mmol) were stirred in DCM (270 mL) at RT for 2 hr. The reaction was washed with NaHCO 3 (sat. soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (10- 50 % EtOAc/Hex) to give benzyl N-[5-(oxan-2-yloxy)pentyl]carbamate (19.5 g, 72.0 %). Step 3. Synthesis of 5-(oxan-2-yloxy)pentan-1-amine Benzyl N-[5-(oxan-2-yloxy)pentyl]carbamate (19.0 g, 59 mmol) was subjected to catalytic hydrogenation over Pd/C in MeOH at RT for 16 hr. The reaction was filtered through Celite and concentrated in-vacuo to give 5-(oxan-2-yloxy)pentan-1-amine (10.9 g, 98.5%) which was used without purification. The following compound was prepared using analogous methodology as described above: 5-((Tetrahydro-2H-pyran-2-yl)oxy)pentan-1-amine Preparatory Example 12. Synthesis of Keto-THP Ethers Exemplified by the Synthesis of 1-(Oxan-2-yloxy)hexadecan-7-one Step 1. Synthesis of 2-[(6-bromohexyl)oxy]oxane 6-Bromo-1-hexanol (40 g, 220 mmol), dihydropyran (23 g, 265 mmol) and pTsOH-H 2 O (4.2 g, 22.0 mmol) were stirred in DCM (500 mL) at RT for 2hr. The reaction was washed with NaHCO 3 (sat. soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by flash chromatography (0-20% EtOAc/Hex) to give 2-[(6- bromohexyl)oxy]oxane (49 g, 83.6 %). Step 2. Synthesis of 1-(oxan-2-yloxy)hexadecan-7-ol A Grignard reagent was prepared from 2-[(6-bromohexyl)oxy]oxane (49 g, 185 mmol) and magnesium (5.4 g, 222 mmol) in anhydrous THF (175 mL) with refluxing for 30 mins. The reaction was cooled to 0˚C and decanal (23 g, 148 mmol) in anhydrous THF (144 mL) added dropwise over 1hr. The reaction was stirred for 2 hr allowing to warm to RT then quenched with sat'd NH 4 Cl solution. The organics were separated, washed with water and brine and dried (MgSO 4 ). The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% EtOAc/Hex) to give 1-(oxan-2-yloxy)hexadecan-7-ol (47 g, 92.8 %). Step 3. Synthesis of 1-(oxan-2-yloxy)hexadecan-7-one 1-(Oxan-2-yloxy)hexadecan-7-ol (47 g, 137 mmol) and PCC/SiO2 (1:1) (118 g, 274 mmol) were stirred in DCM (294 mL) at RT for 16 hr. The mixture was filtered through a pad of silica and eluted with 50:50 EtOAc/Hex. The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-10% EtOAc/Hex) to give 1-(oxan-2- yloxy)hexadecan-7-one (37.5 g, 80.3 %). Preparatory Example 13. Synthesis of Oxo-alkenes Exemplified by the Synthesis of Heptadec-1-en-7-one Step 1. Synthesis of heptadec-1-en-7-ol A Grignard reagent was prepared from 6-bromohex-1-ene (35 g, 215 mmol) and magnesium (6.3 g, 258 mmol) in THF (250 mL). After the initial reflux the reaction was stirred for 2 hours then cooled to 0˚C Undecanal (29 g, 172 mmol) was added dropwise and the reaction stirred at RT for 16 hr. The reaction was quenched with water (100 mL), cooled to 0˚C and 6M HCl (50mL) added to dissolve residual magnesium. The solution was diluted with Et 2 O (250 mL), the organics separated, washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo to give heptadec-1-en-7-ol (43 g, 98.4 %) which was used without further purification. Step 2. Synthesis of heptadec-1-en-7-one Heptadec-1-en-7-ol (43 g, 169 mmol) and PCC/Silica 1:1 wt (91 g, 211 mmol) were stirred in DCM (300 mL) at RT for 16 hr. The reaction was filtered through silica, eluting with DCM and the filtrate concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% EtOAc/hexane) to give heptadec-1-en-7-one (31 g, 72.7 %). Preparatory Example 14. Synthesis of Oxo-carboxylic Acids. Method (a) Exemplified by the Synthesis of 8-Oxooctadecanoic Acid Step 1 Synthesis of 2-[(7-bromoheptyl)oxy]oxane 7-Bromoheptan-1-ol (102 g, 523 mmol), dihydropyran (53 g, 627 mmol) and pTsOH- H 2 O (10 g, 52 mmol) were stirred in DCM (1370 mL for 2 hr. The reaction was washed with NaHCO 3 (sat soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was passed through silica pad with 25% EtOAc/Hex and the combined organics concentrated in-vacuo to give 2-[(7-bromoheptyl)oxy]oxane (135 g, 92.5 %) which was used without further purification. Step 2 Synthesis of 1-(oxan-2-yloxy)octadecan-8-ol A Grignard reagent was prepared from 2-[(7-bromoheptyl)oxy]oxane (135 g, 483 mmol) and magnesium (14.1 g, 580 mmol) in anhydrous THF (82 mL). After addition of the bromide the reaction was stirred at reflux for 30 min. The reaction was cooled to 0˚C and Undecanal (66 g, 387 mmol) in anhydrous THF (412 mL) added dropwise over 1 hr. The reaction was stirred for 16 hr allowing to warm to RT then quenched with H 2 O (100 mL) followed by 6M HCl (200 mL). The reaction was extracted with EtOAc, washed with H 2 O and brine, dried (MgSO 4 ) and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-50% EtOAc/Hex) to give 1-(oxan-2-yloxy)octadecan-8-ol (68 g, 47.0%) . Step 3 Synthesis of 8-oxooctadecanoic acid Periodic acid (239 g, 1009 mmol) and CrO 3 (0.5 g, 2.6 mol%) were dissolved in MeCN (3 L, 0.75% H 2 O V/V) at RT for 16 hr.1-(oxan-2-yloxy)octadecan-8-ol (68 g, 183 mmol) in MeCN (1 L, 0.75 v % water) was added over 30-60 mins while maintaining the reaction temp at 0-5˚C. The reaction was stirred for 16 hr allowing to warm to RT. Na2HPO 4 (163 g in 2.7 L H 2 O) was added to quench and the reaction extracted with EtOAc. The organics were washed sequentially with brine, NaHSO 3 aq. (29.91 g in 680 mL H 2 O) and brine. The reaction was dried (MgSO 4 ), filtered and concentrated in-vacuo. The residual solid was triturated in a minimum volume of MeCN to give 8-oxooctadecanoic acid (40.9 g, 74.7 %). Preparatory Example 15. Synthesis of Oxo-carboxylic Acids. Method (b) Exemplified by the Synthesis of 8-Oxooctadecanoic Acid Step 1. Synthesis of 1-decylcyclooctan-1-ol Bromo(decyl)magnesium (22.2 g, 90.4 mmol) was stirred at 10˚C in THF (150 mL). Cyclooctanone (9.3 g, 72 mmol) in THF (50mL) was added dropwise. After complete addition the reaction was cooled to 0˚C and quenched with water (100mL) and 6M HCl (400mL). The organics were separated, washed with brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography (0-10% EtOAc- hexane) to give 1-decylcyclooctan-1-ol (14.2 g, 73.1%). Step 2. Synthesis of (Z)-1-decylcyclooct-1-ene 1-Decylcyclooctan-1-ol (7.71 g, 28.8) and DMAP (7.0 g, 57.4 mmol) were stirred in DCM (77.1 mL) at 0˚C. Triphosgene (4.3 g, 14.4 mmol) in DCM (40 mL) was added dropwise. The reaction was stirred for 3 hr allowing to warm to RT then quenched with 2M HCl. The organics were separated, washed with brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography (100% hexane) to give (Z)-1-decylcyclooct-1-ene (7.2 g, 76.5 %). Step 3. Synthesis of 8-oxooctadecanoic acid (1Z)-1-Decylcyclooct-1-ene (5.5 g, 22 mmol) was stirred in acetone (55 mL) and H 2 O (5.5 mL) at 0˚C. KMnO 4 (17.4 g, 110 mmol) was added in portions over 4 hr while maintaining the temperature at 0˚C. The reaction was stirred for 18 hr allowing to warm to RT, then quenched with alternate addition of sodium bisulfite and 6 M HCl. The reaction was partitioned between 1M HCl and EtOAc and the combined organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (5-30% EtOAc-hexane) to give 8-oxooctadecanoic acid (3.7 g, 56.0%). The following compounds were prepared using analogous methodology as described above: 6-Oxohexadecanoic acid 9-Oxononadecanoic acid Preparatory Example 16. Synthesis of Oxo Esters Exemplified by the Synthesis of 2- Butyloctyl 8-Oxooctadecanoate 8-Oxooctadecanoic acid (1 g, 3.4 mmol), butyloctanol (687 mg, 3.7 mmol), DCC (1.4 g, 6.7 mmol) and DMAP (20 mg, 0.17 mmol) were stirred in DCM at RT for 1.5 hr. The reaction was concentrated in-vacuo, the residue suspended in hexanes and filtered. The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-25 % EtOAc/Hex) to give 2-butyloctyl 8-oxooctadecanoate (1.1 g, 68.9 %). The following compounds were prepared using analogous methodology described above
Preparatory Example 17. Synthesis of 8-[(2-Butyloctyl)oxy]-8-Oxooctanoic Acid Suberic acid (5 g, 28.7 mmol), butyloctanol (5.4 g, 28.7 mmol), EDC (5.8 g, 30.1 mmol), DIPEA (10 mL, 57.4 mmol) and DMAP (cat.) were stirred DCM (10 mL) and 1,4 dioxane (180 mL) at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in DCM, washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (5-30% EtOAc- hexane) to give 8-[(2-butyloctyl)oxy]-8-oxooctanoic acid (4.4 g, 45.0 %). The following compounds were prepared using analogous methods as described above 6-((2-Butyloctyl)oxy)-6-oxohexanoic acid 8-Oxo-8-(undecan-3-yloxy)octanoic acid 8-(Decyloxy)-8-oxooctanoic acid 8-Oxo-8-((3-pentyloctyl)oxy)octanoic acid 8-((3-Hexylnonyl)oxy)-8-oxooctanoic acid 9-((2-Butyloctyl)oxy)-9-oxononanoic acid 10-((2-Butyloctyl)oxy)-10-oxodecanoic acid 8-((3,5-Dihexylbenzyl)oxy)-8-oxooctanoic acid Preparatory Example 18. Synthesis of 3,5-Dihexylbenzyl 8-Aminooctanoate Step 1. Synthesis of (3,5-dihexylphenyl)methyl 8-[(tert-butoxycarbonyl)amino]octanoate (3,5-Dihexylphenyl)methanol (3.0 g, 10.9 mmol), 8-[(tert-butoxycarbonyl)- amino]octanoic acid (2.8 g, 10.9 mmol), DCC (2.5 g, 11.9 mmol), DIPEA (3.8 mL, 21.7 mmol) and DMAP (133 mg, 1.1 mmol) were stirred in DCM at RT for 16 hr. The resultant precipitate was removed by filtration, the filtrate concentrated in-vacuo and the residue purified by automated flash chromatography (10% EtOAc/Hex) to give (3,5-dihexylphenyl)methyl 8-[(tert- butoxycarbonyl)amino]octanoate (1.81 g, 32.2%). Step 2. Synthesis of (3,5-dihexylphenyl)methyl 8-aminooctanoate (3,5-Dihexylphenyl)methyl 8-[(tert-butoxycarbonyl)amino]octanoate (1.8 g, 3.5 mmol) was stirred in 20% TFA solution at RT in DCM for 1 hr. The reaction was concentrated in- vacuo, the residue taken up in DCM and converted to the free base with 1M NaOH. The organics were separated, dried (MgSO 4 ) and concentrated in-vacuo to give (3,5- dihexylphenyl)methyl 8-aminooctanoate (1.35 g, 93.0 %) which was used without purification. Preparatory Example 19. Synthesis of 2-Hexyldecyl 8-Aminooctanoate Step 1. Synthesis of 8-{[(benzyloxy)carbonyl]amino}octanoic acid 8-Aminooctanoic acid (5 g, 31.4 mmol), K2CO 3 (8.7 g, 63 mmol) and benzyl chloroformate (7.0 mL, 47.1 mmol) were stirred in THF (150 mL) at RT for 16 hr. The reaction was acidified (6M HCl) and concentrated in-vacuo. The residue was partitioned between DCM (100 mL) and H 2 O water (100 mL) and the aqueous extracted with DCM. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 8- {[(benzyloxy)carbonyl]amino}octanoic acid (8.4 g, 91.2 %) which was used without purification. Step 2. Synthesis of 2-hexyldecyl 8-{[(benzyloxy)carbonyl]amino}octanoate 8-{[(Benzyloxy)carbonyl]amino}octanoic acid (1.05 g, 3.6 mmol), EDC.HCl (1.4 g, 7.2 mmol), hexyldecanol (1.0 g, 4.0 mmol), DMAP (22 mg, 0.18 mmol) and DIPEA (1.9 mL, 10.7 mmol) were stirred in DCM (25 mL) at RT for 16 hr. The reaction was concentrated in- vacuo, taken up in EtOAc (100 mL), washed with saturated NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-50% EtOAc/hexanes) to give 2-hexyldecyl 8-{[(benzyloxy)carbonyl]amino}octanoate (1.45 g, 64.5 %). Step 3. Synthesis of 2-hexyldecyl 8-aminooctanoate 2-Hexyldecyl 8-{[(benzyloxy)carbonyl]amino}octanoate (1 g, 1.9 mmol) was subjected to catalytic hydrogenation over 10 % Palladium on Carbon (100 mg) in MeOH (25 mL) at RT for 16 hr. The reaction was filtered through celite and concentrated in-vacuo to give 2- hexyldecyl 8-aminooctanoate (0.71 g, 95.8 %). The following compounds were prepared using analogous methodology as described above.
Example 1. Synthesis of 2-Hexyldecyl 8-(N-decyl-4-(dimethylamino)butanamido)- octadecanoate (1) Step 1. Synthesis of 2-hexyldecyl 8-oxooctadecanoate 8-Oxooctadecanoic acid (1 g, 3.4 mmol), hexyldecanol (894 mg, 3.7 mmol), EDC (1.29 g, 6.7 mmol), DIPEA (1.8 mL, 10.1 mmol) and DMAP (cat.) were stirred in DCM (30 mL) at RT for 18 hr. The reaction was diluted with DCM, washed with NaHCO 3 (sat) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% EtOAc-hexane) to give 2-hexyldecyl 8- oxooctadecanoate (1.33 g, 75.9 %). Step 2. Synthesis of 2-hexyldecyl 8-(decylamino)octadecenoate 2-Hexyldecyl 8-oxooctadecanoate (933 mg, 1.8 mmol), N-decylamine (0.3 g, 1.9 mmol), NaCNBH3 (340 mg, 5.4 mmol) and AcOH (0.2 g, 3.6 mmol) were heated in MeOH (10 ml) at 50˚C for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in DCM and washed with NaHCO 3 (sat) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-5% MeOH-DCM) to give 2- hexyldecyl 8-(decylamino)octadecenoate (447 mg, 37.7 %). Step 3. Synthesis of 2-hexyldecyl 8-[N-decyl-4-(dimethylamino)butanamido]- octadecenoate (1) 4-Dimethylaminobutanoic acid (HCl) (0.38 g, 2.2 mmol), DCC (0.51 g, 2.5 mmol) and DMAP (0.41 g, 3.4 mmol) were stirred in MeCN (6 mL) at RT for 3 hr. A solution 2-hexyldecyl 8-(decylamino)octadecanoate (744 mg, 1.1 mmol) in DCM (8 mL) was added and the reaction stirred at RT for 18 hr. The reaction was concentrated, dispersed in hexane:EtOAc:TEA (75:25:1), filtered through Celite and the filtrate concentrated in-vacuo. The residue was purified by automated chromatography (0-10% MeOH-DCM) to give 2-hexyldecyl 8-[N-decyl-4-(dimethylamino)butanamido]octadecanoate (1) (230 mg, 26.4%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.01 – 3.92 (m, 2H), 3.63 (s, 1H), 3.10 – 2.97 (m, 2H), 2.31 (h, J = 6.6 Hz, 6H), 2.22 (s, 6H), 1.82 (q, J = 7.7 Hz, 2H), 1.48 (d, J = 36.9 Hz, 10H), 1.27 (s, 58H), 0.88 (t, J = 6.6 Hz, 12H). The following compounds were prepared using analogous methods as described above 2-Hexyldecyl 6-(N-decyl-4-(dimethylamino)butanamido)hexadecanoate (2). 1 H NMR (400 MHz, CDCl 3 ) δ 3.95 (d, J = 5.7 Hz, 2H), 3.65 (s, 1H), 3.09 – 2.98 (m, 2H), 2.31 (dt, J = 15.3, 7.4 Hz, 6H), 2.21 (s, 6H), 1.82 (q, J = 7.7 Hz, 2H), 1.48 (d, J = 29.4 Hz, 10H), 1.27 (s, 54H), 0.88 (t, J = 6.7 Hz, 12H). 2-Hexyldecyl 7-(N-decyl-5-(dimethylamino)pentanamido)heptadecanoate (3). NMR (400 MHz, CDCl 3 ) δ 3.98 (dd, J = 5.8, 3.9 Hz, 2H), 3.70 – 3.57 (m, 1H), 3.04 (s, 2H), 2.31 (dtt, J = 7.5, 5.8, 3.0 Hz, 6H), 2.24 (s, 6H), 1.75 – 1.40 (m, 17H), 1.28 (p, J = 5.4 Hz, 55H), 0.90 (td, J = 6.8, 2.1 Hz, 12H). 2-Hexyldecyl 7-(N-decyl-4-(dimethylamino)butanamido)heptadecanoate (4). 1 H NMR (400 MHz, CDCl 3 ) δ 3.98 (dd, J = 5.8, 4.1 Hz, 2H), 3.72 – 3.60 (m, 1H), 3.06 (q, J = 7.7 Hz, 2H), 2.39 – 2.27 (m, 6H), 2.24 (d, J = 1.1 Hz, 6H), 1.85 (h, J = 7.4 Hz, 2H), 1.72 – 1.40 (m, 13H), 1.29 (dq, J = 10.3, 6.5 Hz, 55H), 0.90 (td, J = 6.8, 2.3 Hz, 12H). Tridecan-7-yl 9-(N-decyl-4-(dimethylamino)butanamido)nonadecanoate (5). 1 H NMR (400 MHz, CDCl 3 ) δ 4.88 (q, J = 6.4 Hz, 1H), 3.66 (t, J = 7.1 Hz, 1H), 3.06 (q, J = 6.7 Hz, 2H), 2.39 – 2.25 (m, 6H), 2.24 (s, 6H), 1.84 (h, J = 7.6 Hz, 2H), 1.72 – 1.40 (m, 17H), 1.29 (d, J = 8.9 Hz, 57H), 0.90 (t, J = 6.4 Hz, 12H). 3-Pentyloctyl 3-(N-decyl-4-(dimethylamino)butanamido)dodecanoate (6). 1 H NMR (400 MHz, CDCl 3 ) δ 4.37 – 4.16 (m, 1H), 4.08 (q, J = 7.1 Hz, 2H), 3.17 (tt, J = 8.4, 4.9 Hz, 1H), 2.83 – 2.35 (m, 3H), 2.32 (qd, J = 8.0, 1.8 Hz, 3H), 2.24 (m, 6H), 1.83 (qd, J = 7.6, 5.3 Hz, 2H), 1.58 (q, J = 6.9 Hz, 4H), 1.50 (d, J = 5.9 Hz, 2H), 1.29 (dd, J = 13.2, 5.6 Hz 3-Hexylnonyl 3-(N-decyl-4-(dimethylamino)butanamido)dodecanoate (7). 1 H NMR (400 MHz, CDCl 3 ) δ 4.36 – 4.19 (m, 1H), 4.08 (q, J = 7.2 Hz, 2H), 3.17 (tt, J = 8.1, 4.7 Hz, 2H), 2.77 – 2.36 (m, 4H), 2.32 (qd, J = 7.7, 2.2 Hz, 3H), 2.24 (m, 6H), 1.83 (qd, J = 7.6, 5.1 Hz, 2H), 1.76 (s, 1H), 1.55 (dh, J = 24.3, 6.8 Hz, 5H), 1.37 – 1.18 (m, 47H), 0.90 (t, J = 6.8 Hz, 12H). 3-Pentyloctyl 3-(N-decyl-5-(dimethylamino)pentanamido)dodecanoate (8). 1 H NMR (400 MHz, CDCl 3 ) δ 4.35 – 4.15 (m, 1H), 4.08 (q, J = 7.5 Hz, 2H), 3.23 – 3.09 (m, 1H), 3.06 – 2.91 (m, 1H), 2.80 – 2.33 (m, 3H), 2.29 (ddd, J = 7.7, 6.1, 3.9 Hz, 3H), 2.23 (d, J = 1.2 Hz, 6H), 1.66 (p, J = 7.5 Hz, 3H), 1.61 – 1.45 (m, 7H), 1.37 – 1.14 (m, 44H), 0.90 (td, J = 6.9, 2.7 Hz, 12H). 3-Hexylnonyl 3-(N-decyl-5-(dimethylamino)pentanamido)dodecanoate (9). 1 H NMR (400 MHz, CDCl 3 ) δ 4.26 (s, 1H), 4.08 (q, J = 7.5 Hz, 2H), 3.21 – 3.08 (m, 1H), 2.78 – 2.33 (m, 3H), 2.29 (ddd, J = 7.5, 6.1, 3.7 Hz, 3H), 2.23 (d, J = 1.2 Hz, 6H), 1.67 (p, J = 7.5 Hz, 3H), 1.61 – 1.45 (m, 7H), 1.28 (t, J = 5.7 Hz, 49H), 0.90 (td, J = 6.9, 2.5 Hz, 12H). 3-Pentyloctyl 8-(N-decyl-4-(dimethylamino)butanamido)octadecenoate (10) 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 2.8 Hz, 2H), 3.05 (t, J = 8.3 Hz, 2H), 2.40 (dd, J = 20.2, 11.9 Hz, 6H), 2.29 (td, J = 7.6, 4.9 Hz, 3H), 1.65 – 1.54 (m, 6H), 1.44 (q, J = 6.2 Hz, 5H), 1.29 (d, J = 10.3 Hz, 52H), 0.90 (td, J = 6.9, 2.7 Hz, 12H), 0.09 (s, 2H). 3-Pentyloctyl 8-(N-decyl-5-(dimethylamino)pentanamido)octadecenoate (11). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 2.8 Hz, 2H), 3.04 (t, J = 8.3 Hz, 2H), 2.37 (s, 3H), 2.36 – 2.26 (m, 6H), 1.64 – 1.55 (m, 6H), 1.53 (s, 2H), 1.45 (s, 5H), 1.29 (d, J = 10.2 Hz, 48H), 0.90 (td, J = 6.9, 2.9 Hz, 12H). 3-Hexylnonyl 8-(N-decyl-4-(dimethylamino)butanamido)octadecenoate (12). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 3.0 Hz, 2H), 3.06 (q, J = 6.7 Hz, 2H), 2.47 (s, 1H), 2.42 – 2.34 (m, 6H), 2.29 (td, J = 7.6, 5.1 Hz, 4H), 1.96 – 1.88 (m, 2H), 1.66 – 1.51 (m, 7H), 1.44 (d, J = 7.0 Hz, 5H), 1.29 (d, J = 9.5 Hz, 56H), 0.90 (td, J = 6.9, 2.4 Hz, 12H). 3-Hexylnonyl 8-(N-decyl-5-(dimethylamino)pentanamido)octadecenoate (13). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 2.7 Hz, 2H), 3.08 – 2.99 (m, 2H), 2.47 (s, 2H), 2.34 (d, J = 7.1 Hz, 6H), 2.29 (td, J = 7.5, 5.6 Hz, 3H), 1.75 – 1.54 (m, 10H), 1.45 (s, 5H), 1.29 (d, J = 9.9 Hz, 56H), 0.90 (td, J = 6.8, 2.3 Hz, 12H). 3-Heptyldecyl 8-(N-decyl-4-(dimethylamino)butanamido)octadecenoate (14). NMR (400 MHz, CDCl 3 ) δ 4.09 (td, J = 7.1, 2.9 Hz, 2H), 3.06 (q, J = 6.8 Hz, 2H), 2.62 (s, 2H), 2.40 (dt, J = 9.5, 7.0 Hz, 6H), 2.29 (td, J = 7.5, 5.0 Hz, 2H), 1.98 (s, 2H), 1.59 (tq, J = 16.8, 8.3 Hz, 6H), 1.44 (d, J = 7.2 Hz, 5H), 1.29 (d, J = 9.8 Hz, 61H), 0.90 (td, J = 6.8, 2.1 Hz, 12H). 3-Heptyldecyl 8-(N-decyl-5-(dimethylamino)pentanamido)octadecenoate (15). 1 H NMR (400 MHz, CDCl 3 ) δ 4.09 (td, J = 7.1, 2.6 Hz, 2H), 3.04 (q, J = 7.4 Hz, 2H), 2.67 (s, 2H), 2.53 (s, 6H), 2.41 – 2.24 (m, 4H), 1.72 (s, 4H), 1.60 (dq, J = 13.8, 7.0 Hz, 7H), 1.49 – 1.38 (m, 5H), 1.29 (d, J = 9.3 Hz, 59H), 0.90 (td, J = 6.9, 2.2 Hz, 12H). 3-Pentyloctyl 8-(N-decyl-5-(pyrrolidin-1-yl)pentanamido)octadecanoate (89). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 3.1 Hz, 2H), 3.04 (dd, J = 11.3, 7.0 Hz, 2H), 2.54 – 2.42 (m, 6H), 2.30 (ddd, J = 15.2, 7.7, 5.3 Hz, 4H), 1.83 – 1.75 (m, 4H), 1.70 (dq, J = 16.0, 7.7 Hz, 3H), 1.64 – 1.50 (m, 11H), 1.49 – 1.41 (m, 5H), 1.29 (d, J = 11.0 Hz, 53H), 0.90 (td, J = 6.9, 2.8 Hz, 12H). 3-Hexylnonyl 8-(N-decyl-5-(pyrrolidin-1-yl)pentanamido)octadecanoate (90). NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 3.1 Hz, 2H), 3.04 (dd, J = 10.9, 6.4 Hz, 2H), 2.48 (ddt, J = 18.2, 7.6, 3.0 Hz, 6H), 2.30 (ddd, J = 15.2, 7.7, 5.3 Hz, 4H), 1.79 (q, J = 3.2 Hz, 4H), 1.71 (dd, J = 10.0, 7.2 Hz, 3H), 1.66 – 1.52 (m, 9H), 1.49 – 1.41 (m, 5H), 1.29 (d, J = 10.0 Hz, 55H), 0.90 (td, J = 6.9, 2.4 Hz, 12H). 3-Heptyldecyl 8-(N-decyl-5-(pyrrolidin-1-yl)pentanamido)octadecanoate (91). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.1, 3.1 Hz, 2H), 3.03 (d, J = 12.6 Hz, 2H), 2.54 – 2.42 (m, 6H), 2.30 (ddd, J = 15.3, 7.7, 5.4 Hz, 4H), 1.79 (q, J = 3.6 Hz, 4H), 1.74 – 1.65 (m, 2H), 1.63 – 1.54 (m, 12H), 1.46 (s, 6H), 1.29 (d, J = 10.0 Hz, 54H), 0.90 (td, J = 6.8, 2.3 Hz, 12H). 2-Hexyldecyl 8-(N-decyl-3-(dimethylamino)propanamido)octadecanoate (107). 1 H NMR (400 MHz, CDCl 3 ) δ 3.98 (dd, J = 5.8, 2.7 Hz, 2H), 3.68 – 3.57 (m, 1H), 3.10 – 3.01 (m, 2H), 2.68 (q, J = 8.1 Hz, 2H), 2.51 (q, J = 7.8 Hz, 2H), 2.35 – 2.26 (m, 8H), 1.79 – 1.40 (m, 12H), 1.28 (d, J = 6.6 Hz, 64H), 0.90 (q, J = 4.2 Hz, 12H). 2-Hexyldecyl 9-(N-decyl-3-(dimethylamino)propanamido)nonadecanoate (119). 1 H NMR (400 MHz, CDCl 3 ) δ 3.99 (d, J = 5.7 Hz, 2H), 3.69 – 3.58 (m, 1H), 3.06 (dd, J = 10.8, 5.9 Hz, 2H), 2.70 (dd, J = 10.9, 6.4 Hz, 2H), 2.53 (q, J = 8.1 Hz, 2H), 2.30 (t, J = 4.2 Hz, 8H), 1.71 – 1.11 (m, 77H), 0.90 (t, J = 6.6 Hz, 12H). Example 2. Synthesis of 3-hexylnonyl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2- difluorooctadecanoate (16) Step 1. Synthesis of hexadec-1-en-7-ol A Grignard reagent was prepared with 6-bromohex-1-ene (70 g, 429 mmol) and magnesium (11.2 g, 459 mmol) in THF (150 mL) and stirred at 45˚C for 2 hr. The reaction was cooled to 15˚C and decanal (54 g, 343 mmol) in THF (150 mL) added dropwise. After 1 hr the reaction was cooled (0˚C, ice bath) and quenched with H 2 O followed by 6 M HCl (350 mL). The reaction was extracted with hexane, the organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated column chromatography (2-20% EtOAc-hexane) to give hexadec-1-en-7-ol (65 g, Yield 78.7%). Step 2. Synthesis of hexadec-1-en-7-one Hexadec-1-en-7-ol (65 g, 270 mmol) and PCC-SiO2 (1:1) (140 g, 324 mmol) were stirred in DCM (600 mL) at RT for 18 hr. The mixture was partially concentrated in-vacuo and eluted through a short bed of silica with EtOAc-hexane (25%, 700 mL). The combined organics were concentrated in-vacuo and purified by automated flash chromatography (0-10% EtOAc- hexane) to give hexadec-1-en-7-one (59 g, 91.5%). Step 3. Synthesis of decyl(hexadec-1-en-7-yl)amine Hexadec-1-en-7-one (59 g, 247 mmol), N-decylamine (40.9 g, 260 mmol), NaCNBH3 (47 g, 742 mmol) and AcOH (30 g, 495 mmol) were stirred in MeOH at 50˚C for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in Et 2 O and washed sequentially with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% MeOH-DCM) to give decyl(hexadec-1-en-7-yl)amine (50 g, 53.2%). Step 4. Synthesis of N-decyl-4-(dimethylamino)-N-(hexadec-1-en-7-yl)butanamide 4-Dimethylamino]butanoic acid (HCl salt) (25.4 g, 151 mmol), HATU (60 g, 158 mmol) and DIPEA (46 mL, 263 mmol) were stirred in DCM (500 mL) for 1 hr at RT. Decyl(hexadec-1- en-7-yl)amine (25 g, 66 mmol in DCM (65 mL) was added and the reaction stirred at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in Et 2 O and washed sequentially with 1 M NaOH, NaHCO 3 (sat. soln), water and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% MeOH-DCM) to give N-decyl-4-(dimethylamino)-N-(hexadec-1-en-7-yl)butanamide (20 g, 61.6%). Step 5. Synthesis of ethyl 9-[N-decyl-4-(dimethylamino)butanamido]-2,2- difluorooctadecanoate In a vacuum, heat dried flask, Hantsch ester (2.3 g, 9.13 mmol), NaOAc (2.25 g, 27.4 mmol), AgOTf (5.9 g, 22.8 mmol) and iodobenzene diacetate (5.9 g, 18.3 mmo) were added and the flask evacuated and back filled with nitrogen. NMP (15 mL), N-decyl-4-(dimethylamino)-N- (hexadec-1-en-7-yl)butanamide (4.5 g, 9.1 mmol) in NMP and ethyl 2,2-difluoro-2- (trimethylsilyl)acetate (9.0 g, 46 mmol) were added and the reaction stirred at RT for 18 hr. The mixture was filtered through Celite, eluting with Et 2 O. The organics were washed with water and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% MeOH-DCM) to give ethyl 9-[N-decyl-4- (dimethylamino)butanamido]-2,2-difluorooctadecanoate (5 g, 80.0 %). Step 6. Synthesis of 9-[N-decyl-4-(dimethylamino)butanamido]-2,2-difluorooctadeca noic Ethyl 9-[N-decyl-4-(dimethylamino)butanamido]-2,2-difluorooctadeca noate (5 g, 8.1 mmol) and LiOH (0.39 g, 16.2 mmol) were stirred in THF (50 mL) and H 2 O (10 mL) at 50˚C for 2 hr. The reaction was quenched with 6M HCl (3.0 mL) and partially concentrated. The aqueous residue was diluted with H 2 O and extracted with DCM. The combined organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was azeotroped with toluene (50 mL) to give 9-[N-decyl-4-(dimethylamino)butanamido]-2,2- difluorooctadecanoic acid which was used without purification. Step 7. Synthesis of 3-hexylnonyl 9-[N-decyl-4-(dimethylamino)butanamido]-2,2- difluorooctadecanoate 9-[N-Decyl-4-(dimethylamino)butanamido]-2,2-difluorooctadeca noic acid (4 g, 6.8 mmol), 3-hexylnonan-1-ol (1.63 g, 7.1 mmol), 2,4,6 trichlorobenzoyl chloride (1.8 g, 7.5 mmol) and DMAP (1.7 g, 13.6 mmol were stirred in DCM (100 mL) at RT for 3 hr. The reaction was concentrated in-vacuo and the residue partitioned between Et 2 O and H 2 O. The organics were washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-12% MeOH-DCM) to give 3- hexylnonyl 9-[N-decyl-4-(dimethylamino)butanamido]-2,2-difluorooctadeca noate (16) (2.44 g, 44.9 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (td, J = 7.1, 1.9 Hz, 2H), 3.66 (dd, J = 9.4, 4.8 Hz, 1H), 3.06 (q, J = 7.1 Hz, 2H), 2.41 – 2.31 (m, 4H), 2.27 (s, 6H), 2.13 – 1.96 (m, 2H), 1.87 (h, J = 7.3 Hz, 2H), 1.67 (q, J = 6.9 Hz, 2H), 1.60 – 1.39 (m, 9H), 1.28 (q, J = 6.6 Hz, 56H), 0.95 – 0.84 (m, 12H). 19 F NMR (376 MHz, CDCl 3 ) δ -105.9 (2F). The following compounds were prepared using analogous methodology as described above 2-Hexyldecyl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (17). 1 H NMR (400 MHz, CDCl 3 ) δ 4.18 (dd, J = 6.0, 2.0 Hz, 2H), 3.69 – 3.57 (m, 1H), 3.06 (q, J = 7.1 Hz, 2H), 2.57 (s, 2H), 2.46 – 2.34 (m, 8H), 2.01 – 1.89 (m, 3H), 1.59 – 1.40 (m, 8H), 1.38 – 1.18 (m, 60H), 0.90 (td, J = 6.8, 2.7 Hz, 12H). 3-Heptyldecyl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (18). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (td, J = 7.1, 1.9 Hz, 2H), 3.71 – 3.56 (m, 1H), 3.06 (q, J = 7.0 Hz, 2H), 2.42 – 2.29 (m, 8H), 2.04 (ddt, J = 16.8, 11.4, 5.3 Hz, 3H), 1.91 (h, J = 7.1 Hz, 3H), 1.67 (q, J = 6.9 Hz, 2H), 1.60 – 1.39 (m, 9H), 1.29 (d, J = 8.3 Hz, 53H), 0.90 (td, J = 6.7, 3.1 Hz, 12H). Undecan-6-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (19). 1 H NMR (400 MHz, CDCl 3 ) δ 3.57 (s, 1H), 3.28 (q, J = 7.8 Hz, 2H), 3.06 (dd, J = 11.9, 5.3 Hz, 2H), 2.94 (d, J = 2.3 Hz, 6H), 2.60 (t, J = 5.9 Hz, 1H), 2.53 (t, J = 5.9 Hz, 1H), 2.18 – 1.75 (m, 11H), 1.70 – 1.42 (m, 13H), 1.42 – 1.16 (m, 55H), 0.90 (t, J = 6.6 Hz, 12H). 3-Pentyloctyl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (20). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (td, J = 7.1, 1.9 Hz, 2H), 3.71 – 3.60 (m, 1H), 3.06 (q, J = 7.4 Hz, 2H), 2.35 (tdd, J = 6.6, 4.2, 2.4 Hz, 4H), 2.26 (s, 6H), 2.13 – 1.96 (m, 3H), 1.85 (h, J = 7.4 Hz, 2H), 1.68 (q, J = 6.8 Hz, 2H), 1.60 – 1.40 (m, 9H), 1.38 – 1.19 (m, 49H), 0.94 – 0.86 (m, 12H). Tridecan-7-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (92). 1 H NMR (400 MHz, CDCl 3 ) δ 5.02 (p, J = 6.8 Hz, 1H), 3.65 (t, J = 7.2 Hz, 1H), 3.06 (q, J = 7.1 Hz, 2H), 2.40 – 2.31 (m, 4H), 2.29 (s, 6H), 2.16 – 1.94 (m, 2H), 1.68 – 1.10 (m, 65H), 0.90 (t, J = 6.7 Hz, 12H). Pentadecan-8-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (93). 1 H NMR (400 MHz, CDCl 3 ) δ 5.09 – 4.94 (m, 1H), 3.65 (t, J = 7.2 Hz, 1H), 3.06 (q, J = 7.0 Hz, 2H), 2.37 (dt, J = 14.7, 7.7 Hz, 4H), 2.30 (s, 6H), 2.20 – 1.97 (m, 2H), 1.88 (h, J = 7.2 Hz, 2H), 1.67 – 1.08 (m, 68H), 0.90 (t, J = 6.7 Hz, 12H). Pentadecan-8-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (101). 1 H NMR (400 MHz, CDCl 3 ) δ 5.01 (q, J = 5.8 Hz, 1H), 3.78 – 3.57 (m, 1H), 3.15 – 2.94 (m, 2H), 2.58 – 2.17 (m, 10H), 2.04 (tq, J = 16.1, 7.6 Hz, 2H), 1.88 (h, J = 7.5 Hz, 2H), 1.73 – 1.01 (m, 66H), 0.90 (t, J = 6.6 Hz, 12H). 2-Hexyldecyl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (102). 1 H NMR (400 MHz, CDCl 3 ) δ 4.18 (dd, J = 5.7, 3.2 Hz, 2H), 3.71 – 3.61 (m, 0H), 3.05 (dd, J = 10.6, 6.2 Hz, 2H), 2.59 – 2.27 (m, 9H), 2.06 (dp, J = 16.6, 8.1 Hz, 1H), 1.92 (q, J = 7.2 Hz, 2H), 1.73 (s, 1H), 1.59 – 1.40 (m, 8H), 1.29 (dt, J = 10.2, 6.3 Hz, 53H), 0.90 (td, J = 6.7, 2.7 Hz, 12H). 3-Hexylnonyl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (103). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (td, J = 7.1, 2.9 Hz, 2H), 3.65 (d, J = 8.4 Hz, 1H), 3.05 (dd, J = 10.5, 6.2 Hz, 2H), 2.49 (s, 2H), 2.45 – 2.31 (m, 7H), 2.04 (tt, J = 16.5, 8.2 Hz, 2H), 1.91 (p, J = 7.0 Hz, 2H), 1.72 – 1.62 (m, 2H), 1.59 – 1.40 (m, 13H), 1.29 (d, J = 8.3 Hz, 53H), 0.90 (td, J = 6.8, 3.0 Hz, 12H). Heptadecan-9-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorooctadeca noate (104). 1 H NMR (400 MHz, CDCl 3 ) δ 5.06 – 4.96 (m, 1H), 3.74 – 3.50 (m, 1H), 3.06 (q, J = 7.1 Hz, 2H), 2.64 – 2.26 (m, 9H), 2.14 – 1.89 (m, 4H), 1.73 – 1.12 (m, 71H), 0.90 (t, J = 6.8 Hz, 12H). Undecan-6-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (108). 1 H NMR (400 MHz, CDCl 3 ) δ 5.01 (d, J = 8.0 Hz, 1H), 3.67 (s, 0H), 3.05 (d, J = 10.4 Hz, 2H), 2.35 (q, J = 7.7 Hz, 4H), 2.27 (s, 6H), 2.05 (dt, J = 16.2, 8.2 Hz, 2H), 1.86 (h, J = 7.7 Hz, 2H), 1.67 – 1.42 (m, 8H), 1.40 – 1.24 (m, 41H), 0.94 – 0.86 (m, 12H). Tridecan-7-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (107). 1 H NMR (400 MHz, CDCl 3 ) δ 5.14 – 4.93 (m, 1H), 3.05 (dd, J = 11.0, 6.0 Hz, 2H), 2.35 (q, J = 7.4 Hz, 3H), 2.27 (s, 5H), 2.03 (tt, J = 16.2, 8.2 Hz, 2H), 1.87 (h, J = 7.5 Hz, 2H), 1.74 – 1.41 (m, 10H), 1.34 – 1.21 (m, 47H), 0.90 (t, J = 6.6 Hz, 12H). Heptadecan-9-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2,2-difluorohexadeca noate (110). 1 H NMR (400 MHz, CDCl 3 ) δ 5.01 (d, J = 7.4 Hz, 1H), 3.05 (dd, J = 10.9, 6.1 Hz, 2H), 2.52 (s, 2H), 2.39 (d, J = 6.2 Hz, 7H), 2.15 – 1.87 (m, 3H), 1.73 – 1.40 (m, 10H), 1.29 (d, J = 8.5 Hz, 54H), 0.90 (t, J = 6.7 Hz, 12H). Example 3. Synthesis of 2-hexyldecyl 3-{6-[(2-butyloctyl)oxy]-N-[3- (dimethylamino)propyl]-6-oxohexanamido}dodecanoate (21) Step 1. Synthesis of methyl 3-oxododecanoate Meldrum's acid (15 g, 104 mmol) and pyridine (16.5 g, 208 mmol) were stirred in DCM (250 mL) at 0˚C. Decanoyl chloride (21.6 mL, 104 mmol) was added dropwise and the reaction stirred for 16 hr allowing to warm to RT. The reaction was washed with 1M HCl, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was refluxed in MeOH (200 mL) for 3.5 hr then concentrated in-vacuo. The residue was purified by automated flash chromatography (2-20% EtOAc-hexane) to give methyl 3-oxododecanoate (17.7 g, 74.4%). Step 2. Synthesis of 3-{[3-(dimethylamino)propyl]amino}dodecanoate Methyl 3-oxododecanoate (7.92 g, 34.7 mmol), DMAP (4.08 g, 40.0 mmol) and AcOH (7.9 mL, 139 mmol) were heated at reflux in MeOH (285 mL) for 1 hr, then cooled to 0˚C and treated portion wise with NaCNBH3 (4.9 g, 69 mmol). The reaction was stirred at RT for 40 hr, partially concentrated in-vacuo, the residue taken up in EtOAc and washed sequentially with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH-DCM) to give 3-{[3- (dimethylamino)propyl]amino}dodecanoate (1.9 g, 17.4%). Step 3. Synthesis of methyl 3-{[(benzyloxy)carbonyl][3-(dimethylamino)- propyl]amino}dodecanoate Methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (1.2 g, 3.8 mmol), CBz-OSu (1.0 g, 4.2 mmol) and TEA (0.8 mL, 5.7 mmol) were stirred in DCM (35 mL) at RT for 18 hr. The organics were washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (50:50 EtOAc/Hex) to give methyl 3-{[(benzyloxy)carbonyl][3- (dimethylamino)propyl]amino}dodecanoate (1.6 g, 93.5%). Step 4. Synthesis of 3-(((benzyloxy)carbonyl)(3-(dimethylamino)propyl)amino)dodec anoic Methyl 3-{[(benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec anoate (1.68 g, 3.7 mmol) and LiOH (0.18 g, 7.5 mmol) were heated at 50˚C in MeOH/H 2 O (20:3) for 18 hr. The reaction was cooled to RT, quenched with 1M HCl (1.3 mL) and concentrated in- vacuo. The residue was taken-up in DCM, washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-(((benzyloxy)carbonyl)(3- (dimethylamino)propyl)amino)dodecanoic acid which was used without purification. Step 5. Synthesis of 2-hexyldecyl 3-{[(benzyloxy)carbonyl][3-(dimethylamino)- propyl]amino}dodecanoate 3-{[(Benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec anoic acid (1.2 g, 2.8 mmol), hexyldecanol (0.72 g, 3.0 mmol), EDC (1.04 g, 5.4 mmol), DIPEA (1.4 mL, 8.1 mmol) and DMAP (cat.) were stirred in DCM (30 mL) at RT for 18hr. The reaction was washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography to give 2-hexyldecyl 3-{[(benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec anoate (827 mg, 46.2%). Step 6. Synthesis of 2-hexyldecyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate 2-Hexyldecyl 3-{[(benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec anoate (874 mg, 1.3 mmol) was subjected to catalytic hydrogenation over 10% Pd/C in MeOH (5 mL) for 18 hr. The reaction was filtered through Celite, concentrated in-vacuo and the crude purified by automated flash chromatography (0-15%MeOH/DCM) to give 2-hexyldecyl 3-{[3- (dimethylamino)propyl]amino}dodecanoate (294 mg, 42.2%). Step 7. Synthesis of 2-hexyldecyl 3-{6-[(2-butyloctyl)oxy]-N-[3-(dimethylamino)propyl]-6- oxohexanamido}dodecanoate (21) 6-[(2-Butyloctyl)oxy]-6-oxohexanoic acid (252 mg, 0.8 mmol) and oxalyl chloride (0.20 g, 1.7 mmol) were stirred at RT for 3 hr. The reaction was concentrated in-vacuo and the residue re-dissolved in DCM (5 mL). The acid chloride intermediate was added to 2-hexyldecyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (295 mg, 0.6 mmol) and TEA (0.14 ml, 1.6 mmol) in DCM (5 mL) and stirred at RT for 2 hr. The reaction was diluted with DCM, washed with NaHCO 3 (sat. soln) and brine, dried (MgSO4), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10 %MeOH/DCM) to give 2-hexyldecyl 3-{6-[(2-butyloctyl)oxy]-N-[3-(dimethylamino)propyl]-6- oxohexanamido}dodecanoate (21) (231 mg, 50.%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.23 (s, 1H), 3.95 (q, J = 5.3 Hz, 4H), 3.22 (q, J = 8.2 Hz, 2H), 3.04 (s, 1H), 2.52 (td, J = 15.1, 6.8 Hz, 2H), 2.40 – 2.23 (m, 6H), 2.21 (s, 6H), 1.79 – 1.55 (m, 11H), 1.25 (q, J = 4.8 Hz, 53H), 0.88 (td, J = 6.7, 3.9 Hz, 15H). The following compound was prepared using analogous methodology as described above. 2-Hexyldecyl 3-(8-((2-butyloctyl)oxy)-N-(3-(dimethylamino)propyl)-8-oxooc tanamido)- dodecanoate (22). 1 H NMR (400 MHz, CDCl 3 ) δ 4.27 (s, 1H), 3.97 (t, J = 6.4 Hz, 4H), 3.24 (dq, J = 12.2, 6.8 Hz, 2H), 3.07 (d, J = 4.7 Hz, 1H), 2.62 – 2.45 (m, 2H), 2.36 – 2.25 (m, 5H), 2.24 (s, 6H), 1.71 – 1.59 (m, 8H), 1.29 (q, J = 4.6 Hz, 57H), 0.91 (td, J = 6.7, 3.9 Hz, 15H). Example 4. Synthesis of Synthesis of tridecyl 6-{6-[(2-butyloctyl)oxy]-N-[2- (dimethylamino)ethyl]-6-oxohexanamido}hexadecanoate (23) Step 1. Synthesis of tridecyl 6-{[2-(dimethylamino)ethyl]amino}hexadecanoate Tridecyl 6-oxohexadecanoate (377 mg, 0.83 mmol) 1,1-dimethylethylenediamine (81 mg, 0.92 mmol) AcOH (0.1 mL, 1.7 mmol) and NaCNBH3 (157 mg, 2.5 mmol) were stirred in MeOH at 50˚C for 2 hr. The reaction was removed from heat and stirring continued for an additional 30 hr. The reaction was partially concentrated in-vacuo then dissolved in DCM, washed (NaHCO 3 and brine), dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-15% MeOH-DCM) to give tridecyl 6-{[2-(dimethylamino)ethyl]amino}hexadecanoate (201 mg, 46.0 %). Step 2. Synthesis of 6-{6-[(2-butyloctyl)oxy]-N-[2-(dimethylamino)ethyl]-6- oxohexanamido}hexadecanoate (23) 6-[(2-Butyloctyl)oxy]-6-oxohexanoic acid (0.2 g, 0.64 mmol) and oxalyl chloride (0.15 mL, 1.74 mmol) were stirred in DCM (10 mL) with DMF (1 drop) at RT for 3 hr. The reaction was concentrated in-vacuo, the residue taken-up in DCM (5 mL) and added to tridecyl 6-{[2-(dimethylamino)ethyl]amino}hexadecanoate (303 mg, 0.6 mmol) and TEA (0.32 mL, 2.3 mmol) in DCM (10 mL). After stirring at RT for 1 hr the reaction was diluted with DCM, washed (NaHCO 3 (sat. aq.) and brine), dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH-DCM) to give tridecyl 6-{6-[(2-butyloctyl)oxy]-N-[2-(dimethylamino)ethyl]-6-oxohex anamido}hexadecanoate (23) (113 mg, 23.8 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.07 (td, J = 6.8, 4.4 Hz, 2H), 3.99 (d, J = 5.8 Hz, 2H), 3.31 (d, J = 8.4 Hz, 1H), 2.58 (s, 1H), 2.47 – 2.25 (m, 12H), 1.74 – 1.58 (m, 9H), 1.49 (td, J = 11.9, 7.6 Hz, 4H), 1.39 – 1.16 (m, 52H), 0.91 (m, 12H). The following compounds were prepared using analogous methodology as described above. Tridecyl 6-(8-((2-butyloctyl)oxy)-N-(2-(dimethylamino)ethyl)-8-oxooct anamido)- hexadecanoate (24). 1 H NMR (400 MHz, CDCl 3 ) δ 4.07 (td, J = 6.8, 4.4 Hz, 2H), 3.99 (d, J = 5.8 Hz, 2H), 3.31 (d, J = 8.4 Hz, 1H), 2.58 (s, 1H), 2.47 – 2.25 (m, 12H), 1.74 – 1.58 (m, 9H), 1.49 (td, J = 11.9, 7.6 Hz, 4H), 1.39 – 1.16 (m, 52H), 0.91 (m, 12H). 2-Hexyldecyl 5-(8-((2-butyloctyl)oxy)-N-(3-(dimethylamino)propyl)-8-oxooc tanamido)- pentadecanoate (25). 1 H NMR (400 MHz, CDCl 3 ) δ 3.99 (dd, J = 5.8, 2.1 Hz, 4H), 3.14 (dd, J = 11.0, 5.8 Hz, 2H), 2.44 – 2.22 (m, 13H), 1.71 – 1.60 (m, 7H), 1.48 (s, 6H), 1.40 – 1.16 (m, 60H), 0.91 (td, J = 6.7, 4.0 Hz, 15H). 7-Hexyltridecyl 7-(N-(3-(dimethylamino)propyl)-8-oxo-8-(undecan-3-yloxy)octa namido)- heptadecanoate (26). 1 H NMR (400 MHz, CDCl 3 ) δ 4.12 – 4.02 (m, 3H), 2.46 – 2.15 (m, 14H), 1.59 (dt, J = 34.1, 5.6 Hz, 28H), 1.42 – 1.16 (m, 58H), 0.98 – 0.79 (m, 15H). 5-Octyltridecyl 7-(N-(3-(dimethylamino)propyl)-8-oxo-8-(undecan-3-yloxy)octa namido)- heptadecanoate (27). 1 H NMR (400 MHz, CDCl 3 ) δ 3.69 – 3.63 (m, 1H), 3.36 – 3.29 (m, 2H), 2.36 – 2.27 (m, 2H), 2.15 – 1.96 (m, 14H), 1.85 – 1.48 (m, 44H), 1.46 – 1.16 (m, 44H), 0.89 (t, J = 6.7 Hz, 15H). 5-Octyltridecyl 7-(N-(2-(dimethylamino)ethyl)-8-oxo-8-(undecan-3-yloxy)octan amido)- heptadecanoate (28). 1 H NMR (400 MHz, CDCl 3 ) δ 3.69 – 3.63 (m, 1H), 3.35 – 3.28 (m, 2H), 2.18 – 1.93 (m, 15H), 1.89 – 1.82 (m, 2H), 1.71 – 1.55 (m, 41H), 1.43 – 1.19 (m, 44H), 0.89 (t, J = 6.7 Hz, 15H). 2-Hexyldecyl 7-(8-((2-butyloctyl)oxy)-N-(3-(dimethylamino)propyl)-8-oxooc tanamido)- heptadecanoate (29). 1 H NMR (400 MHz, CDCl 3 ) δ 4.03 – 3.94 (m, 4H), 3.67 – 3.61 (m, 1H), 3.18 – 3.09 (m, 2H), 2.42 – 2.12 (m, 12H), 1.81 – 1.41 (m, 24H), 1.41 – 1.03 (m, 56H), 0.90 (t, J = 3.2 Hz, 15H). 3-Pentyloctyl 8-(N-(3-(dimethylamino)propyl)-8-oxo-8-((3-pentyloctyl)oxy)- octanamido)octadecenoate (30). 1 H NMR (400 MHz, CDCl 3 ) δ 4.14 – 4.07 (m, 4H), 3.67 – 3.61 (m, 1H), 3.19 – 3.11 (m, 2H), 2.36 – 2.21 (m, 10H), 1.72 – 1.53 (m, 22H), 1.53 – 1.39 (m, 6H), 1.39 – 1.18 (m, 52H), 0.97 – 0.84 (m, 15H). Heptadecan-9-yl 8-(N-(3-(dimethylamino)propyl)-8-oxo-8-((3-pentyloctyl)oxy)- octanamido)octadecenoate (31). 1 H NMR (400 MHz, CDCl 3 ) δ 4.91 – 4.85 (m, 1H), 4.10 (t, J = 7.1 Hz, 2H), 2.42 – 2.19 (m, 12H), 2.04 – 1.83 (m, 12H), 1.77 – 1.46 (m, 18H), 1.39 – 1.13 (m, 60H), 0.96 – 0.82 (m, 15H). Example 5. Synthesis of Synthesis of 2-hexyldecyl 3-[N-decyl-4-(dimethylamino)- butanamido]dodecanoate (32) Step 1. Synthesis of methyl 3-(decylamino)dodecanoate Methyl 3-oxododecanoate (1 g, 4.4 mmol), N-decylamine (723 mg, 5.0 mmol), NaCNBH3 (826 mg, 13.1 mmol) and AcOH (0.5 mL, 8.8 mmol) were stirred in MeOH in methanol at 50˚C for 18 hr. The reaction was cooled to RT and partially concentrated in- vacuo. The mixture was taken-up in DCM, washed with NaHCO 3 (sat. aq.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH-DCM) to give methyl 3-(decylamino)dodecanoate (560 mg, 34.6%). Step 2. Synthesis of methyl 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoate 4-Dimethylamino]butanoic acid HCl salt (508 mg, 3.03 mmol), DCC (688 mg, 3.3 mmol) and DMAP (555 mg, 4.5 mmol) were stirred in MeCN (5 mL) at RT for 2 hr. Methyl 3-(decylamino)dodecanoate (560 mg, 1.5 mmol) in DCM (5 mL) was added and stirring continued for 72 hr. The reaction was filtered through Celite, rinsed with DCM and the filtrate washed with NaHCO 3 (sat. aq.) and brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography (0-10% MeOH- DCM) to give methyl 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoate (498 mg, 68.1 %). Step 3. Synthesis of 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoic acid Methyl 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoate (498 mg, 1.0 mmol) and LiOH (49 mg, 2.1 mmol) were stirred in MeOH (3.0 mL) and H 2 O water (0.5 mL) at 50˚C for 2 hr. The reaction was cooled to RT and quenched with 6 M HCl (0.35 mL). The reaction was partially concentrated in-vacuo then partitioned between H 2 O water and DCM. The aqueous layer was extracted with DCM and the combined organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoic acid (409 mg, 84.6 %) which was used without further purification. Step 4. Synthesis of 2-hexyldecyl 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoate (32) 3-[N-Decyl-4-(dimethylamino)butanamido]dodecanoic acid (369 mg, 0.8 mmol), hexyldecanol (229 mg, 0.95 mmol), EDC (302 mg, 1.6 mmol), DIPEA (0.411 mL, 2.4 mmol) and DMAP (cat.) were stirred in DCM (5 mL) at RT for 18 hr. The reaction was washed with NaHCO 3 (sat. aq.) and brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH- DCM) to give 2-hexyldecyl 3-[N-decyl-4-(dimethylamino)butanamido]dodecanoate (32). (88 mg, 16.1 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.26 (s, 1H), 4.03 – 3.93 (m, 2H), 3.89 – 3.76 (m, 1H), 3.16 (ddt, J = 15.2, 10.6, 5.7 Hz, 1H), 2.98 (s, 1H), 2.79 – 2.22 (m, 13H), 1.90 (ddd, J = 27.0, 14.0, 7.1 Hz, 3H), 1.51 (dq, J = 22.6, 6.4 Hz, 5H), 1.28 (q, J = 4.2 Hz, 51H), 0.90 (m, 12H). Example 6. Synthesis of Synthesis of 2-hexyldecyl 8-(N-{7,7-difluoro-8-[(2- hexyldecyl)oxy]-8-oxooctyl}-4-(dimethylamino)butanamido)octa decenoate (33) Step 1. Synthesis of methyl 8-oxooctadecanoate 8-Oxooctadecanoic acid (3.3 g, 10.9 mmol was stirred in MeOH (60 mL) at 0˚C. Thionyl chloride (1.43 g, 12.0 mmol) was added dropwise and the reaction stirred for 18 hr allowing to warm to RT. The reaction was concentrated in-vacuo, the residue taken-up in hexane and washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO4), filtered and concentrated in- vacuo. The crude material was purified by automated flash chromatography (2-20% EtOAc- hexane) to give methyl 8-oxooctadecanoate (3.33 g, 97.9%). Step 2. Synthesis of methyl 8-(hex-5-en-1-ylamino)octadecenoate Methyl 8-oxooctadecanoate (2.68 g, 8.6 mmol), hex-5-en-1-amine (0.94 g, 9.4 mmol), AcOH (1.0 mL, 17.2 mmol) and NaCNBH3 (1.62 g, 25.7 mmol) were stirred in MeOH (32 mL) at 50 ˚C for 18hr. The reaction was concentrated in-vacuo, the residue taken-up in EtOAc and washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated. The crude material was purified by automated flash chromatography (0-10% MeOH-DCM) to give methyl 8-(hex-5-en-1-ylamino)octadecanoate (2.1 g, 61.9%). Step 3. Synthesis of 8-[4-(dimethylamino)-N-(hex-5-en-1-yl)butanamido]octadecenoa te 4-Dimethylaminobutanoic acid (HCl salt) (1.8 g, 10.6 mmol), HATU (4.0 g, 10.6 mmol) and DIPEA (3.7 mL, 21.2 mmol) were stirred in DCM (50 mL) at RT for 1 hr. Methyl 8-(hex-5-en-1-ylamino)octadecanoate (2.1 g, 5.3 mmol) in DCM (5 mL) was added and the reaction stirred at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in EtOAc and washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (1- 15% MeOH-DCM) to give methyl 8-[4-(dimethylamino)-N-(hex-5-en-1- yl)butanamido]octadecanoate (2.0 g, 74.1%). Step 4. Synthesis of methyl 8-[4-(dimethylamino)-N-[(5E)-8-ethoxy-7,7-difluoro-8-oxooct- 5-en-1-yl]butanamido]octadecenoate In a vacuum, heat dried flask, Hantzch ester (1.0 g, 3.9 mmol), Iodobenzenediacetate (2.5 g, 7.9 mmol), NaOAc (1.0 g, 11.8 mmol) and AgOTf (2.5 g, 9.8 mmol) were purged with nitrogen and dissolved in NMP (40 mL). Methyl 8-[4-(dimethylamino)-N-(hex-5-en-1- yl)butanamido]octadecanoate (2 g, 3.9 mmol) and ethyl 2,2-difluoro-2-(trimethylsilyl)acetate (3.6 g, 20.0 mmol) were added and the reaction stirred at RT for 18 hr. The reaction was filtered through Celite, the filtrate washed with water and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0- 10% MeOH-DCM) to give methyl 8-[4-(dimethylamino)-N-[(5E)-8-ethoxy-7,7-difluoro-8- oxooct-5-en-1-yl]butanamido]octadecanoate (2.21 g, 66.8%). Step 5. Synthesis of 2-hexyldecyl 8-(N-{7,7-difluoro-8-[(2-hexyldecyl)oxy]-8-oxooctyl}-4- (dimethylamino)butanamido)octadecenoate (33). Methyl 8-[4-(dimethylamino)-N-(8-ethoxy-7,7-difluoro-8-oxooctyl)but anamido]- octadecanoate (2.21 g, 3.9 mmol) and LiOH (335 mg, 14.0 mmol) were stirred in THF (22 mL ) and H 2 O (6.6 mL) at 50˚C for 2 hr. The reaction was quenched with 6M HCl (11.6 mL) and partially concentrated in-vacuo. The aqueous was diluted with HCl (1M) and extracted with DCM. The combined organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo azeotroping with toluene. The bis-acid and 2-hexyldecan-1-ol (1.8 g, 7.3 mmol) were dissolved in DCM (22 mL) and 2,4,6 trichlorobenzoyl chloride (1.87 g, 7.76 mmol) and DMAP (1.71 g, 14.0 mmol) added. The reaction was stirred at RT for 18 hr, concentrated in-vacuo and the residue taken-up in EtOAc. The organics were washed with NaHCO 3 (sat. soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by flash chromatography (0- 12% MeOH-DCM) to give 2-hexyldecyl 8-(N-{7,7-difluoro-8-[(2-hexyldecyl)oxy]-8-oxooctyl}- 4-(dimethylamino)butanamido)octadecenoate (33) (615 mg, 16.9%). 1 H NMR (400MHz, CDCl 3 ) δ 4.18 (dd, J = 5.8, 4.0 Hz, 2H), 3.98 (dd, J = 5.8, 3.2 Hz, 2H), 3.65 (t, J = 7.2 Hz, 1H), 3.11 – 3.00 (m, 2H), 2.39 – 2.28 (m, 6H), 2.26 (s, 6H), 2.16 – 1.97 (m, 3H), 1.85 (dt, J = 9.2, 6.9 Hz, 3H), 1.73 (s, 1H), 1.68 – 1.38 (m, 13H), 1.29 (m,73H), 0.95 – 0.86 (m, 15H). 19 F NMR (376MHz, CDCl 3 ) δ -105.78 (m, 2F). The following compounds were prepared using analogous methodology as described above. Tridecan-7-yl 8-(N-(7,7-difluoro-8-oxo-8-(tridecan-7-yloxy)octyl)-4-(dimet hylamino)- butanamido)octadecanoate (116). 1 H NMR (400 MHz, CDCl 3 ) δ 5.02 (q, J = 6.5 Hz, 1H), 4.89 (t, J = 6.4 Hz, 1H), 3.67 (d, J = 7.8 Hz, 0H), 3.40 (s, 0H), 3.06 (t, J = 8.0 Hz, 2H), 2.38 – 2.25 (m, 5H), 2.24 (s, 4H), 2.07 (tq, J = 16.8, 9.2 Hz, 2H), 1.84 (q, J = 8.1 Hz, 2H), 1.73 – 1.15 (m, 59H), 0.90 (t, J = 6.6 Hz, 12H). Pentadecan-8-yl 8-(N-(7,7-difluoro-8-oxo-8-(pentadecan-8-yloxy)octyl)-4- (dimethylamino)butanamido)octadecanoate (117). 1 H NMR (400 MHz, CDCl 3 ) δ 5.07 – 4.98 (m, 1H), 4.88 (td, J = 6.5, 3.1 Hz, 1H), 3.64 (s, 0H), 2.47 (s, 1H), 2.42 – 2.24 (m, 7H), 2.06 (tt, J = 16.7, 8.3 Hz, 2H), 1.96 – 1.88 (m, 2H), 1.72 – 1.15 (m, 65H), 0.90 (t, J = 6.7 Hz, 12H). Heptadecan-9-yl 8-(N-(7,7-difluoro-8-(heptadecan-9-yloxy)-8-oxooctyl)-4- (dimethylamino)butanamido)octadecanoate (118). NMR (400 MHz, CDCl 3 ) δ 5.02 (q, J = 5.9 Hz, 1H), 4.88 (t, J = 6.1 Hz, 1H), 3.64 (s, 1H), 3.43 – 3.38 (m, 0H), 3.06 (dd, J = 11.6, 5.5 Hz, 2H), 2.51 (s, 2H), 2.43 – 2.24 (m, 7H), 2.07 (tq, J = 16.7, 9.2 Hz, 2H), 1.93 (q, J = 7.2 Hz, 2H), 1.72 – 1.13 (m, 76H), 0.90 (t, J = 6.7 Hz, 12H). Example 7. Synthesis of Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{6-fluoro-7- oxo-7-[(3-pentyloctyl)oxy]heptyl}butanamido]-2-fluorooctadec anoate (34) Step 1. Synthesis of [1-(oxan-2-yloxy)hexadecan-7-yl][5-(oxan-2-yloxy)pentyl]amin e 1-(Oxan-2-yloxy)hexadecan-7-one (9.9 g, 29.1 mmol), 5-(oxan-2-yloxy)pentan-1-amine (6 g, 32.0 mmol) and Na(OAc)3BH (18.5 g, 87.4 mmol) were stirred in THF (100 mL) at 50˚C for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in Et 2 O, washed with NaHCO 3 (sat. soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% MeOH-DCM) to give [1- (oxan-2-yloxy)hexadecan-7-yl][5-(oxan-2-yloxy)pentyl]amine (5.2 g, 34.9%). Step 2. Synthesis of 4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl]-N-[5-(o xan-2- yloxy)pentyl]butanamide 4-Dimethylamino]butanoic acid (HCl salt) (5.2 g, 31.1 mmol), HATU (11.8 g, 31.0 mmol) and DIPEA (10.8 mL, 62.1 mmol) were stirred in DCM (75 mL) at RT for 1hr. [1- (Oxan-2-yloxy)hexadecan-7-yl][5-(oxan-2-yloxy)pentyl]amine (5.3 g, 10.4 mmol) solution in DCM (10mL) was added and stirring continued at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in EtOAc, washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (1-15% MeOH-DCM) to give 4-(dimethylamino)-N-[1-(oxan-2- yloxy)hexadecan-7-yl]-N-[5-(oxan-2-yloxy)pentyl]butanamide (2.08 g, 32.1%). Step 3. Synthesis of 4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)-N-(5- 4-(Dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl]-N-[5-(o xan-2- yloxy)pentyl]butanamide (2.08 g, 3.3 mmol) and pTsOH-H 2 O (127 mg, 0.7 mmol) were stirred in MeOH (25 mL) at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken- up in EtOAc, washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)-N-(5- hydroxypentyl)butanamide (1.5 g, 98.7%) which was used without further processing. Step 4. Synthesis of 4-(dimethylamino)-N-(1-oxohexadecan-7-yl)-N-(5-oxopentyl)- butanamide 4-(Dimethylamino)-N-(1-hydroxyhexadecan-7-yl)-N-(5-hydroxype ntyl)butanamide (1.5 g, 3.3 mmol) and PCC-SiO2 (1:1) (5.0 g, 11.5 mmol) were stirred in DCM (30 mL) at RT for 18 hr. The mixture with filtered through a bed of silica, eluting with EtOAc. The filtrate was concentrated in-vacuo and the crude material purified by automated flash chromatography (0- 12% MeOH-DCM) to give 4-(dimethylamino)-N-(1-oxohexadecan-7-yl)-N-(5- oxopentyl)butanamide (486 mg, 32.7%). Step 5. Synthesis of ethyl (2Z)-9-[4-(dimethylamino)-N-[(5Z)-7-ethoxy-6-fluoro-7-oxohep t- 5-en-1-yl]butanamido]-2-fluorooctadec-2-enoate 4-(Dimethylamino)-N-(1-oxohexadecan-7-yl)-N-(5-oxopentyl)but anamide (346 mg, 0.76 mmol), ethyl 2-(diethoxyphosphoryl)-2-fluoroacetate (0.62 mL, 3.1 mmol) and DBU (0.46 mL, 3.1 mmol) were stirred in THF (10 mL) at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in EtOAc, washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% MeOH-DCM) to give ethyl (2Z)-9-[4- (dimethylamino)-N-[(5Z)-7-ethoxy-6-fluoro-7-oxohept-5-en-1-y l]butanamido]-2-fluorooctadec- 2-enoate (116 mg, 24.1%). Step 6. Synthesis of ethyl 9-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7-oxoheptyl)- butanamido]-2-fluorooctadecanoate Ethyl (2Z)-9-[4-(dimethylamino)-N-[(5Z)-7-ethoxy-6-fluoro-7-oxohep t-5-en-1- yl]butanamido]-2-fluorooctadec-2-enoate (116 mg, 0.18 mmol) was subjected to catalytic hydrogenation over Pd/C (10% w/w) (15 mg) in EtOAc (5 mL) at RT for 18 hr. The mixture was filtered through Celite and the filtrate concentrated in-vacuo to give ethyl 9-[4-(dimethylamino)- N-(7-ethoxy-6-fluoro-7-oxoheptyl)butanamido]-2-fluorooctadec anoate (117 mg, 100%) that was used without purification. Step 7. Synthesis of 9-[N-(6-carboxy-6-fluorohexyl)-4-(dimethylamino)butanamido]- 2- fluorooctadecanoic acid Ethyl 9-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7-oxoheptyl)butana mido]-2- fluorooctadecanoate (117 mg, 0.19 mmol) and LiOH (18 mg, 0.74 mmol) were stirred in THF (0.6 mL) and H 2 O water (0.18 mL) at 50˚C for 2 hr. The reaction was cooled to RT, quenched with 6 M HCl (0.126 mL) and extracted with DCM. The combined organics were washed with brine and dried (MgSO 4 ), filtered and concentrated in-vacuo to give 9-[N-(6-carboxy-6- fluorohexyl)-4-(dimethylamino)butanamido]-2-fluorooctadecano ic acid (75 mg, 70.3%) which was used without purification. Step 8. Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{6-fluoro-7-oxo-7-[(3- pentyloctyl)oxy]heptyl}butanamido]-2-fluorooctadecanoate (34) 9-[N-(6-Carboxy-6-fluorohexyl)-4-(dimethylamino)butanamido]- 2-fluorooctadecanoic acid (75 mg, 0.13 mmol), 3-pentyloctan-1-ol (72 mg, 0.36 mmol), 2,4,6 trichlorobenzoyl chloride (95 g, 0.4 mmol) and DMAP (64 mg, 0.52 mmol) were stirred in in DCM (4 mL) at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in EtOAc, washed with NaHCO 3 (sat. soln.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH-DCM) to give 3- pentyloctyl 9-[4-(dimethylamino)-N-{6-fluoro-7-oxo-7-[(3- pentyloctyl)oxy]heptyl}butanamido]-2-fluorooctadecanoate (34) (42 mg, 34.3%). 1 H NMR (400 MHz, CDCl 3 ) δ 5.00 – 4.91 (m, 1H), 4.88 – 4.79 (m, 1H), 4.23 (qd, J = 6.2, 2.9 Hz, 4H), 3.71 – 3.56 (m, 1H), 3.07 (d, J = 8.3 Hz, 2H), 2.62 (s, 2H), 2.45 (m, 8H), 1.99 – 1.80 (m, 7H), 1.69 – 1.40 (m, 18H), 1.39 – 1.15 (m, 56H), 0.95 – 0.86 (m, 15H). Example 8. Synthesis of Synthesis of decyl 8-{N-[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-en- 1-yl]-5-(dimethylamino)pentanamido}octadecenoate (35) Step 1. Synthesis of (6Z,15Z)-henicosa-6,15-dien-11-ol A Grignard reagent was prepared from (4Z)-1-bromodec-4-ene (19.9 g, 91 mmol) and magnesium (2.4 g, 97.0 mmol) in THF. The reaction was heated at 45˚C for 3hr. After cooling to 10˚C, ethyl formate (7.0 g, 93.5 mmol in THF (35 mL) was added dropwise and the reaction stirred for 1 hr. Water (40 mL) and 6 M HCl (50 mL) were added to quench and the reaction partitioned between water and hexane. The organics were separated, washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was taken-up in EtOH (30 mL) and treated with a solution of KOH (4.6 g) in water (10 mL). After 5 min the EtOH was removed and the residue partitioned between hexane and 6 M HCl. The organics were washed with water and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% EtOAc-hexane) to give (6Z,15Z)-henicosa-6,15- dien-11-ol (11.4 g, 81.4%). Step 2. Synthesis of (6Z,15Z)-henicosa-6,15-dien-11-yl 4-methylbenzenesulfonate (6Z,15Z)-Henicosa-6,15-dien-11-ol (10 g, 32.4 mmol), TEA (9.0 mL, 64.8 mmol), trimethylammonium HCl (0.31 g, 3.2 mmol) and p toluenesulfonyl chloride (8.0 g, 42.1 mmol) were stirred in DCM (50 mL) at RT for 18 hr. The reaction was quenched slowly with N,N dimethyl propane diamine (1.09 g, 10.7 mmol). After stirring for 15 min the reaction was washed with water and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography to give (6Z,15Z)-henicosa-6,15-dien- 11-yl 4-methylbenzenesulfonate (0-5% EtOAc-hexane) (8.7 g, 57.9%). Step 3. Synthesis of (6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-enenitrile (6Z,15Z)-Henicosa-6,15-dien-11-yl 4-methylbenzenesulfonate (8.7 g, 18.8 mmol), dimethylimidazolidinone (22.6 mL, 0.83 M), acetone cyanohydrin (3.5 g, 41.5 mmol) and LiOH (880 mg, 36.6 mmol) were stirred in THF (52 mL) at 65˚C for 18 hr. The reaction was partitioned between EtOAc-hexane (1:1, 500 mL) and water, the organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-10% EtOAc-hexane) to give (6Z)-2-[(4Z)-dec-4-en-1- yl]dodec-6-enenitrile (4.9 g, 81.5 %). Step 4. Synthesis of yield (6Z,15Z)-11-(aminomethyl)henicosa-6,15-diene (6Z)-2-[(4Z)-Dec-4-en-1-yl]dodec-6-enenitrile (3.4 g, 9.9 mmol) and LiAlH4 (1.9 g, 50.0 mmol) were stirred in THF (75 mL) at 0˚C for 18 hr allowing to warm to RT. The reaction was cooled to 0˚C and quenched with 1M NaOH (1.9 mL). The mixture was dried (MgSO 4 ), filtered and concentrated in-vacuo and the crude material purified by automated flash chromatography (0-10% MeOH-DCM) to give (6Z,15Z)-11-(aminomethyl)henicosa-6,15-diene (2.4 g, 75.4%). Step 5. Synthesis of decyl 8-{[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-en-1- yl]amino}octadecenoate Decyl 8-oxooctadecanoate (368 mg, 0.84 mmol), (6Z,15Z)-11-(aminomethyl)henicosa- 6,15-diene (297 mg, 0.9 mmol), AcOH (0.1 mL, 1.7 mmol) and NaCNBH3 (156 mg, 2.5 mmol) were stirred in MeOH (10 mL) at (50˚C) for 18 hr. The reaction was concentrated in-vacuo, the residue taken-up in DCM, washed with NaHCO 3 (sat. soln) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (5-40% EtOAc-hexane) to give decyl 8-{[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-en-1- yl]amino}octadecanoate (438 mg, 70.2%). Step 6. decyl 8-{N-[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-en-1-yl]-5-(dimethy lamino)- pentanamido}octa decenoate 5-Dimethylamino]pentanoic acid, HCl salt (71 mg, 0.4 mmol), DCC (90 mg, 0.43 mmol) and DMAP (72 mg, 0.6 mmol) were stirred in MeCN (5 mL) at RT for 3 hr. Decyl 8-{[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec-6-en-1-yl]amino}octadec anoate (146 mg, 0.2 mmol) in DCM (2 mL) was added and the reaction stirred at RT for 18 hr. The reaction was concentrated in-vacuo, the residue dispersed in hexane:EtOAc:TEA (75:25:1), filtered through Celite and the filtrate concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-12% MeOH-DCM) to give decyl 8-{N-[(6Z)-2-[(4Z)-dec-4-en-1-yl]dodec- 6-en-1-yl]-5-(dimethylamino)pentanamido}octadecanoate (35) (88 mg, 51.5%). 1 H NMR (400 MHz, CDCl 3 ) δ 5.38 (hd, J = 7.9, 5.4 Hz, 4H), 4.07 (td, J = 6.8, 2.4 Hz, 2H), 3.63 (s, 1H), 3.09 (dd, J = 18.4, 7.5 Hz, 2H), 2.42 – 2.26 (m, 6H), 2.23 (d, J = 1.5 Hz, 6H), 2.01 (dd, J = 13.6, 6.8 Hz, 8H), 1.76 – 1.57 (m, 11H), 1.51 (dq, J = 14.7, 7.2 Hz, 5H), 1.43 – 1.17 (m, 53H), 0.96 – 0.84 (m, 12H). The following compounds were prepared using analogous methods as described above. Decyl 8-(N-((Z)-2-((Z)-dec-4-en-1-yl)dodec-6-en-1-yl)-4-(dimethyla mino)butanamido)- octadecenoate (36). 1 H NMR (400 MHz, CDCl 3 ) δ 5.48 – 5.25 (m, 4H), 4.07 (td, J = 6.8, 2.7 Hz, 2H), 3.66 (s, 1H), 3.09 (d, J = 7.5 Hz, 2H), 2.42 – 2.26 (m, 6H), 2.24 (s, 6H), 2.02 (t, J = 6.9 Hz, 7H), 1.82 (dt, J = 9.7, 7.2 Hz, 2H), 1.63 (d, J = 4.1 Hz, 9H), 1.47 (s, 2H), 1.41 – 1.18 (m, 53H), 0.97 – 0.84 (m, 12H). Decyl 8-(N-((Z)-2-((Z)-dec-4-en-1-yl)dodec-6-en-1-yl)-3-(dimethyla mino)propanamido)- octadecenoate (37). 1 H NMR (400 MHz, CDCl 3 ) δ 5.46 – 5.30 (m, 4H), 4.96 – 4.83 (m, 1H), 4.07 (td, J = 6.8, 2.0 Hz, 3H), 3.09 (d, J = 7.5 Hz, 2H), 2.75 – 2.61 (m, 3H), 2.60 – 2.45 (m, 3H), 2.35 – 2.23 (m, 9H), 2.03 (q, J = 6.5 Hz, 7H), 1.58 (d, J = 53.6 Hz, 20H), 1.43 – 1.19 (m, 57H), 0.91 (ddt, J = 6.9, 3.6, 2.3 Hz, 12H). Example 9. Synthesis of Synthesis of 3-pentyloctyl 9-[N-(decyloxy)-4- (dimethylamino)butanamido]-2-fluorooctadecanoate (38) Step 1. Synthesis of (decyloxy)[1-(oxan-2-yloxy)hexadecan-7-yl]amine 1-(Oxan-2-yloxy)hexadecan-7-one (7 g, 20.6 mmol), O-decylhydroxylamine (3.6 g, 21 mmol) and NaCNBH3 (3.9 g, 61.7 mmol) were stirred in THF (10 mL) at 50˚C for 16 hr. The reaction was concentrated in-vacuo, the residue dissolved in EtOAc and washed with water. The aqueous was back extracted with EtOAc and the combined organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% EtOAc/Hex) to give (decyloxy)[1-(oxan-2-yloxy)hexadecan-7- yl]amine (700 mg, 6.8%). Step 2. Synthesis of N-(decyloxy)-4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan- 7- yl]butanamide 4-(Dimethylamino)butanoic acid HCl salt (1.4 g, 8.0 mmol), HATU (3.1 g, 8.0 mmol) and DIPEA (4.2 mL, 24.1 mmol) were stirred in DCM (40 mL) at RT for 1 hr. (Decyloxy)[1-(oxan-2-yloxy)hexadecan-7-yl]amine (2 g, 4.0 mmol) in DCM (10 mL) was added and the reaction refluxed for 16 hr. After cooling to RT the reaction was washed sequentially with 1M HCl, sat NaHCO 3 , and brine, dried (MgSO 4 ), concentrated in-vacuo and the residue purified by automated flash chromatography (0-10% MeOH/DCM) to give N-(decyloxy)-4- (dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl]butanamide (2 g, 81.8%). Step 3. Synthesis of N-(decyloxy)-4-(dimethylamino)-N-(1-hydroxyhexadecan-7- yl)butanamide N-(Decyloxy)-4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan- 7-yl]butanamide (2.5 g, 4.1 mmol) and pTsOH-H 2 O (389 mg, 2.05 mmol) were stirred at RT in MeOH (10 mL) for 16 hr. The reaction was concentrated in-vacuo, the residue taken up in DCM, washed with sat NaHCO 3 and brine, dried (MgSO 4 ) and filtered. The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-20% MeOH/DCM) to give N- (decyloxy)-4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)buta namide (1.0 g, 46.4 %). Step 4. Synthesis of N-(decyloxy)-4-(dimethylamino)-N-(1-oxohexadecan-7-yl)butana mide N-(Decyloxy)-4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)bu tanamide (1.0 g, 1.9 mmol) and PCC-SiO2 (1:1) (3.3 g, 7.6 mmol) were stirred in DCM (10 mL) at RT for 16 hr. The reaction was filtered through silica and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-30% ACN/DCM) to give N-(decyloxy)-4-(dimethylamino)- N-(1-oxohexadecan-7-yl)butanamide (438 mg, 44.0 %). Step 5. Synthesis of ethyl (2Z)-9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2- fluorooctadec-2-enoate N-(Decyloxy)-4-(dimethylamino)-N-(1-oxohexadecan-7-yl)butana mide (438 mg, 0.8 mmol), ethyl 2-(diethoxyphosphoryl)-2-fluoroacetate (606 mg, 2.5 mmol) and DBU (381 mg, 2.5 mmol) were stirred at RT in THF (10 mL) for 16 hr. The solvent was removed in- vacuo, the residue taken up in EtOAc, washed with brine, and dried (MgSO 4 ). The filtrate was concentrated in-vacuo and purified by automated flash chromatography (0-20% ACN/DCM) to give ethyl (2Z)-9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooc tadec-2-enoate (512 mg, 100.0%). Step 6. Synthesis of crude ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2- fluorooctadecanoate Ethyl (2Z)-9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooc tadec-2-enoate (546 mg, 0.9 mmol) was subjected to catalytic hydrogenation over Pd-C in EtOAc (10 mL) at RT until complete. The reaction was filtered through Celite and concentrated in-vacuo to give ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoate which was used without purification. Step 7. Synthesis of 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoic acid Ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoate (548 mg, 0.9 mmol) and LiOH (85 mg, 3.6 mmol) were stirred in THF (10 mL) and H 2 O (1 mL) at RT for 16 hr. 6M HCl (0.9 mL) was added and the THF removed in-vacuo. The residue was taken up in DCM, washed with water the aqueous layer back extracted by DCM and the combined organics washed with brine. The organics were dried (MgSO 4 ), filtered and concentrated in- vacuo to give 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoic acid (390 mg, 74.6 %) which was used without purification. Step 8. Synthesis of 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2- 9-[N-(Decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoic acid (390 mg, 0.66 mmol), 3-pentyloctan-1-ol (0.2 g, 1.0 mmol), 2,4,6-trichlorobenzoyl chloride (324 mg, 1.33 mmol), TEA (81 mg, 0.8 mmol) and DMAP (106 mg, 0.86 mmol) were stirred in THF (6 mL) at RT for 1.5 hr. The reaction was filtered, concentrated in-vacuo and the residue purified by automated flash chromatography (0-100% DCM/Hex and 0-30% ACN/DCM) to give 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2-fluorooctadec anoate (38) (30 mg, 5.9 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.30 – 4.20 (m, 3H), 3.98 – 3.89 (m, 2H), 3.30 (d, J = 5.3 Hz, 2H), 2.97 (s, 6H), 2.93 – 2.88 (m, 2H), 2.29 – 2.09 (m, 2H), 2.09 – 1.58 (m, 8H), 1.56 – 0.92 (m, 56H), 0.95 – 0.75 (m, 12H). The following compounds were prepared using analogous methods as described above. Pentadecan-8-yl 9-(N-(decyloxy)-4-(dimethylamino)butanamido)-2-fluorooctadec anoate (111). 1 H NMR (400 MHz, CDCl 3 ) δ 5.05 – 4.90 (m, 1H), 4.81 (t, J = 5.9 Hz, 0H), 4.39 – 4.18 (m, 1H), 3.86 (t, J = 6.5 Hz, 2H), 2.48 (t, J = 7.5 Hz, 2H), 2.33 (t, J = 7.4 Hz, 2H), 2.25 (s, 6H), 1.94 – 1.77 (m, 4H), 1.69 – 1.53 (m, 11H), 1.45 (td, J = 13.9, 6.4 Hz, 5H), 1.29 (dd, J = 11.9, 6.1 Hz, 56H), 0.90 (t, J = 6.7 Hz, 12H). Example 10. Synthesis of 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]- 2,2-difluorononadecanoate (39) Step 1. Synthesis of (decyloxy)(heptadec-1-en-7-yl)amine Heptadec-1-en-7-one (5.2 g, 20.8 mmol), AcOH (2.4 mL, 42 mmol) and NaCNBH3 (4.0 g, 62.0 mmol) were stirred in THF (60 mL) at 50˚C for 15 hr. The solvent was removed in- vacuo and the residue partitioned between H 2 0 (50 mL) and DCM (50 mL). The aqueous layer was further extracted with DCM, the combined organics dried (Na2SO 4 ) concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% EtOAc/Hex) to give (decyloxy)(heptadec-1-en-7-yl)amine (4.04 g, 47.5 %). Step 2. Synthesis of N-(decyloxy)-4-(dimethylamino)-N-(heptadec-1-en-7-yl)butanam ide 4-(Dimethylamino)butanoic acid HCl salt (3.3 g, 19.5 mmol), HATU (7.4 g, 19.5 mmol) and DIPEA (7.6 g, 58.6 mmol) were stirred in DCM (40 mL) at RT for 1 hr. (Decyloxy)(heptadec-1-en-7-yl)amine (4 g, 9.8 mmol) in DCM (10 mL) was added and the reaction heated at reflux for 16 hr. After cooling the reaction was washed sequentially with 1M HCl, sat NaHCO 3 and brine, dried (MgSO 4 ), filtered and the filtrate concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% MeOH/DCM) to give N- (decyloxy)-4-(dimethylamino)-N-(heptadec-1-en-7-yl)butanamid e (4.1 g, 80.3 %). Step 3. Synthesis of ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2- difluorononadecanoate In a vacuum dried flask, Hantsch ester (2.0 g, 7.7 mmol), NaOAc (4.9 g, 15.3 mmol), AgOTf (4.9 g, 19.1 mmol) and iodobenzene diacetate (4.9 g, 15.3 mmol) were stirred under nitrogen in NMP (30 mL). N-(Decyloxy)-4-(dimethylamino)-N-(heptadec-1-en-7- yl)butanamide (4 g, 7.7 mmol) in NMP (30 mL) and ethyl 2,2-difluoro-2-(trimethylsilyl)acetate (7.5 g, 38.3 mmol) were added and the reaction was stirred at RT for 18 hr. The reaction was filtered through Celite and the filtrate washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0- 50% ACN/DCM) to give ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2- difluorononadecanoate (3.2 g, 64.7 %). Step 4. Synthesis of 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2- Ethyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2-difluoronon adecanoate (731 mg, 1.1 mmol) and LiOH (108 mg, 4.5 mmol) were stirred in THF (10 mL) and water (2 mL) at RT until complete. The reaction was quenched with 6M HCl (0.75 mL) and partially concentrated in-vacuo. The reaction was diluted with DCM, washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo azeotroping with toluene (25 mL). The crude carboxylic acid, 3-pentyloctan-1-ol (0.34 g, 1.7 mmol), 2,4,6-trichlorobenzoyl chloride (0.6 g, 2.3 mmol), TEA (137 mg, 1.4 mmol) and DMAP (179 mg, 1.5 mmol) were stirred in THF (6 mL) RT for 1.5 hr. The reaction was concentrated in-vacuo and the crude material purified by automated flash chromatography (0-100% DCM/Hex and 0-15% ACN/DCM) to give a mixture of 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2-difluoronon adecanoate and an unsaturated impurity.The mixture was subjected to catalytic hydrogenation over Pd-C in EtOAc (10 mL) at RT for 1 hr. The reaction was filtered through celite and concentrated in-vacuo to give 3-pentyloctyl 9-[N-(decyloxy)-4-(dimethylamino)butanamido]-2,2-difluoronon adecanoate (39) (371 mg, 41.0 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.30 (t, J = 7.1 Hz, 2H), 4.24 (dd, J = 9.5, 4.6 Hz, 1H), 3.99 – 3.92 (m, 2H), 3.30 (dd, J = 12.4, 7.1 Hz, 2H), 2.98 (s, 6H), 2.92 (dd, J = 7.3, 4.3 Hz, 2H), 2.04 (dt, J = 11.6, 6.4 Hz, 4H), 1.74 – 1.61 (m, 6H), 1.53 – 1.19 (m, 57H), 0.94 – 0.87 (zm, 12H). The following compound was prepared using analogous methodology as described above. Pentadecan-8-yl 9-(N-(decyloxy)-4-(dimethylamino)butanamido)-2,2-difluoro- nonadecanoate (106). 1 H NMR (400 MHz, CDCl 3 ) δ 7.31, 7.28, 5.32, 5.03, 5.02, 5.00, 4.30, 3.88, 3.86, 3.84, 2.50, 2.48, 2.46, 2.34, 2.32, 2.30, 2.25, 2.07, 2.05, 2.03, 2.01, 1.99, 1.87, 1.85, 1.83, 1.81, 1.64, 1.62, 1.60, 1.58, 1.47, 1.30, 1.29, 1.27, 0.92, 0.91, 0.90, 0.88. Example 11. Synthesis of Synthesis of 3-{N-[3-(dimethylamino)propyl]decanamido}- dodecyl 2-fluoro-2-hexyldecanoate (40) Step 1. Synthesis of 3-{[3-(dimethylamino)propyl]amino}dodecan-1-ol LiAlH4 (1.7 g, 26.8 mmol) was stirred in THF (100 mL) at 0˚C. Methyl 3-{[3- (dimethylamino)propyl]amino}dodecanoate (2.8 g, 8.9 mmol) in THF (100 mL) was added dropwise and the reaction stirred at RT until complete. The reaction was cooled to 0˚C, 1M NaOH (20 mL) added and extracted with EtOAc. The organics were dried (MgSO 4 ), filtered, and the filtrate concentrated in-vacuo to give crude 3-{[3- (dimethylamino)propyl]amino}dodecan-1-ol (2.6 g, 100.0 %), which was used without purification. Step 2. Synthesis of benzyl N-[3-(dimethylamino)propyl]-N-(1-hydroxydodecan-3- yl)carbamate 3-{[3-(Dimethylamino)propyl]amino}dodecan-1-ol (2.6 g, 8.9 mmol) and benzyl 2,5- dioxopyrrolidin-1-yl carbonate (2.2 g, 8.9 mmol) were stirred in DCM (50 mL) at 0˚C for 16 hr allowing to warm to RT. The reaction was concentrated in-vacuo and the residue purified by automated flash chromatography (0-20% MeOH/DCM) to give benzyl N-[3- (dimethylamino)propyl]-N-(1-hydroxydodecan-3-yl)carbamate (2.1 g, 56.0 %) Step 3. Synthesis of 3-{[(benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec yl 2- fluoro-2-hexyldecanoate Benzyl N-[3-(dimethylamino)propyl]-N-(1-hydroxydodecan-3-yl)carbama te (230 mg, 0.5 mmol), 2-fluoro-2-hexyldecanoyl chloride (160 mg, 0.5 mmol) and DIPEA (0.2 mL, 1.1 mmol) were heated in DCM 80˚C for 10 min under microwave irradiation. The reaction was concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% MeOH/DCM) to give 3-{[(benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec yl 2- fluoro-2-hexyldecanoate (196 mg, 53.0 %). Step 4. Synthesis of 3-{[3-(dimethylamino)propyl]amino}dodecyl 2-fluoro-2- hexyldecanoate 3-{[(Benzyloxy)carbonyl][3-(dimethylamino)propyl]amino}dodec yl 2-fluoro-2- hexyldecanoate (196 mg, 0.3 mmol) was subjected to catalytic hydrogenation over Pd/C in MeOH at RT for 16 h. The reaction was filtered and concentrated in-vacuo to give 3-{[3- (dimethylamino)propyl]amino}dodecyl 2-fluoro-2-hexyldecanoate (157 mg, 99.9%) which was used without further purification. Step 5. Synthesis of 3-{N-[3-(dimethylamino)propyl]decanamido}dodecyl 2-fluoro-2- hexyldecanoate (40) 3-{[3-(Dimethylamino)propyl]amino}dodecyl 2-fluoro-2-hexyldecanoate (157 mg, 0.3 mmol), decanoyl chloride (61 mg, 0.32 mmol) and TEA (59 mg, 0.6 mmol) were refluxed in DCM (20 mL) for 24 hr. After cooling the reaction was washed with NaHCO 3 , brine, dried (MgSO 4 ) and filtered. The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-10% MeOH/DCM) to give 3-{N-[3- (dimethylamino)propyl]decanamido}dodecyl 2-fluoro-2-hexyldecanoate (40) (64 mg, 31.7%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.41 – 4.34 (m, 1H), 4.23 – 4.16 (m, 1H), 4.12 – 4.05 (m, 1H), 4.01 – 3.94 (m, 1H), 3.93 – 3.85 (m, 1H), 3.78 – 3.71 (m, 1H), 3.24 – 3.15 (m, 2H), 2.39 – 2.23 (m, 7H), 1.96 – 1.72 (m, 8H), 1.51 (d, J = 7.4 Hz, 8H), 1.39 – 1.08 (m, 42H), 0.90 (t, 12H). Example 12. Synthesis of Synthesis of 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3- (dimethylamino)propoxy]-8-oxooctanamido}octadecenoate (41) Step 1. Synthesis of 2-butyloctyl 8-chloro-8-oxooctanoate 8-[(2-Butyloctyl)oxy]-8-oxooctanoic acid (120 mg, 0.35 mmol), oxalyl chloride (67 mg, 0.53 mmol) and DMF (cat) were stirred in DCM at RT for 3 hr. The reaction was concentrated in-vacuo and the residue dried under vacuum to give 2-butyloctyl 8-chloro-8-oxooctanoate (126 mg, 99.6%) which was used without purification. Step 2. Synthesis of 2-hexyldecyl 8-{[3-(dimethylamino)propoxy]amino}octadecenoate [3-(Dimethylamino)propoxy]amine (HCl salt) (148 mg, 1.0 mmol), 2-hexyldecyl 8- oxooctadecanoate (500 mg, 1.0 mmol), AcOH (115 mg, 1.9 mmol) and NaCNBH3 (180 mg, 2.9 mmol) were stirred in MeOH (8 mL) at 45˚C for 3 days. The reaction was concentrated in- vacuo and the residue partitioned between 1:1 DCM/H 2 O. The aqueous was further extracted with DCM and the organics washed with brine, dried MgSO 4 , filtered and concentrated in- vacuo. The residue was purified by automated flash chromatography (0-15% MeOH/DCM) to give 2-hexyldecyl 8-{[3-(dimethylamino)propoxy]amino}octadecanoate (385 mg, 64.4 %). Step 3. Synthesis of 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3-(dimethylamino)propoxy]- 8-oxooctanamido}octadecenoate (41) 2-Hexyldecyl 8-{[3-(dimethylamino)propoxy]amino}octadecanoate (192 mg, 0.31 mmol) and TEA (62 mg, 0.6 mmol) was stirred in DCM at RT.2-Butyloctyl 8-chloro-8- oxooctanoate (133 mg, 0.37 mmol,) in DCM was added and the reaction stirred at RT for 18 hr. The organics were washed with sat. NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated In-vacuo. The crude material was purified by automated flash chromatography (0- 15% MeOH/DCM) to give 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3- (dimethylamino)propoxy]-8-oxooctanamido}octadecanoate (41) (88 mg, 30.2%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.32 – 4.24 (m, 1H), 3.99 (m, 4H), 3.93 – 3.89 (m, 2H), 2.53 – 2.13 (m, 14H), 1.60 – 1.42 (m, 14H), 1.43 – 1.02 (m, 66H), 0.94 – 0.85 (m, 15H). Example 13. Synthesis of 2-hexyldecyl 7-{N-[3-(dimethylamino)propoxy]decanamido}- heptadecanoate (42) 2-Hexyldecyl 7-{[3-(dimethylamino)propoxy]amino}heptadecanoate (133 mg, 0.22 mmol) and TEA (44 mg, 0.44 mmol) were stirred in DCM (3 mL) at RT. Decanoyl chloride (5 mg, 0.26 mmol) in DCM was added dropwise. The reaction was stirred at RT for 18 hr. The organics were washed with sat NaHCO 3 solution and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude product was purified by automated flash chromatography (0- 10% MeOH/DCM) to give 2-hexyldecyl 7-{N-[3- (dimethylamino)propoxy]decanamido}heptadecanoate (42) (51 mg, 30.6%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.30 (s, 2H), 3.98 (d, J = 5.8 Hz, 2H), 3.92 (s, 1H), 2.57 – 2.19 (m, 12H), 1.87 – 1.81 (m, 2H), 1.65 – 1.56 (m, 11H), 1.48 – 1.42 (s, 3H), 1.38 – 1.17 (m, 51H), 0.90 (td, J = 6.9, 1.8 Hz, 12H). Example 14. Synthesis of 8-[N-(decyloxy)-4-(dimethylamino)butanamido]- octadecenoate (43) Step 1. Synthesis of 3-pentyloctyl 8-[(decyloxy)amino]octadecenoate 3-Pentyloctyl 8-oxooctadecanoate (13.3 g, 28 mmol), O-decylhydroxylamine (7.2 g, 41.5 mmol) AcOH (3.2 mL, 55 mmol) and NaCNBH3 (5.2 g, 83 mmol) were stirred in MeOH (100 mL) and DCE (50 mL) at 50˚C for 15 hr. Additional NaCNBH3 (1eq) was added and the reaction stirred at 60˚C for 72 hr. The reaction was concentrated in-vacuo, and the residue partitioned between H 2 O (50 mL) and DCM (50 mL). The aqueous layer extracted with DCM and the combined organics dried MgSO 4 , filtered, concentrated in-vacuo and the residue purified by automated flash chromatography to give 3-pentyloctyl 8-[(decyloxy)amino]octadecanoate (18 g, 28.2 mmol, Quant). Step 2. Synthesis of 3-pentyloctyl 8-[N-(decyloxy)-4-(dimethylamino)butanamido]- octadecenoate (43) 3-Pentyloctyl 8-[(decyloxy)amino]octadecanoate (16.21g, 25.4 mmol), 4- (dimethylamino)butane carboxylic acid HCl salt (4.7 g, 27.9 mmol), DIPEA (10.8 g, 83.8 mmol) and PyBOP (14.5 g, 27.9 mmol) were stirred in DCM (50 mL) at RT for 18 hr. The reaction was washed with 1M HCl, NaHCO 3 (sat. aq.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified with automated flash chromatography (0-15% MeOH/DCM) to give 3-pentyloctyl 8-[N-(decyloxy)-4- (dimethylamino)butanamido]octadecanoate which was taken up in EtOAc, washed with sat NaHCO 3 (3 ×) and 1M NaOH (2 ×) twice, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 8-[N-(decyloxy)-4-(dimethylamino)butanamido]octadecanoate (43) (6.4 g, 33.5 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.25 (tt, J = 9.9, 5.0 Hz, 1H), 4.05 (t, J = 7.1 Hz, 2H), 3.81 (t, J = 6.5 Hz, 2H), 2.43 (t, J = 7.5 Hz, 2H), 2.26 (dt, J = 17.2, 7.4 Hz, 4H), 2.20 (s, 6H), 1.78 (p, J = 7.4 Hz, 2H), 1.56 (dq, J = 20.5, 6.6 Hz, 8H), 1.47 – 1.33 (m, 5H), 1.24 (dd, J = 13.4, 4.8 Hz, 50H), 0.85 (td, J = 6.9, 3.0 Hz, 12H). The following compounds were prepared using analogous methodology as described above. 2-Hexyldecyl 7-(N-(decyloxy)-4-(dimethylamino)butanamido)heptadecanoate (44). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (s, 1H), 3.98 (d, J = 5.8 Hz, 2H), 3.86 (t, J = 6.5 Hz, 2H), 2.55 – 2.21 (m, 10H), 1.61-1.90 (m, 19H), 1.29 (m, 48H), 0.99 – 0.73 (m, 12H). 2-Hexyldecyl 8-(N-(decyloxy)-5-(dimethylamino)pentanamido)octadecenoate (45). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (s, 1H), 3.98 (d, J = 5.8 Hz, 2H), 3.85 (t, J = 6.5 Hz, 2H), 2.47 (t, J = 7.2 Hz, 2H), 2.38 (s, 2H), 2.29 (d, J = 7.8 Hz, 6H), 1.84 – 1.52 (m, 22H), 1.52 – 1.06 (m, 53H), 0.90 (td, J = 6.9, 2.0 Hz, 12H). 2-Hexyldecyl 8-(N-(decyloxy)-4-(dimethylamino)butanamido)octadecenoate (46). 1 H NMR (400 MHz, CDCl 3 ) δ 4.28 (s, 1H), 3.98 (d, J = 5.8 Hz, 2H), 3.86 (t, J = 6.6 Hz, 2H), 2.51 (t, J = 7.3 Hz, 3H), 2.30 (t, J = 7.5 Hz, 4H), 1.96 – 1.83 (m, 2H), 1.63 (d, J = 16.9 Hz, 22H), 1.54 – 1.22 (m, 52H), 0.90 (td, J = 6.8, 2.1 Hz, 12H). 2-Hexyldecyl 7-(N-(decyloxy)-5-(dimethylamino)pentanamido)heptadecanoate (47). Product confirmed by MS (ESI +ve) 3-Pentyloctyl (Z)-8-(N-(dec-3-en-1-yloxy)-5-(dimethylamino)pentanamido)oct adecanoate (94). 1 H NMR (400 MHz, CDCl 3 ) δ 5.51 – 5.30 (m, 2H), 4.39 – 4.19 (m, 1H), 4.10 (t, J = 7.1 Hz, 2H), 3.86 (t, J = 6.6 Hz, 2H), 2.47 (t, J = 7.3 Hz, 2H), 2.40 – 2.24 (m, 10H), 2.05 (dd, J = 13.8, 6.7 Hz, 2H), 1.95 (s, 7H), 1.76 – 1.49 (m, 7H), 1.44 – 1.20 (m, 44H), 0.91 (ddt, J = 7.0, 5.3, 2.6 Hz, 12H). 3-Pentyloctyl 8-(N-(decyloxy)-5-(dimethylamino)pentanamido)octadecanoate (95). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (d, J = 4.9 Hz, 0H), 4.10 (t, J = 7.1 Hz, 2H), 3.85 (t, J = 6.5 Hz, 2H), 2.47 (t, J = 7.4 Hz, 2H), 2.34 (dd, J = 16.2, 8.8 Hz, 3H), 2.29 (d, J = 5.3 Hz, 7H), 1.74 – 1.51 (m, 20H), 1.51 – 1.14 (m, 57H), 0.90 (td, J = 6.9, 2.6 Hz, 12H). 3-Hexylnonyl (Z)-8-(N-(dec-3-en-1-yloxy)-5-(dimethylamino)pentanamido)oct adecanoate (96). 1 H NMR (400 MHz, CDCl 3 ) δ 5.50 – 5.31 (m, 2H), 4.29 (s, 1H), 4.10 (t, J = 7.1 Hz, 2H), 3.86 (t, J = 6.6 Hz, 2H), 2.47 (t, J = 7.4 Hz, 2H), 2.37 – 2.23 (m, 10H), 2.16 (q, J = 7.4 Hz, 2H), 2.05 (q, J = 7.1 Hz, 2H), 1.76 – 1.54 (m, 20H), 1.52 – 1.15 (m, 47H), 0.91 (tt, J = 6.8, 2.8 Hz, 12H). 3-Hexylnonyl 8-(N-(decyloxy)-5-(dimethylamino)pentanamido)octadecanoate (97). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (d, J = 5.1 Hz, 0H), 4.10 (t, J = 7.1 Hz, 2H), 3.85 (t, J = 6.6 Hz, 2H), 2.47 (t, J = 7.4 Hz, 2H), 2.38 – 2.22 (m, 9H), 1.74 – 1.51 (m, 17H), 1.50 – 1.19 (m, 57H), 0.90 3-Heptyldecyl (Z)-8-(N-(dec-3-en-1-yloxy)-5-(dimethylamino)pentanamido)oct adecanoate (98). 1 H NMR (400 MHz, CDCl 3 ) δ 5.51 – 5.31 (m, 2H), 4.29 (s, 1H), 4.09 (t, J = 7.1 Hz, 2H), 3.86 (t, J = 6.6 Hz, 2H), 2.48 (t, J = 7.2 Hz, 2H), 2.44 – 2.23 (m, 9H), 2.17 (q, J = 7.5 Hz, 2H), 1.77 – 1.18 (m, 70H), 0.90 (td, J = 6.7, 2.3 Hz, 12H). 3-Heptyldecyl 8-(N-(decyloxy)-5-(dimethylamino)pentanamido)octadecanoate. (99). 1 H NMR (400 MHz, CDCl 3 ) δ 4.29 (s, 1H), 4.09 (t, J = 7.1 Hz, 2H), 3.85 (t, J = 6.5 Hz, 2H), 2.68 – 2.14 (m, 12H), 1.63 (tq, J = 13.9, 7.3 Hz, 21H), 1.53 – 1.16 (m, 60H), 1.00 – 0.79 (m, 12H). 3-Pentyloctyl (Z)-8-(N-(dec-3-en-1-yloxy)-4-(dimethylamino)butanamido)octa decanoate (100). 1 H NMR (400 MHz, CDCl 3 ) δ 5.50 – 5.31 (m, 2H), 4.29 (s, 0H), 4.10 (t, J = 7.1 Hz, 2H), 3.87 (t, J = 6.6 Hz, 2H), 2.50 (t, J = 7.4 Hz, 2H), 2.40 (s, 2H), 2.33 – 2.27 (m, 7H), 2.16 (q, J = 7.4 Hz, 2H), 2.05 (q, J = 7.0 Hz, 2H), 1.87 (p, J = 7.4 Hz, 2H), 1.77 – 1.54 (m, 16H), 1.29 (d, J = 13.9 Hz, 42H), 0.91 (tt, J = 6.9, 2.8 Hz, 12H). Example 15. Synthesis of 2-hexyldecyl 3-{N-[3-(dimethylamino)propyl]octane-1- sulfonamido}dodecanoate (48) Step 1. Synthesis of methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate Methyl 3-oxododecanoate (5 g, 21.9 mmol), dimethylaminopropylamine (2.2 g, 21.9 mmol) and AcOH (1.4 g, 22.6 mmol) were stirred in MeOH (100 mL) at 75˚C for 1 hr. After cooling NaCNBH3 (2.8 g, 43.8 mmol was added in portions and the reaction stirred at RT for 18 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc, washed with H 2 O and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified with automated flash chromatography (0-10% MeOH/DCM/0.5% TEA) to give methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (2.62 g, 38.0 %). Step 2. Synthesis of methyl 3-{N-[3-(dimethylamino)propyl]octane-1- sulfonamido}dodecanoate Methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (300 mg, 1.0 mmol), TEA (193 mg, 1.9 mmol) and 1-octanesulfonyl chloride (213 mg, 1.0 mmol) were stirred in DCM at RT for 18 hr. The organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in- vacuo. The residue was purified by automated flash chromatography (0-5% MeOH/DCM) to give methyl 3-{N-[3-(dimethylamino)propyl]octane-1-sulfonamido}dodecanoa te (276 mg, 59.0%). Step 3. Synthesis of 3-{N-[3-(dimethylamino)propyl]octane-1-sulfonamido}dodecanoi c Methyl 3-{N-[3-(dimethylamino)propyl]octane-1-sulfonamido}dodecanoa te (278 mg, 0.6 mmol) and LiOH (27 mg, 1.1 mmol) were stirred in MeOH (10 mL) and H 2 O (2 mL) at RT for 18 hr.6M HCl (0.19 mL, 6 M, 1.1 mmol) was added, the reaction diluted with water and extracted with DCM. The organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-{N-[3-(dimethylamino)propyl]octane-1-sulfonamido}dodecanoi c acid (0.27 g, Quant), which was used without purification. Step 4. Synthesis of 2-hexyldecyl 3-{N-[3-(dimethylamino)propyl]octane-1- sulfonamido}dodecanoate (48) 3-{N-[3-(Dimethylamino)propyl]octane-1-sulfonamido}dodecanoi c acid (0.27 g, 0.6 mmol), hexyldecanol (151 mg, 0.6 mmol), EDC HCl (217 mg, 1.1 mmol), DIPEA (0.3 mL, 1.7 mmol) and DMAP (cat) were stirred at RT for 18 hr. The organics were washed with sat NaHCO 3 and brine, dried (MgSO 4 ) filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-12% MeOH/DCM) and (0-2% MeOH/EtOAc) to give 2- hexyldecyl 3-{N-[3-(dimethylamino)propyl]octane-1-sulfonamido}dodecanoa te (48) (61 mg, 15.4%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.05 – 4.00 (m, 3H), 3.25 – 3.14 (m, 2H), 2.95 (td, J = 7.0, 3.2 Hz, 2H), 2.71 – 2.53 (m, 2H), 2.32 – 2.24 (m, 7H), 1.91 – 1.58 (m, 12H), 1.43 – 1.28 (m, 44H), 0.93– 0.75 (m, 12H). The following compound was prepared using analogous methodology as described above. 2-Hexyldecyl 3-(N-(3-(dimethylamino)propyl)butylsulfonamido)dodecanoate (49). Product confirmed by MS (ESI +ve) Example 16. Synthesis of Decyl 3-{N-[3-(dimethylamino)propyl]2- hexyldecanesulfonamido}dodecanoate (50) Step 1. Synthesis of 2-hexyldecyl methanesulfonate Hexyldecanol (2 g, 8.2 mmol) and TEA (1.44 mL, 10.3 mmol) were stirred in DCM (30 mL) at 0˚C. MsCl (0.7 mL, 9.1 mmol) was added dropwise and the reaction stirred at RT for 2 hr. The reaction was quenched with sat NaHCO 3 and diluted with Et 2 O.The organics were washed with brine, dried (MgSO 4 ) and concentrated in-vacuo to give crude 2-hexyldecyl methanesulfonate (2.64 g, Quant) which was used without purification. Step 2. Synthesis of 7-(bromomethyl)pentadecane 2-Hexyldecyl methanesulfonate (2.64 g, 8.2 mmol) and TBAB (3.5 g, 10.7 mmol) were stirred in methyl THF (50 mL) at 80˚C for 2.5 hr. The reaction was poured into ice water and extracted with hexane. The aqueous layer was back extracted with hexane and the combined organics washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (100% Hexane) to give 7- (bromomethyl)pentadecane (2.52 g, 95.2%). Step 3. Synthesis of 2-hexyldecane-1-sulfonyl chloride 7-(Bromomethyl)pentadecane (500 mg, 1.64 mmol) and thiourea (124 mg, 1.64 mmol) were refluxed in EtOH (10 mL) for 1 hr. The solvent was removed in-vacuo and the residue stirred with chlorosuccinimide (1.1 g, 8.2 mmol), 2M HCl (1.1 mL, 1.1 mmol) and MeCN (10 mL) maintaining the temperature between 10 and 20°C for 15 min. The reaction was partitioned between Et 2 O (15 mL) and H 2 O (15 mL). The organics were separated, dried (Na2SO 4 ), concentrated in-vacuo and the crude purified by automated flash chromatography (PE–EtOAc, 5:1) to give 2-hexyldecane-1-sulfonyl chloride (436 mg, 82.0 %). Step 4. Synthesis of methyl 3-{N-[3-(dimethylamino)propyl]2-hexyldecanesulfonamido}- dodecanoate Methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (426 mg, 1.4 mmol) TEA (380 µL, 2.7 mmol) and 2-hexyldecane-1-sulfonyl chloride (462 mg, 1.4 mmol) were stirred in DCM (10 mL) at RT for 2 days. The organics were washed with brine, dried (MgSO 4 ), filtered, the filtrate concentrated in-vacuo and the residue purified by automated flash chromatography (0-10% MeOH/DCM) to give methyl 3-{N-[3-(dimethylamino)propyl]2- hexyldecanesulfonamido}dodecanoate (366 mg, 44.8%). Step 5. Synthesis of 3-{N-[3-(dimethylamino)propyl]2-hexyldecanesulfonamido}- dodecanoic acid Methyl 3-{N-[3-(dimethylamino)propyl]2-hexyldecanesulfonamido}dodec anoate (366 mg, 0.61 mmol) and LiOH (29 mg, 1.2 mmol) were stirred in MeOH (10 mL) and H 2 O (2 mL) at RT for 18 hr. The reaction was quenched with 6 M HCl (0.2 mL), diluted with H 2 O and extracted with DCM. The organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-{N-[3-(dimethylamino)propyl]2-hexyldecanesulfonamido}dodec anoic acid (291 mg, 81.4 %) which was used without further purification. Step 6. Synthesis of decyl 3-{N-[3-(dimethylamino)propyl]2-hexyldecane- sulfonamido}dodecanoate (50) Decanol (86 mg, 0.54 mmol), 3-{N-[3-(dimethylamino)propyl]2-hexyldecane- sulfonamido}dodecanoic acid (291 mg, 0.5 mmol), EDC HCl (189 mg, 1.0 mmol), DIPEA (0.26 mL, 1.5 mmol) and DMAP (6 mg, 0.05 mmol) were stirred in DCM (2 mL) at RT for 18 hr. The organics were washed with sat NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated under in-vacuo. The residue was purified by automated flash chromatography (0- 2% MeOH/EtOAc) twice, to give decyl 3-{N-[3-(dimethylamino)propyl]2-hexyldecane- sulfonamido}dodecanoate (50) (41mg, 11.4%) . 1 H NMR (400 MHz, CDCl 3 ) δ 4.11 - 4.04 (m, 3H), 3.20 - 3.14 (m, 2H), 2.91 (dd, J = 13.7, 6.2 Hz, 1H), 2.80 (dd, J = 13.7, 6.1 Hz, 1H), 2.65 (dd, J = 15.4, 7.1 Hz, 1H), 2.55 (dd, J = 15.5, 6.9 Hz, 1H), 2.31 - 2.23 (m, 7H), 2.08 - 2.02 (m, 1H), 1.84 - 1.63 (m, 10H), 1.42-1.49 (m, 5H), 1.49 - 1.28 (m, 44H), 0.90 (t, J = 6.6 Hz, 12H). Example 17. Synthesis of 3-{N-[3-(dimethylamino)propyl]undecane-1- sulfonamido}dodecanoate (51) Step 1. Synthesis of methyl 3-{N-[3-(dimethylamino)propyl]undecane-1- sulfonamido}dodecanoate Methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (939 mg, 3.0 mmol) TEA (0.8 mL, 6.0 mmol) and undecane-1-sulfonyl chloride (989 mg, 3.9 mmol) were stirred in DCM (30 mL) at RT for 18 hr. The organics were washed with brine, dried (MgSO 4 ), filtered and the filtrate was concentrated in-vacuo The residue was purified by automated flash chromatography (0-10% MeOH/DCM) to give methyl 3-{N-[3-(dimethylamino)propyl]undecane-1- sulfonamido}dodecanoate (564 mg, 35.5%). Step 2. Synthesis of 3-{N-[3-(dimethylamino)propyl]undecane-1-sulfonamido}dodecan oic acid Methyl 3-{N-[3-(dimethylamino)propyl]undecane-1-sulfonamido}dodecan oate (564 mg, 1.1 mmol) and LiOH (76 mg, 3.2 mmol) were stirred in MeOH (10 mL) and H 2 O (2 mL) at RT for 18 hr.6M HCl (0.53 mL,) was added, the reaction diluted with H 2 O and extracted with DCM. The organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-{N-[3- (dimethylamino)propyl]undecane-1-sulfonamido}dodecanoic acid , which was used without purification. Step 3. Synthesis of 2-hexyldecyl 3-{N-[3-(dimethylamino)propyl]undecane-1- sulfonamido}dodecanoate (51) Hexyldecanol (139 mg, 0.6 mmol), 3-{N-[3-(dimethylamino)propyl]undecane-1- sulfonamido}dodecanoic acid (270 mg, 0.52 mmol), EDC HCl (0.2 g, 1.04 mmol), DIPEA (202 mg, 0.3 mL, 1.56 mmol) and DMAP (13 mg, 0.1 mmol) were stirred in DCM (10 mL) at RT for 18 hr. the organics were washed with sat NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-4% MeOH/EtOAc and 0-10% MeOH/DCM) to give 2-hexyldecyl 3-{N-[3- (dimethylamino)propyl]undecane-1-sulfonamido}dodecanoate (51) (50 mg, 13.0%) . 1 H NMR (400 MHz, CDCl 3 ) δ 4.08 – 3.89 (m, 3H), 3.29 – 3.08 (m, 2H), 3.01 – 2.83 (m, 2H), 2.72 – 2.47 (m, 2H), 2.33 – 2.09 (m, 7H), 1.86 – 1.45 (m, 10H), 1.44 – 0.94 (m, 52H), 0.87 (t, J = 6.5 Hz, 12H). The following compound was prepared using analogous methodology as described above (Z)-Dec-4-en-1-yl 3-(N-(3-(dimethylamino)propyl)undecylsulfonamido)dodecanoate (52). 1 H NMR (400 MHz, CDCl 3 ) δ 5.46 – 5.26 (m, 2H), 4.15 – 3.91 (m, 3H), 3.23 – 3.06 (m, 2H), 3.01 – 2.82 (m, 2H), 2.70 – 2.46 (m, 2H), 2.35 – 2.13 (m, 7H), 2.05 (dq, J = 35.5, 7.2 Hz, 4H), 1.89 – 1.45 (m, 10H), 1.44 – 0.99 (m, 35H), 0.94 – 0.80 (m, 9H). Example 18. Synthesis of N-[3-(dimethylamino)propyl]-N-[1-(N',N'- dioctylhydrazinecarbonyl)undecan-2-yl]decanamide (53) Step 1. Synthesis of methyl 3-{N-[3-(dimethylamino)propyl]decanamido}dodecanoate Methyl 3-{[3-(dimethylamino)propyl]amino}dodecanoate (2 g, 6.4 mmol) and TEA (4.6 mL, 12.7 mmol)) were stirred in DCM at RT. Decanoyl chloride (1.3 g, 7.0 mmol) was added dropwise and the reaction stirred at RT for 18 hr. The organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by (0-10% MeOH/DCM) to give methyl 3-{N-[3-(dimethylamino)propyl]decanamido}dodecanoate (2 g, 67.4%). Step 2. Synthesis of 3-{N-[3-(dimethylamino)propyl]decanamido}dodecanoic acid Methyl 3-{N-[3-(dimethylamino)propyl]decanamido}dodecanoate (3.4 g, 7.3 mmol) and LiOH (347 mg, 14.5 mmol) were stirred in MeOH (8 mL) and H 2 O (2 mL) at RT for 18 hr.6 M HCl (2.4 mL) was added and the reaction extracted with DCM. The organics were combined, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 3-{N-[3- (dimethylamino)propyl]decanamido}dodecanoic acid (3.03 g, 91.9%) which was used without purification. Step 3. Synthesis of N-[3-(dimethylamino)propyl]-N-[1-(N',N'-dioctylhydrazine- carbonyl)undecan-2-yl]decanamide (53) 1,1-Dioctylhydrazine (782 mg, 3.0 mmol), 3-{N-[3-(dimethylamino)propyl]- decanamido}dodecanoic acid (1.5 g, 3.35 mmol), EDC HCl (1.17 g, 6.1 mmol) and DMAP (37 mg, 0.31 mmol) were stirred in DCM at RT for 16 hr. The reaction was quenched with sat. NaHCO 3 , extracted with DCM, the organics washed with brine, dried (MgSO 4 ) and concentrated in-vacuo. The residue was purified by automated flash chromatography (5% MeOH/DCM) to give N-[3-(dimethylamino)propyl]-N-[1-(N',N'-dioctylhydrazinecarb onyl)undecan-2- yl]decanamide (53) (495 mg, 23.4 %). 1 H NMR (400 MHz, CDCl 3 ) δ 5.74 (s, 1H), 3.32 – 3.07 (m, 2H), 2.83 – 2.55 (m, 5H), 2.55 – 2.14 (m, 12H), 1.79 – 1.64 (m, 5H), 1.55 – 1.40 (m, 5H), 1.39 – 0.99 (m, 46H), 0.96 – 0.84 (m, 12H). The following compound was prepared using analogous methodology as described above. N-(1-(2,2-di((Z)-Dec-4-en-1-yl)hydrazineyl)-1-oxododecan-3-y l)-N-(3-(dimethylamino)- propyl)decanamide (54). 1 H NMR (400 MHz, CDCl 3 ) δ 5.72 (d, J = 31.3 Hz, 1H), 5.45 – 5.22 (m, 4H), 4.45 (d, J = 57.4 Hz, 1H), 3.31 – 3.16 (m, 1H), 2.80 – 2.59 (m, 6H), 2.59 – 2.20 (m, 9H), 2.11 – 1.93 (m, 8H), 1.82 – 1.43 (m, 10H), 1.43 – 1.13 (m, 40H), 0.99 – 0.78 (m, 12H). Example 19. Synthesis of N-[3-(dimethylamino)propyl]-N-{1-[N'-(heptadecan-9- ylidene)hydrazinecarbonyl]undecan-2-yl}decanamide (55) Heptadecan-9-ylidenehydrazine (231 mg, 0.86 mmol), 3-{N-[3-(dimethylamino)- propyl]decanamido} dodecanoic acid (430mg, 0.95 mmol), EDC HCl (330 mg, 1.7 mmol) and DMAP (10 mg, 0.1 mmol) were stirred in DCM (20 mL) at RT for 16 hr. The reaction was quenched with sat. NaHCO 3 solution and extracted with DCM. The organics were washed with brine, dried (MgSO 4 ) concentrated in-vacuo and the residue purified by automated flash chromatography (5% MeOH/DCM) to give N-[3-(dimethylamino)propyl]-N-{1-[N'- (heptadecan-9-ylidene)hydrazinecarbonyl]undecan-2-yl}decanam ide (55) (176 mg, 29.0 %). 1 H NMR (400 MHz, CDCl 3 ) δ 8.19 (s, 1H), 4.53 – 4.38 (m, 1H), 3.73 – 3.65 (m, 1H), 3.39 – 3.09 (m, 3H), 2.95 – 2.86 (m, 1H), 2.82 – 2.65 (m, 3H), 2.59 – 2.19 (m, 12H), 2.19 – 2.10 (m, 2H), 1.57 – 1.41 (m, 6H), 1.40 – 1.15 (m, 46H), 0.95 – 0.84 (m, 12H). The following compounds were prepared using analogous methodology as described above. N-(3-(Dimethylamino)propyl)-N-(1-(2-((6Z,15Z)-henicosa-6,15- dien-11- ylidene)hydrazineyl)-1-oxododecan-3-yl)decanamide (56). (400 MHz, CDCl 3 ) δ 8.21 (s, 1H), 5.49 – 5.30 (m, 4H), 4.58 – 4.35 (m, 3H), 3.35 – 3.12 (m, 3H), 3.04 – 2.59 (m, 7H), 2.54 – 2.21 (m, 10H), 2.18 – 1.77 (m, 12H), 1.51 – 1.05 (m, 40H), 0.95 – 0.77 (m, 12H). N-(3-(dimethylamino)propyl)-N-(1-(2-((6Z,15Z)-henicosa-6,15- dien-11- ylidene)hydrazineyl)-1-oxododecan-3-yl)-2-hexyldecanamide (57). 1 H NMR (400 MHz, CDCl 3 ) δ 5.53 – 5.22 (m, 4H), 4.57 – 4.38 (m, 2H), 4.32 – 4.19 (m, 2H), 3.44 – 3.15 (m, 4H), 3.15 – 2.15 (m, 16H), 2.15 – 1.75 (m, 9H), 1.60 – 1.01 (m, 52H), 0.97 – 0.67 (m, 15H). Example 20. Synthesis of N-[3-(dimethylamino)propyl]-N-{1-[N'-(heptadecan-9- yl)hydrazinecarbonyl]undecan-2-yl}decanamide (58) Heptadecan-9-ylhydrazine (500 mg, 1.9 mmol.), 3-{N-[3-(dimethylamino)- propyl]decanamido}dodecanoic acid (925 mg, 2.0 mmol), EDC.HCl (709 mg, 3.7 mmol) and DMAP (23 mg, 0.19 mmol were stirred at RT for 16 hr. The reaction was quenched with sat. NaHCO 3 solution, extracted with DCM, washed with brine, dried (MgSO 4 ) and concentrated in-vacuo. The residue was purified by automated flash chromatography (0- 100% EtOAc/Hex and 0-10% MeOH/DCM) to give N-[3-(dimethylamino)propyl]-N-{1-[N'- (heptadecan-9-yl)hydrazinecarbonyl]undecan-2-yl}decanamide (58) (598 mg, 45.7 %). 1 H NMR (400 MHz, CDCl 3 ) δ 8.29 – 8.15 (m, 1H), 4.45 (s, 1H), 3.54 – 3.13 (m, 4H), 2.76 – 2.03 (m, 14H), 2.01 – 1.70 (m, 2H), 1.59 – 1.03 (m, 56H), 1.02 – 0.81 (m, 12H). The following compound was prepared using analogous methodology as described above. N-(3-(Dimethylamino)propyl)-N-(1-(2-((6Z,15Z)-henicosa-6,15- dien-11-yl)hydrazineyl)-1- oxododecan-3-yl)decanamide (59). 1 H NMR (400 MHz, CDCl 3 ) δ 8.20 (d, J = 25.7 Hz, 1H), 5.47 – 5.26 (m, 4H), 3.34 – 3.19 (m, 2H), 3.09 – 2.95 (m, 1H), 2.79 – 2.66 (m, 1H), 2.62 – 2.19 (m, 10H), 2.11 – 1.97 (m, 8H), 1.77 – 1.46 (m, 7H), 1.45 – 1.13 (m, 48H), 0.94 – 0.86 (m, 12H). Example 21. Synthesis of (3,5-dihexylphenyl)methyl 6-{N-[3-(dimethylamino)- propyl]decanamido}hexadecanoate (60) Step 1. Synthesis of (3,5-dihexylphenyl)methyl 6-oxohexadecanoate 6-Oxohexadecanoic acid (500 mg, 1.8 mmol), (3,5-dihexylphenyl)methanol) (511 mg, 1.8 mmol), DIPEA (1.0 mL, 5.5 mmol), EDC (710 mg, 3.7 mmol) and DMAP (100 mg, 0.19 mmol) were stirred in DCM (10 mL) at 0˚C for 16 hr allowing to warm to RT. The reaction was washed with sat NaHCO 3 and brine, dried (MgSO 4 ) filtered, concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% EtOAc/Hex) to give to (3,5- dihexylphenyl)methyl 6-oxohexadecanoate (546 mg, 55.8%). Step 2. Synthesis of (3,5-dihexylphenyl)methyl 6-{[3-(dimethylamino)propyl]- (3,5-Dihexylphenyl)methyl 6-oxohexadecanoate (546 mg, 1.1 mmol), dimethylaminopropane (119 mg, 1.2 mmol), AcOH (0.12 mL, 2.12 mmol) and NaCNBH3 (200 mg, 3.2 mmol) were stirred in a MeOH (10 mL) and DCM (3 mL) at RT for 15 hr. The reaction was concentrated in-vacuo and the residue partitioned between H 2 O (50 mL) and EtOAc (50 mL). The aqueous layer was extracted with EtOAc, the combined organics dried (Na2SO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-15% MEOH/DCM/0.5%TEA) to give (3,5-dihexylphenyl)methyl 6-{[3- (dimethylamino)propyl]amino}hexadecanoate (490 mg, 75.1 %). Step 3. (3,5-dihexylphenyl)methyl 6-{N-[3-(dimethylamino)propyl]- decanamido}hexadecanoate (60) (3,5-Dihexylphenyl)methyl 6-{[3-(dimethylamino)propyl]amino}hexadecanoate (163 mg, 0.27 mmol) and TEA (80 mg, 0.80 mmol) were dissolved in DCM (10 mL) followed by dropwise addition of decanoyl chloride (0.11 mL, 0.53 mmol) in DCM (10 mL). The reaction was stirred at RT for 20 hr, washed with sat. NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-15% MEOH/DCM) to give (3,5-dihexylphenyl)methyl 6-{N-[3- (dimethylamino)propyl]decanamido}hexadecanoate (60) (61 mg, 30.0 %). 1 H NMR (400 MHz, CDCl 3 ) δ 6.98 (s, 3H), 5.06 (s, 2H), 3.70 – 3.62 (m, 1H), 3.22 – 3.12 (m, 2H), 2.64 – 2.49 (m, 8H), 2.40 – 2.25 (m, 6H), 1.71 – 1.58 (m, 8H), 1.54 – 1.42 (m, 4H), 1.42 – 1.14 (m, 46H), 0.93 – 0.86 (m, 12H). The following compounds were prepared using analogous methodology as described above. 3,5-Dihexylbenzyl 6-(N-(3-(dimethylamino)propyl)tridecanamido)hexadecanoate (61). 1 H NMR (400 MHz, CDCl 3 ) δ 6.98 (s, 3H), 5.07 (s, 2H), 3.69 – 3.62 (m, 1H), 3.19 – 3.10 (m, 2H), 2.62 – 2.56 (m, 4H), 2.41 – 2.20 (m, 10H), 1.64 – 1.56 (m, 8H), 1.56 – 1.41 (m, 6H), 1.41 – 1.13 (m, 50H), 0.95 – 0.86 (m, 12H). 3,5-Dihexylbenzyl 6-(N-(3-(dimethylamino)propyl)-2-hexyldecanamido)hexadecanoa te (62). 1 H NMR (400 MHz, CDCl 3 ) δ 6.98 (s, 3H), 5.06 (s, 2H), 3.78 – 3.71 (m, 1H), 3.24 – 2.96 (m, 4H), 2.69 – 2.55 (m, 6H), 2.51 – 2.45 (m, 1H), 2.43 – 2.20 (m, 7H), 1.61 – 1.12 (m, 65H), 0.96 – 0.81 (m, 15H). Example 22. Synthesis of 2-Hexyldecyl 7-({9-[(2-hexyldecyl)oxy]-9- oxononyl}amino)heptadecanoate (63) Step 1. Synthesis of 2-Hexyldecyl 8-({8-[(2-hexyldecyl)oxy]-8-oxooctyl}amino)- octadecenoate 2-Hexyldecyl 8-oxooctadecanoate (743 mg, 1.4 mmol), 2-hexyldecyl 8-aminooctanoate (600 mg, 1.6 mmol) and AcOH (170 mg, 2.8 mmol) were stirred in MeOH at 50˚C for 30 mins. NaCNBH3 (268 mg, 4.3 mmol) was added and stirring continued for 16 hr. The solution was concentrated in-vacuo, taken up in EtOAc (75 mL), washed with sat'd NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% MeOH/DCM) to give 2-hexyldecyl 8-({8-[(2-hexyldecyl)oxy]-8- oxooctyl}amino)octadecanoate (567 mg, 44.8%). Step 2. Synthesis of 2-hexyldecyl 8-[4-(dimethylamino)-N-{8-[(2-hexyldecyl)oxy]-8- oxooctyl}butanamido]octadecenoate (63) 4-Dimethylaminobutanoic acid HCl salt (94 mg, 0.6 mmol), DMAP (103 mg, 0.84 mmol) and DCC (127 mg, 0.62 mmol) were stirred in ACN (1.25 mL) at RT for 2 hr.2- hexyldecyl 8-({8-[(2-hexyldecyl)oxy]-8-oxooctyl}amino)octadecanoate (250 mg, 0.28 mmol) in DCM (1.25 mL) was added and stirring continued for 18 hr. The reaction was concentrated in-vacuo, the residue suspended in hexanes and filtered and the filtrate concentrated in-vacuo. The residue was purified by automated flash chromatography (100% EtOAc then 0-10% MeOH/EtOAc) to give 2-hexyldecyl 8-[4-(dimethylamino)-N-{8-[(2- hexyldecyl)oxy]-8-oxooctyl}butanamido]octadecenoate (63) (64 mg, 22.7 %). 1 H NMR (400 MHz, CDCl 3 ) δ 3.99 (d, J = 5.9 Hz, 4H), 3.67 (s, 1H), 3.13 – 3.00 (m, 2H), 2.39 – 2.27 (m, 8H), 2.25 (s, 6H), 1.85 (q, J = 7.9 Hz, 3H), 1.63 (d, J = 10.2 Hz, 15H), 1.46 (s, 4H), 1.30 (s, 74H), 0.91 (d, J = 7.2 Hz, 15H). MS (ESI) m/z: [M + H]+ Calcd for C 64 H 126 N 2 O 5 1003.97; Found 1003.2 Note that HATU/DIPEA/DCM may also be used to produce the final amide coupling The following compounds were prepared using analogous methodology as described above. 2-Hexyldecyl 8-(5-(dimethylamino)-N-(8-((2-hexyldecyl)oxy)-8-oxooctyl)pen tanamido)- octadecenoate (64). 1 H NMR (400 MHz, CDCl 3 ) δ 3.99 (d, J = 6.0 Hz, 4H), 3.64 (s, 1H), 3.04 (d, J = 8.4 Hz, 2H), 2.41 – 2.26 (m, 8H), 2.24 (d, J = 3.1 Hz, 6H), 1.79 – 1.41 (m, 20H), 1.41 – 1.02 (m, 74H), 1.02 – 0.79 (m, 15H). MS (ESI) m/z: [M + H]+ Calcd for C 65 H 128 N 2 O 5 1017.98; Found 1017.2 3-Pentyloctyl 9-(5-(dimethylamino)-N-(9-oxo-9-((3-pentyloctyl)oxy)nonyl)-p entanamido)- nonadecanoate (65) . MS (ESI) m/z: [M + H]+ Calcd for C 59 H 116 N 2 O 5 933.89; Found 933. 3-Pentyloctyl 8-(N-(8-((3,5-dihexylbenzyl)oxy)-8-oxooctyl)-4-(dimethylamin o)- butanamido)-octadecenoate (66). 1 H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H), 6.99 (s, 2H), 5.07 (s, 2H), 4.09 (m, 2H), 3.05 (m, 2H), 2.83 (s, 6H), 2.65 (m, 10H), 2.29-2.37 (m, 5H), 1.28- 1.6 (m, 66H), 0.89 (m, 15H) 3-Pentyloctyl 8-(4-(dimethylamino)-N-(8-oxo-8-((3-pentyloctyl)oxy)octyl)-b utanamido)- octadecenoate (67). 1 H NMR (400 MHz, CDCl 3 ) δ 4.11 (d, J = 6.4 Hz, 4H), 3.66 (s, 1H), 3.11 – 3.01 (m, 2H), 2.33 (dq, J = 15.0, 6.8 Hz, 8H), 2.24 (s, 6H), 1.85 (h, J = 7.6 Hz, 2H), 1.61 (dq, J = 14.1, 7.2 Hz, 13H), 1.47 (s, 0H), 1.44 (s, 7H), 1.30 (d, J = 16.7 Hz, 60H), 0.91 (t, J = 6.9 Hz, 15H). MS (ESI) m/z: [M + H]+ Calcd for C 58 H 114 N 2 O 5 919.88; Found 920.0 Heptadecan-9-yl 8-(4-(dimethylamino)-N-(8-oxo-8-((3-pentyloctyl)oxy)-octyl)b utanamido)- octadecenoate (68) MS (ESI) m/z: [M + H]+ Calcd for C 62 H 122 N 2 O 5 975.94; Found 975.2 3-Hexylnonyl 8-(4-(dimethylamino)-N-(8-((3-hexylnonyl)oxy)-8-oxooctyl)-bu tanamido)- octadecenoate (69). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, 4H), 2.38 – 2.25 (m, 8H), 2.24 (s, 6H), 1.68 (s, 5H), 1.60 (dq, J = 15.2, 7.5 Hz, 13H), 1.49 – 1.40 (m, 5H), 1.33 (d, J = 7.5 Hz, 8H), 1.30 (s, 9H), 1.27 (s, 45H), 0.94 – 0.86 (m, 15H). 3-Pentyloctyl 8-(5-(dimethylamino)-N-(8-oxo-8-((3-pentyloctyl)oxy)octyl)-p entanamido)- octadecenoate (70). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, J = 7.1, 4H), 2.38 – 2.29 (m, 7H), 2.27 (s, 6H), 1.58 (dt, J = 17.0, 8.5 Hz, 19H), 1.43 (s, 7H), 1.29 (d, J = 15.8 Hz, 65H), 0.91 (t, J = 7.0 Hz, 15H). 3-Heptyldecyl 8-(4-(dimethylamino)-N-(8-((3-heptyldecyl)oxy)-8-oxooctyl)bu tanamido)- octadecenoate (71). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (td, J = 7.2, 2.6 Hz, 4H), 3.11 – 2.99 (m, 2H), 2.41 – 2.29 (m, 7H), 2.28 (s, 7H), 1.85 (dt, J = 14.9, 7.5 Hz, 2H), 1.75 (s, 8H), 1.60 (dt, J = 13.9, 6.8 Hz, 7H), 1.45 (t, J = 7.3 Hz, 6H), 1.37 – 1.18 (m, 76H), 0.94 – 0.87 (m, 15H). 2-Hexyldecyl 9-(5-(dimethylamino)-N-(9-((2-hexyldecyl)oxy)-9-oxononyl)pen tanamido)- nonadecanoate (72) MS (ESI) m/z: [M + H]+ Calcd for C 67 H 132 N 2 O 5 1045.01; Found 1046.3 3-Pentyloctyl 9-(5-(dimethylamino)-N-(8-oxo-8-((3-pentyloctyl)oxy)octyl)-p entanamido)- nonadecanoate (73). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t J = 7.1, 4H), 2.34 (s, 6H), 2.30 (t, J = 8.6 Hz, 5H), 1.62 – 1.56 (m, 17H), 1.49 – 1.41 (m, 6H), 1.30 (d, J = 16.9 Hz, 57H), 0.91 (t, J = 6.9 Hz, 15H). 2-Hexyldecyl 9-(5-(dimethylamino)-N-(8-((2-hexyldecyl)oxy)-8-oxooctyl)-pe ntanamido)- nonadecanoate (74). 1 H NMR (400 MHz, CDCl 3 ) δ 3.98 (d, J = 5.4 Hz, 4H), 2.38 – 2.29 (m, 7H), 2.27 (s, 6H), 1.84 – 1.77 (m, 3H), 1.64 (h, J = 7.0 Hz, 9H), 1.30 (d, J = 7.4 Hz, 78H), 0.90 (t, J = 6.6 Hz, 15H). 3-Pentyloctyl 8-(5-(dimethylamino)-N-(9-oxo-9-((3-pentyloctyl)oxy)nonyl)pe ntanamido)- octadecenoate (75). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, J = 7.3 Hz, 4H), 2.34 (dd, J = 14.1, 7.2 Hz, 5H), 2.29 (s, 6H), 1.62 (qq, J = 17.6, 5.4 Hz, 16H), 1.49 – 1.39 (m, 6H), 1.38 – 1.22 (m, 62H), 0.91 (t, J = 6.9 Hz, 15H). Example 23. Synthesis of 3-Hexylnonyl 9-[N-decyl-4-(dimethylamino)butanamido]-2- fluorooctadecanoate (76) Step 1. Synthesis of decyl[1-(oxan-2-yloxy)hexadecan-7-yl]amine 1-(Oxan-2-yloxy)hexadecan-7-one (5 g, 14.7 mmol) and N-decylamine (2.31 g, 14.7 mmol) were stirred in THF (100 mL) at 50˚C for 30 mins. NaBH(OAc)3 (9.3 g, 44.0 mmol) was added and stirring continued for 16 hr. The reaction was concentrated in-vacuo, the residue quenched with sat'd NaHCO 3 and the aqueous extracted with EtOAc. The organics were dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography to give decyl[1-(oxan-2-yloxy)hexadecan-7-yl]amine (4.9 g, 69.33%). Step 2. Synthesis of N-decyl-4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7- yl]butanamide 4-(Dimethylamino)butanoic acid HCl salt (4.0 g, 30.5 mmol), HATU (11.6 g, 30.5 mmol) and DIPEA (10.7 mL 61.0 mmol) were stirred in DCM (50 mL) at RT for 30 mins. Decyl[1-(oxan-2-yloxy)hexadecan-7-yl]amine (4.9 g, 10.2 mmol) in DCM was added and the reaction stirred until complete. The reaction was concentrated in-vacuo, the residue partitioned between satd NaHCO 3 and EtOAc. The organics were washed with brine, dried (MgSO 4 ) and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-15% MeOH/DCM) to give N-decyl-4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7- yl]butanamide (4.7 g, 77.7 %). Step 3. Synthesis of N-decyl-4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)butanam ide N-Decyl-4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl] butanamide (4.6 g, 7.7 mmol) and p-TsOH (67 mg, 0.4 mmol) were stirred in MeOH (150 mL) at RT for 16 hr. The methanol was removed in-vacuo, the residue taken up in EtOAc and washed with saturated NaHCO 3 . The organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give N-decyl- 4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)butanamide (3.5 g, 88.6 %) which was used without purification. Step 4. Synthesis of N-decyl-4-(dimethylamino)-N-(1-oxohexadecan-7-yl)butanamide N-Decyl-4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)butanam ide (3.5 g, 6.9 mmol) and PCC on Silica (1:1) (5.9 g, 13.7 mmol) were stirred in DCM (100 mL) at RT for 16 hr. The mixture was filtered through silica, concentrated in-vacuo and residue purified by automated flash chromatography (0-15% MeoH/DCM) to give N-decyl-4-(dimethylamino)-N- (1-oxohexadecan-7-yl)butanamide (1.8 g, 51.6 %). Step 5. Synthesis of ethyl (2Z)-9-[N-decyl-4-(dimethylamino)butanamido]-2-fluorooctadec - 2-enoate N-Decyl-4-(dimethylamino)-N-(1-oxohexadecan-7-yl)butanamide (1.8 g, 3.5 mmol), ethyl 2-(diethoxyphosphoryl)-2-fluoroacetate (1.7 g, 7.1 mmol) and DBU (1.1 g, 7.1 mmol) were stirred in THF (25 mL) at RT for 16 hr. The reaction was concentrated in-vacuo and the residue purified by automated flash chromatography (0-100% EtOAc/hexanes) to give ethyl (2Z)-9-[N-decyl-4-(dimethylamino)butanamido]-2-fluorooctadec -2-enoate (1.54 g, 72.9 %). Step 6. Synthesis of ethyl 9-[N-decyl-4-(dimethylamino)butanamido]-2- Ethyl (2Z)-9-[N-decyl-4-(dimethylamino)butanamido]-2-fluorooctadec -2-enoate (1.5 g, 2.5 mmol) was subjected to catalytic hydrogenation over Pd-C 10% (150 mg) in EtOAc at RT for 16 hr. The reaction was filtered through celite and concentrated in-vacuo to give ethyl 9-[N- decyl-4-(dimethylamino)butanamido]-2-fluorooctadecanoate (1.2 g, 79.7 %). Step 7. Synthesis of 9-[N-decyl-4-(dimethylamino)butanamido]-2-fluorooctadecanoic acid Ethyl 9-[N-decyl-4-(dimethylamino)butanamido]-2-fluorooctadecanoat e (1.2 g, 2.0 mmol) and LiOH (144 mg, 6.0 mmol) were stirred in THF (50 mL) at RT for 16 hr.6M HCl (1.3 mL) was added and the reaction extracted with DCM. The combined extracts were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 9-[N-decyl-4-(dimethylamino)butanamido]- 2-fluorooctadecanoic acid (810 mg, 70.8 %) which was used without purification. Step 8. Synthesis of 3-hexylnonyl 9-[N-decyl-4-(dimethylamino)butanamido]-2- fluorooctadecanoate (76) 9-[N-Decyl-4-(dimethylamino)butanamido]-2-fluorooctadecanoic acid (800 mg, 1.4 mmol), 2,4,6-trichlorobenzoyl chloride (684 mg, 2.8 mmol), 3-hexylnonan-1-ol (400 mg, 1.75 mmol) and DMAP (514 mg, 4.2 mmol were stirred in DCM (10 mL) at RT for 16 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc (50mL) and washed with 0.5 M NaOH (2 x 25 mL), water (25mL) and brine (25mL). The organics were dried (MgSO 4 ), concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% MeOH/DCM) to give 3-hexylnonyl 9-[N-decyl-4-(dimethylamino)butanamido]-2- fluorooctadecanoate (76) (468 mg, 42.7 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.92 (d, J = 5.8 Hz, 1H), 4.83 – 4.76 (m, 1H), 4.20 (t, J = 7.2 Hz, 2H), 3.62 (s, 1H), 3.04 (q, J = 7.2 Hz, 2H), 2.51 – 2.23 (m, 10H), 1.99 – 1.55 (m, 16H), 1.44 (q, J = 7.6 Hz, 10H), 1.26 (d, J = 8.5 Hz, 55H), 0.93 – 0.84 (m, 12H). 19 F NMR (376 MHz, CDCl 3 ) δ -191.86 (dtd, J = 49.6, 25.4, 19.6 Hz). MS (ESI) m/z: [M + H]+ Calcd for C49H97FN2O 3 781.8; Found 781.2 The following compound was prepared using analogous methodology as described above. 2-Hexyldecyl 9-(N-decyl-4-(dimethylamino)butanamido)-2-fluorooctadecanoat e (77). 1 H NMR (400 MHz, CDCl 3 ) δ 5.01 – 4.74 (m, 1H), 4.08 (d, J = 5.7 Hz, 2H), 3.63 – 3.50 (m, 1H), 3.25 (ddt, J = 11.1, 5.9, 2.2 Hz, 2H), 3.13 – 3.01 (m, 2H), 2.91 (d, J = 8.4 Hz, 6H), 2.79 – 2.72 (m, 1H), 2.68 (t, J = 5.6 Hz, 1H), 2.00 (d, J = 7.8 Hz, 3H), 1.95 – 1.80 (m, 2H), 1.60 – 1.39 (m, 1H), 1.37 – 1.08 (m, 58H), 0.88 (td, J = 6.9, 1.7 Hz, 12H). MS (ESI) m/z: [M + H]+ Calcd for C 5 0 H 99 FN 2 O 3 795.8; Found 795.6. The following compounds were prepared using analogous methodology as described above. Undecan-6-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2-fluorooctadecanoat e (112). 1 H NMR (400 MHz, CDCl 3 ) δ 5.13 – 4.90 (m, 2H), 4.82 (q, J = 5.4 Hz, 0H), 3.75 – 3.60 (m, 1H), 3.06 (q, J = 7.2 Hz, 2H), 2.35 (q, J = 6.9 Hz, 4H), 2.26 (s, 6H), 1.86 (dp, J = 14.5, 6.3 Hz, 4H), 1.75 – 1.09 (m, 64H), 0.90 (td, J = 6.8, 2.7 Hz, 12H). Tridecan-7-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2-fluorooctadecanoat e (113). 1 H NMR (400 MHz, CDCl 3 ) δ 5.12 – 4.92 (m, 2H), 4.82 (q, J = 5.4 Hz, 0H), 3.73 – 3.57 (m, 1H), 3.11 – 3.01 (m, 2H), 2.35 (q, J = 6.8 Hz, 4H), 2.27 (s, 6H), 1.87 (td, J = 12.5, 5.6 Hz, 4H), 1.77 – 1.39 (m, 17H), 1.30 (dq, J = 11.4, 6.4 Hz, 53H), 0.90 (t, J = 6.6 Hz, 12H). Pentadecan-8-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2-fluorooctadecanoat e (114). 1 H NMR (400 MHz, CDCl 3 ) δ 5.10 – 4.90 (m, 1H), 4.82 (q, J = 5.4 Hz, 0H), 3.74 – 3.57 (m, 1H), 3.06 (q, J = 7.3 Hz, 2H), 2.35 (q, J = 6.7 Hz, 4H), 2.26 (s, 6H), 1.87 (tt, J = 10.7, 6.0 Hz, 4H), 1.81 – 1.16 (m, 73H), 0.90 (t, J = 6.7 Hz, 12H). Heptadecan-9-yl 9-(N-decyl-4-(dimethylamino)butanamido)-2-fluorooctadecanoat e (115). 1 H NMR (400 MHz, CDCl 3 ) δ 5.08 – 4.90 (m, 1H), 4.82 (q, J = 5.5 Hz, 0H), 3.79 – 3.58 (m, 1H), 3.15 – 2.95 (m, 2H), 2.35 (q, J = 7.0 Hz, 4H), 2.25 (s, 6H), 1.86 (dp, J = 14.5, 6.4 Hz, 4H), 1.77 – 1.13 (m, 80H), 0.90 (t, J = 6.7 Hz, 12H). 2-Hexyldecyl 7-(N-decyl-4-(dimethylamino)butanamido)-2-fluorohexadecanoat e (120). 1 H NMR (400 MHz, CDCl 3 ) δ 4.97 (t, J = 5.8 Hz, 0H), 4.84 (q, J = 5.9 Hz, 0H), 4.11 (t, J = 4.9 Hz, 2H), 3.05 (d, J = 9.5 Hz, 2H), 2.57 – 2.24 (m, 10H), 2.20 (s, 1H), 1.95 – 1.80 (m, 4H), 1.67 (s, 6H), 1.48 (tt, J = 14.2, 8.8 Hz, 7H), 1.28 (dd, J = 10.0, 5.6 Hz, 53H), 0.95 – 0.86 (m, 12H). Tridecan-7-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2-fluorohexadecanoat e (121). 1 H NMR (400 MHz, CDCl 3 ) δ 5.05 – 4.85 (m, 2H), 4.79 (t, J = 6.0 Hz, 1H), 3.65 (s, 1H), 3.03 (t, J = 8.5 Hz, 2H), 2.32 (dt, J = 11.9, 6.9 Hz, 4H), 2.22 (s, 6H), 1.84 (dt, J = 15.0, 7.3 Hz, 4H), 1.73 – 1.35 (m, 16H), 1.27 (p, J = 6.9 Hz, 47H), 0.88 (t, J = 6.6 Hz, 12H). Pentadecan-8-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2-fluorohexadecanoat e (122). 1 H NMR (400 MHz, CDCl 3 ) δ 5.12 – 4.85 (m, 1H), 4.78 (d, J = 5.9 Hz, 1H), 3.64 (s, 1H), 3.02 (d, J = 9.0 Hz, 2H), 2.34 (p, J = 7.1 Hz, 4H), 2.26 (s, 6H), 1.85 (dd, J = 15.6, 8.3 Hz, 6H), 1.67 – 1.36 (m, 12H), 1.26 (q, J = 7.3 Hz, 51H), 0.88 (t, J = 6.6 Hz, 12H). Heptadecan-9-yl 7-(N-decyl-4-(dimethylamino)butanamido)-2-fluorohexadecanoat e (123). 1 H NMR (400 MHz, CDCl 3 ) δ 5.09 – 4.87 (m, 2H), 4.79 (t, J = 5.8 Hz, 1H), 3.04 (q, J = 9.7 Hz, 2H), 2.33 (q, J = 7.1 Hz, 4H), 2.24 (s, 5H), 1.84 (tt, J = 17.5, 8.4 Hz, 6H), 1.65 – 1.40 (m, 12H), 1.27 (d, J = 8.5 Hz, 57H), 0.88 (t, J = 6.6 Hz, 12H). Example 24. Synthesis of 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3-(dimethyl- amino)propyl]-8-oxooctanamido}octadecenoate (78) Step 1. Synthesis of 2-hexyldecyl 8-{[3-(dimethylamino)propyl]amino}octadecenoate 2-Hexyldecyl 8-oxooctadecanoate (500 mg, 1.0 mmol), dimethylaminopropylamine (117 mg, 1.14 mmol) and AcOH (0.11 mL, 1.9 mmol) were stirred in MeOH (15 mL) at 50˚C for 1 hr. The reaction was cooled to RT, NaCNBH 3 (180 mg, 2.9 mmol) added and stirring continued for 16 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc (50 mL) and washed with sat'd NaHCO 3 and brine. The organics were dried (MgSO 4 ), filtered, concentrated in-vacuo and the residue purified by automated flash chromatography (0-20% MeOH/DCM) to give 2-hexyldecyl8-{[3-(dimethylamino)propyl]amino} octadecanoate (430 mg, 73.8 %). Step 2. Synthesis of 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3-(dimethylamino)propyl]-8- oxooctanamido}octadecenoate (78) 8-[(2-Butyloctyl)oxy]-8-oxooctanoic acid (169 mg, 0.5 mmol), HATU (187 mg, 0.5 mmol) and DIPEA (0.12 mL, 0.66 mmol) were stirred in DCM (5 mL) at RT for 15 mins.2- Hexyldecyl 8-{[3-(dimethylamino)propyl]amino}octadecanoate (200 mg, 0.33 mmol) was added and stirring continued for 16 hr. The reaction was concentrated in-vacuo, The residue taken up in EtOAc (50 mL), washed with NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-5% MeOH/DCM, 100% EtOAc) to give 2-hexyldecyl 8-{8-[(2-butyloctyl)oxy]-N-[3- (dimethylamino)propyl]-8-oxooctanamido}octadecenoate (78) (112 mg, 36.5 %). 1 H NMR (400 MHz, CDCl 3 ) δ 3.96 (dd, J = 5.9, 3.0 Hz, 4H), 3.70 (s, 1H), 3.30 (bs, 2H), 3.13 (bs, 2H), 2.94 (s, 6H), 2.38 (t, J = 7.6 Hz, 2H), 2.30 (td, J = 7.4, 3.8 Hz, 4H), 1.96 (s, 2H), 1.62 (p, J = 6.6 Hz, 14H), 1.38 – 1.06 (m, 64H), 0.88 (t, J = 6.5 Hz, 15H). Note that the final amide coupling can be achieved using DCC/DMAP/DIPEA coupling methodology The following compounds were prepared using analogous methodology as described above. 2-Hexyldecyl 8-(8-(decyloxy)-N-(3-(dimethylamino)propyl)-8-oxooctanamido) - octadecenoate (79). 1 H NMR (400 MHz, CDCl 3 ) δ 4.08 (t, J = 6.8 Hz, 2H), 3.99 (d, J = 5.8 Hz, 2H), 3.74 (s, 1H), 3.33 (t, J = 6.0 Hz, 2H), 3.17 (s, 2H), 2.97 (s, 5H), 2.41 (t, J = 7.7 Hz, 2H), 2.33 (t, J = 7.5 Hz, 4H), 1.99 (s, 2H), 1.64 (t, J = 7.4 Hz, 12H), 1.29 (s, 57H), 0.91 (t, J = 6.7 Hz, 12H). 2-Hexyldecyl 8-(9-((2-butyloctyl)oxy)-N-(3-(dimethylamino)propyl)-9-oxono nanamido)- octadecenoate (80). 1 H NMR (400 MHz, CDCl 3 ) δ 3.98 (dd, J = 5.8, 2.3 Hz, 4H), 3.71 (s, 1H), 3.29 (t, J = 6.2 Hz, 2H), 3.04 (s, 2H), 2.86 (s, 6H), 2.82 (s, 20H), 2.38 (dd, J = 8.6, 6.2 Hz, 2H), 2.32 (t, J = 7.5 Hz, 4H), 1.94 (t, J = 6.5 Hz, 2H), 1.50 (dd, J = 29.4, 6.7 Hz, 13H), 1.38 – 1.24 (m, 68H), 0.94 – 0.88 (m, 15H). 2-Hexyldecyl 8-(10-((2-butyloctyl)oxy)-N-(3-(dimethylamino)propyl)-10-oxo decanamido)- octadecenoate (81). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, J = 7.1 Hz, 2H), 3.98 (d, J = 5.8 Hz, 2H), 3.29 (t, J = 6.5 Hz, 2H), 3.06 (d, J = 7.0 Hz, 2H), 2.87 (s, 6H), 2.83 (s, 1H), 2.38 (dd, J = 8.5, 6.5 Hz, 2H), 2.32 (td, J = 7.5, 2.5 Hz, 4H), 2.01 – 1.93 (m, 2H), 1.61 (dq, J = 20.5, 6.7 Hz, 10H), 1.41 – 1.17 (m, 68H), 0.91 (t, J = 6.7 Hz, 15H). 2-Hexyldecyl 8-(N-(3-(dimethylamino)propyl)-8-oxo-8-((2-pentyloctyl)oxy)- octanamido)- octadecenoate (82). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, J = 7.1 Hz, 2H), 3.98 (d, J = 5.8 Hz, 2H), 3.29 (t, J = 6.5 Hz, 2H), 3.06 (d, J = 7.0 Hz, 2H), 2.87 (s, 6H), 2.83 (s, 1H), 2.38 (dd, J = 8.5, 6.5 Hz, 2H), 2.32 (td, J = 7.5, 2.5 Hz, 4H), 2.01 – 1.93 (m, 2H), 1.61 (dq, J = 20.5, 6.7 Hz, 10H), 1.41 – 1.17 (m, 68H), 0.91 (t, J = 6.7 Hz, 15H). 2-Hexyldecyl 8-(8-((3,5-dihexylbenzyl)oxy)-N-(3-(dimethylamino)propyl)-8- oxooctanamido)-octadecenoate (83). 1 H NMR (400 MHz, CDCl 3 ) δ 6.98 (m, 3H), 5.07 (s, 2H), 3.98 (dd, J = 5.9, 2.8 Hz, 2H), 3.69 – 3.56 (m, 1H), 3.12 (t, J = 8.0 Hz, 2H), 2.59 (t, J = 7.8 Hz, 4H), 2.42 – 2.20 (m, 13H), 1.79 – 1.56 (m, 21H), 1.46 (t, J = 7.2 Hz, 4H), 1.41 – 1.10 (m, 61H), 0.98 – 0.86 (m, 15H). 2-Hexyldecyl 8-(N-(3-(dimethylamino)propyl)-8-((3-hexylnonyl)oxy)-8-oxooc tanamido)- octadecenoate (84). 1 H NMR (400 MHz, CDCl 3 ) δ 4.10 (t, J = 7.1 Hz, 2H), 3.98 (dd, J = 5.8, 1.9 Hz, 2H), 3.20 (t, J = 7.5 Hz, 2H), 2.75 (s, 2H), 2.58 (s, 6H), 2.31 (qd, J = 7.5, 2.9 Hz, 6H), 2.26 (s, 2H), 1.88 (t, J = 7.4 Hz, 2H), 1.74 – 1.55 (m, 10H), 1.49 (td, J = 13.1, 5.6 Hz, 4H), 1.41 – 1.19 (m, 69H), 0.90 (t, J = 6.7 Hz, 15H). 2-Hexyldecyl 8-(N-(3-(dimethylamino)propyl)-8-((3-heptyldecyl)oxy)-8-oxoo ctanamido)- octadecenoate (85). 1 H NMR (400 MHz, CDCl 3 ) δ 4.09 (t, J = 7.1 Hz, 2H), 3.98 (dd, J = 5.8, 3.2 Hz, 2H), 3.13 (dd, J = 10.4, 5.9 Hz, 2H), 2.30 (pd, J = 4.9, 3.0 Hz, 8H), 2.24 (s, 6H), 1.77 – 1.55 (m, 13H), 1.47 (q, J = 7.5 Hz, 4H), 1.29 (dd, J = 8.3, 5.0 Hz, 74H), 0.94 – 0.86 (m, 15H). Example 25. Synthesis of 3-pentyloctyl 8-[4-(dimethylamino)-N-{6-fluoro-7-oxo-7-[(3- pentyloctyl)oxy]heptyl}butanamido]octadecenoate (86) 5-(Oxan-2-yloxy)pentan-1-amine (1.8 g, 9.6 mmol) and methyl 8-oxooctadecanoate (3 g, 9.6 mmol) were heated in THF (25 mL) at 50˚C for 45 mins. NaBH(OAc)3 (6.1g, 28.8 mmol) was added and stirring continued for 16 hr. After cooling to RT the reaction was concentrated in-vacuo, the residue taken up in EtOAc (100 mL), washed with NaHCO 3 and brine, dried (MgSO 4 ) and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-100% EtOAc/Hex) to give methyl 8-{[5-(oxan-2- yloxy)pentyl]amino}octadecanoate (1.6 g, 34.5 %). Step 2. Synthesis of methyl 8-[4-(dimethylamino)-N-[5-(oxan-2-yloxy)pentyl]- butanamido]octadecenoate 4-(Dimethylamino)butanoic acid HCl (1.30 g, 9.9 mmol), DIPEA (3.5 mL, 20.0 mmol) and HATU (3.8 g, 9.9 mmol) were stirred in DCM (50 mL) at RT for 30 mins. Methyl 8-{[5- (oxan-2-yloxy)pentyl]amino}octadecanoate (1.6 g, 3.3 mmol) in DCM (10 mL) was added and stirring continued for 16 hr at RT. The reaction was concentrated in-vacuo and the residue taken up in EtOAc. The combined organics were washed with 0.5 M NaOH, water and brine (25 mL), dried (MgSO 4 ) and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-15% MeOH/DCM) to give methyl 8-[4-(dimethylamino)-N-[5-(oxan-2- yloxy)pentyl]butanamido]octadecanoate (1.85 g, 93.7 %). Step 3. Synthesis of methyl 8-[4-(dimethylamino)-N-(5-hydroxypentyl)butanamido]- octadecenoate Methyl 8-[4-(dimethylamino)-N-[5-(oxan-2-yloxy)pentyl]butanamido]oc tadecanoate (1.9 g, 3.2 mmol) and p-ToSH.H 2 O (27 mg 0.16 mmol) were stirred in MeOH (25 mL) at RT for 16 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc (100mL) washed with sat'd NaHCO 3 , dried (MgSO 4 ), filtered and concentrated in-vacuo to give methyl 8-[4- (dimethylamino)-N-(5-hydroxypentyl)butanamido]octadecanoate (Quant) which was used without purification. Step 4. Synthesis of methyl 8-[4-(dimethylamino)-N-(5-oxopentyl)butanamido]- octadecenoate Methyl 8-[4-(dimethylamino)-N-(5-hydroxypentyl)butanamido]octadecan oate (1.6 g, 3.1 mmol) and PCC/Silica 1:1 wt (1.3 g, 3.12 mmol) were stirred in DCM (50 mL) at RT for 16 hr. The reaction was filtered through silica gel eluting with DCM. The filtrate was concentrated in-vacuo and the residue purified by automated flash chromatography (0-20% MeOH/DCM) to give methyl 8-[4-(dimethylamino)-N-(5-oxopentyl)butanamido]octadecanoate (1.6 g, Quant). Methyl 8-[4-(dimethylamino)-N-(5-oxopentyl)butanamido]octadecanoate (1.6 g, 3.1 mmol), ethyl 2-(diethoxyphosphoryl)-2-fluoroacetate (1.9 g, 7.8 mmol) and DBU (1.17 mL, 7.8) were stirred in anhydrous THF (25 mL) at RT for 16 hr. Additional ethyl 2- (diethoxyphosphoryl)-2-fluoroacetate (379 mg, 1.6 mmol) and DBU (0.23 mL, 1.6 mmol) were added and stirring continued for another 3 hr. The reaction was concentrated in-vacuo and the residue purified by automated flash chromatography (0-15% MeOH/DCM, 0-100% EtOAc/Hex) to give methyl 8-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7-oxohept-5-en-1- yl)butanamido]octadecenoate (500 mg, 26.7 %). Step 6. Synthesis of methyl 8-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7- oxoheptyl)butanamido]octadecenoate Methyl 8-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7-oxohept-5-en-1- yl)butanamido]octadecanoate (500 mg, 0.84 mmol) was subjected to catalytic hydrogenation over Palladium on Carbon (50 mg) in EtOH (25 mL) at RT for 16 hr. The reaction was filtered through celite and the filtrate concentrated in-vacuo to give methyl 8-[4-(dimethylamino)-N-(7- ethoxy-6-fluoro-7-oxoheptyl)butanamido]octadecanoate (375 mg, 74.7 %) which was used without purification. Step 7. Synthesis of 8-[N-(6-carboxy-6-fluorohexyl)-4-(dimethylamino)butanamido]- octadecanoic acid Methyl 8-[4-(dimethylamino)-N-(7-ethoxy-6-fluoro-7- oxoheptyl)butanamido]octadecanoate (375 mg, 0.6 mmol) and LiOH (60.0 mg, 2.5 mmol) were stirred in THF (10 mL) at RT for 16 hr.6M HCl (0.6 mL) was added, the reaction diluted with H 2 O and the reaction extracted with DCM. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 8-[N-(6-carboxy-6-fluorohexyl)-4- (dimethylamino)butanamido]octadecanoic acid (205 mg, 59.0 %) which was used without purification. Step 8. Synthesis of 3-pentyloctyl 8-[4-(dimethylamino)-N-{6-fluoro-7-oxo-7-[(3- pentyloctyl)oxy]heptyl}butanamido]octadecenoate (86) 8-[N-(6-Carboxy-6-fluorohexyl)-4-(dimethylamino)butanamido]o ctadecanoic acid (200 mg, 0.36 mmol), 3-pentyloctan-1-ol (215 mg, 1.0 mmol), DMAP (175 mg, 1.4 mmol) and 2,4,6-trichlorobenzoyl chloride (262 mg, 1.0 mmol) were stirred in DCM (10 mL) at RT for 16 hr. The reaction was concentrated in-vacuo the residue taken up in EtOAc and washed with 0.5 M NaOH, H 2 O and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-25% ACN/DCM, 0-15% MeOH/DCM) to give 3-pentyloctyl 8-[4-(dimethylamino)-N-{6-fluoro-7-oxo-7-[(3- pentyloctyl)oxy]heptyl}butanamido]octadecenoate (86) (93 mg, 28.14 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.97 (ddd, J = 6.9, 4.5, 2.3 Hz, 1H), 4.85 (ddd, J = 7.1, 5.1, 2.4 Hz, 1H), 4.23 (tt, J = 7.3, 2.0 Hz, 2H), 4.09 (t, J = 7.1 Hz, 2H), 3.59 (s, 1H), 3.33 – 3.23 (m, 2H), 3.10 (d, J = 9.1 Hz, 2H), 2.95 (d, J = 11.7 Hz, 6H), 2.82 – 2.76 (m, 1H), 2.72 (t, J = 5.6 Hz, 1H), 2.30 (td, J = 7.5, 3.1 Hz, 2H), 2.06 – 1.84 (m, 4H), 1.71 – 1.38 (m, 22H), 1.38 – 1.16 (m, 55H), 0.91 (tt, J = 7.1, 1.5 Hz, 15H). MS (ESI) m/z: [M + H]+ Calcd for C 57 H 111 FN 2 O 5 923.9; Found 923.2 Example 26. Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3- pentyloctyl)oxy]octyl}butanamido]-2,2-difluorononadecanoate (87) Step 1. Synthesis of 3-pentyloctyl 8-(heptadec-1-en-7-ylamino)octanoate 3-Pentyloctyl 8-aminooctanoate (1.2 g, 3.5 mmol), heptadec-1-en-7-one (872 mg, 3.5 mmol) and AcOH acid (200 µL, 3.5 mmol) were stirred in MeOH at 60˚C for 30 mins. NaCNBH3 was added and stirring continued for 16 hr. The reaction was concentrated in-vacuo, the residue taken-up in DCM, washed with NaHCO 3 (sat. aq.) and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-60% EtOAc/Hex) to give 3-pentyloctyl 8-(heptadec-1-en-7-ylamino)octanoate (1.33 g, 66.7 %). Step 2. Synthesis of 3-pentyloctyl 8-[4-(dimethylamino)-N-(heptadec-1-en-7- yl)butanamido]octanoate 4-(Dimethylamino)butyric acid hydrochloride (1.16 g, 6.9 mmol), HATU (3.15 g, 8.3 mmol) and DIPEA (3.6 mL, 20.7 mmol) were stirred in DCM (40 mL) at RT for 3 hr.3- Pentyloctyl 8-(heptadec-1-en-7-ylamino)octanoate (1.33 g, 2.3 mmol) in DCM (40 mL) was added and stirring continued for 18 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc, washed with sat'd NaHCO 3 and the aqueous layer back extracted with EtOAc. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-100% EtOAc/Hex and 0- 20% MeOH/EtOAc) to give 3-pentyloctyl 8-[4-(dimethylamino)-N-(heptadec-1-en-7- yl)butanamido]octanoate (1.54 g, 97.1 %). Step 3. Synthesis of ethyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]- octyl}butanamido]-2,2-difluorononadecanoate In a heat/vacuum dried flask, Hantsch ester (566 mg, 2.24 mmol), NaOAc (367 mg, 4.5 mmol), AgOTf (1.44 g, 5.6 mmol) and iodobenzene diacetate (1.44 g, 4.471 mmol, 2 equiv.) were stirred in NMP (15mL) under N2.3-Pentyloctyl 8-[4-(dimethylamino)-N- (heptadec-1-en-7-yl)butanamido]octanoate (1.55 g, 2.24 mmol) in NMP (7 mL) and ethyl 2,2- difluoro-2-(trimethylsilyl)acetate (2.2 g, 11.2 mmol) were added and the reaction stirred at RT for 18 hr. The reaction was filtered through Celite eluting with Et 2 O. The combined organics were washed with brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-25% ACN/DCM) to give ethyl 9-[4- (dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}butanam ido]-2,2- difluorononadecanoate (588 mg, 32.3 %. Step 4. Synthesis of 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}- butanamido]-2,2-difluorononadecanoic acid Ethyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}bu tanamido]-2,2- difluorononadecanoate (588 mg, 0.7 mmol) and LiOH 1M (2.2 mL, 2.2 mmol) were stirred in THF (10 mL) at 0˚C until the reaction was completed.6M HCl (0.36 mL) was added the reaction azeotroped with toluene. The residue was taken up in DCM, dried (MgSO 4 ), filtered and concentrated in-vacuo to give 9-[4-(dimethylamino)-N-{8-oxo-8-[(3- pentyloctyl)oxy]octyl}butanamido]-2,2-difluorononadecanoic acid (600 mg, 98.8 %) which was used without purification. Step 5. Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]- octyl}butanamido]-2,2-difluorononadecanoate (87) 9-[4-(Dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}bu tanamido]-2,2- difluorononadecanoic acid (561 mg, 0.7 mmol), 3-pentyloctan-1-ol (157 mg, 0.78 mmol), 2,4,6- trichlorobenzoyl chloride (382 mg, 1.6 mmol) and DMAP (261 mg, 2.1 mmol) were combined in DCM (10 mL) at 0˚C. The reaction was stirred for 16 hr allowing to warm to RT. Et 2 O was added and the resultant PPT removed by filtration. The organics were washed with NaHCO 3 , dried (MgSO 4 ), filtered, concentrated in-vacuo and the residue purified by automated flash chromatography (0-10 % MeOH/DCM and 1:1 ACN/DCM 3CV, 0-20 % MeOH/DCM) to give 3-pentyloctyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}bu tanamido]- 2,2-difluorononadecanoate (87) (128 mg, 18.5 %). 1 H NMR (400 MHz, MeOD) δ 4.33 (t, J = 6.7 Hz, 2H), 4.12 (t, J = 6.8 Hz, 2H), 3.19 (d, J = 8.3 Hz, 1H), 3.12 (d, J = 9.0 Hz, 2H), 2.81 (t, J = 7.5 Hz, 3H), 2.62 (s, 6H), 2.52 (dt, J = 10.2, 7.0 Hz, 3H), 2.33 (td, J = 7.3, 4.3 Hz, 3H), 1.93 (h, J = 7.1 Hz, 3H), 1.64 (dq, J = 29.9, 6.6 Hz, 9H), 1.55 (s, 3H), 1.46 (s, 3H), 1.39 (d, J = 3.8 Hz, 7H), 1.37 (s, 9H), 1.31 (d, J = 4.2 Hz, 39H), 0.93 (t, J = 6.9 Hz, 15H). Example 27. Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3- pentyloctyl)oxy]octyl}butanamido]-2-fluorooctadecanoate (88) Step 1. Synthesis of methyl 8-{[1-(oxan-2-yloxy)hexadecan-7-yl]amino}octanoate 1-(Oxan-2-yloxy)hexadecan-7-one (5.7 g, 16.7 mmol), methyl 8-aminooctanoate (2.9 g, 16.7 mmol) and NaCN(OAc) 3 (10.6 g, 50.2 mmol) were stirred in THF at 50˚C for 16 hr. The reaction was filtered, eluting with EtOAc and the organics washed with NaHCO 3 satd soln, water and brine. The organics were dried (MgSO 4 ) concentrated in-vacuo and purified by automated flash chromatography (7%MeOH/DCM) to give methyl 8-{[1-(oxan-2- yloxy)hexadecan-7-yl]amino}octanoate (2.9 g, 34.2 %). 4-Dimethylaminobutanoic acid HCl salt (3.84 g, 22.9 mmol), HATU (8.7 g, 22.9 mmol) and DIPEA ( 8.0 mL, 45.8 mmol) were stirred in DCM (40 mL) for 3 hr at RT. Methyl 8-{[1-(oxan-2-yloxy)hexadecan-7-yl]amino}octanoate (2.85 g, 5.7 mmol) in DCM (40 mL) was added and stirring continued for 18 hr. The reaction was concentrated in-vacuo, the residue taken up in EtOAc, washed with sat'd NaHCO 3 and the aqueous layer extracted with additional EtOAc. The combined organics were concentrated in-vacuo and the crude material purified by automated flash chromatography (0-100% EtOAc/Hex, and 0-20% MeOH/EtOAc) to give methyl 8-[4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl]butan amido]octanoate (Quant). Step 3. Synthesis of methyl 8-[4-(dimethylamino)-N-(1-hydroxyhexadecan-7- Methyl 8-[4-(dimethylamino)-N-[1-(oxan-2-yloxy)hexadecan-7-yl]butan amido]- octanoate (3.5 g, 5.7 mmol) and pTsOH-H 2 O (109 mg, 0.57 mmol) were stirred in MeOH at RT for 2.5 hr. The reaction was concentrated in-vacuo to give methyl 8-[4-(dimethylamino)-N-(1- hydroxyhexadecan-7-yl)butanamido]octanoate (5.06 g)which was used without purification. Step 4. Synthesis of methyl 8-[4-(dimethylamino)-N-(1-oxohexadecan-7- yl)butanamido]octanoate Methyl 8-[4-(dimethylamino)-N-(1-hydroxyhexadecan-7-yl)butanamido]o ctanoate (3.02 g, 5.73 mmol) and PCC-SiO2 (1:1) (4.3 g, 10.0 mmol) were stirred in DCM at RT for 16 hr. MeCN was added and the reaction filtered through silica eluting with 1:1 MeCN/DCM. The filtrate was concentrated in-vacuo the residue taken up in EtOAc and filtered through celite. The filtrate was concentrated in-vacuo and purified by automated flash chromatography (0-50% ACN/DCM) to give methyl 8-[4-(dimethylamino)-N-(1-oxohexadecan-7- yl)butanamido]octanoate (1.79 g, 59.3 %) Step 5. Synthesis of ethyl (2Z)-9-[4-(dimethylamino)-N-(8-methoxy-8- oxooctyl)butanamido]-2-fluorooctadec-2-enoate Methyl 8-[4-(dimethylamino)-N-(1-oxohexadecan-7-yl)butanamido]octan oate (1.79 g, 3.4 mmol), ethyl 2-(diethoxyphosphoryl)-2-fluoroacetate (1.4 g, 6.0 mmol) and DBU (0.9 mL, 6.0 mmol) were stirred in THF at RT for 16 hr. The reaction was concentrated in-vacuo and the residue taken up in EtOAc. The organics were washed with NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The crude material was purified by automated flash chromatography (0-100% EtOAc/Hex and 0-15% MeOH/DCM) to give Synthesis of ethyl (2Z)- 9-[4-(dimethylamino)-N-(8-methoxy-8-oxooctyl)butanamido]-2-f luorooctadec-2-enoate (626 mg, 30.0 %) Step 6. Synthesis of ethyl 9-[4-(dimethylamino)-N-(8-methoxy-8-oxooctyl)butanamido]-2- fluorooctadecanoate Ethyl (2Z)-9-[4-(dimethylamino)-N-(8-methoxy-8-oxooctyl)butanamido ]-2- fluorooctadec-2-enoate (620 mg, 1.0 mmol) was subjected to catalytic hydrogenation over Pd- C in EtOH at RT for 16 hr. The reaction was filtered through celite and concentrated in-vacuo to give ethyl 9-[4-(dimethylamino)-N-(8-methoxy-8-oxooctyl)butanamido]-2-f luorooctadecanoate (550 mg, 88.4 %) which was used without purification. Step 7. Synthesis of 9-[N-(7-carboxyheptyl)-4-(dimethylamino)butanamido]-2- fluorooctadecanoic acid Ethyl 9-[4-(dimethylamino)-N-(8-methoxy-8-oxooctyl)butanamido]-2- fluorooctadecanoate (550 mg, 0.90 mmol) and LiOH (96 mg, 4.0 mmol) were stirred in THF at RT for 16 hr. The reaction was concentrated in-vacuo, acidified with 6 M HCl (1.0 mL) and extracted into DCM (50 mL). The organics were washed with brine and the aqueous layer further extracted with DCM. The combined organics were dried (MgSO 4 ), filtered and concentrated in-vacuo to give 9-[N-(7-carboxyheptyl)-4-(dimethylamino)butanamido]-2- fluorooctadecanoic acid (284 mg, 55.4 %) which was used without further purification. Step 8. Synthesis of 3-pentyloctyl 9-[4-(dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]- octyl}butanamido]-2-fluorooctadecanoate (88) 9-[N-(7-Carboxyheptyl)-4-(dimethylamino)butanamido]-2-fluoro octadecanoic acid (275 mg, 0.48 mmol), 3-pentyloctan-1-ol (289 mg, 1.44 mmol), 2,4,6-trichlorobenzoyl chloride (351 mg, 1.44 mmol) and DMAP (235 mg, 1.92 mmol) were combined at 0˚C in DCM (10 mL). The reaction was stirred for 16 hr allowing to warm to RT. The reaction was concentrated in- vacuo and the residue taken up in EtOAc. The combined organics were washed with sat'd NaHCO 3 and brine, dried (MgSO 4 ), filtered and concentrated in-vacuo. The residue was purified by automated flash chromatography (0-10% MeOH/DCM) to give 3-pentyloctyl 9-[4- (dimethylamino)-N-{8-oxo-8-[(3-pentyloctyl)oxy]octyl}butanam ido]-2-fluorooctadecanoate (88) (211 mg, 46.9 %). 1 H NMR (400 MHz, CDCl 3 ) δ 4.23 (td, J = 7.1, 2.1 Hz, 2H), 4.10 (td, J = 7.1, 4.0 Hz, 2H), 3.09 – 3.01 (m, 2H), 2.33 (dt, J = 23.1, 7.3 Hz, 9H), 1.69 – 1.53 (m, 11H), 1.38 – 1.18 (m, 57H), 0.95 – 0.86 (m, 15H). 19 F NMR (376 MHz, CDCl 3 ) δ -191.67 – -192.07 (m). Example 28. Synthesis of 3-hexylnonyl 8-(decyl((3-(dimethylamino)propoxy)carbonyl)- amino) octadecanoate (105) Step 1: Synthesis of 3-(dimethylamino)propyl (4-nitrophenyl) carbonate hydrochloride 3-(Dimethylamino)propan-1-ol (2.5 g, 24.2 mmol) in DCM (20 mL) was added dropwise to a stirred solution of 4-nitrophenyl chloroformate (4.9 g, 24.2 mmol) in DCM (80 mL) at 0°C. The reaction was stirred for 16 h allowing to warm to RT. The solvent was removed in-vacuo to give 3-(dimethylamino)propyl (4-nitrophenyl) carbonate hydrochloride (5.3 g, 70.9%) as a crude mixture which was used without further purification. Step 2: Synthesis of 3-hexylnonyl 8-(N-decyl-5-(dimethylamino)pentanamido)octadecenoate (105) 3-Hexylnonyl 8-(decylamino)octadecanoate (0.61 g, 0.94 mmol), triethylamine (0.29 g, 2.82 mmol) and 3-(dimethylammonio)propyl 4-nitrophenyl carbonate hydrochloride (0.36 g, 1.18 mmol) were stirred in DCM at RT for 16 h. An additional 1 eq of 3-(dimethylammino)propyl 4- nitrophenyl carbonate hydrochloride and triethylamine were added wit DMAP (cat) and the reaction heated at reflux for 16 h. The solvent was removed in-vacuo and the residue taken up in hexanes, filtered, and concentrated. The resulting oil was taken up in DCM and decanoyl chloride (90 mg, 0.5 equiv.) added and stirred for 15 minutes. The reaction was concentrated in-vacuo, diluted with diethyl ether, washed with NaHCO 3 saturated solution and brine, dried (MgSO 4 ), filtered, and concentrated. The residue was purified with automated flash chromatography (0-10% MeOH/DCM) to give 3-hexylnonyl 8-[decyl({[3-(dimethylamino)propoxy]carbonyl})amino] octadecanoate (0.30 g, 40.5%). 1 H NMR (400 MHz, CDCl 3 ) δ 4.09 (dt, J = 17.8, 6.7 Hz, 4H), 3.02 – 2.89 (m, 2H), 2.39 (d, J = 7.6 Hz, 2H), 2.26 (d, J = 4.5 Hz, 7H), 1.82 (s, 6H), 1.57 (dp, J = 16.8, 8.4 Hz, 4H), 1.41 (d, J = 10.5 Hz, 3H), 1.35 – 1.23 (m, 55H), 0.88 (td, J = 6.8, 1.9 Hz, 12H). General Methods Lipid nanoparticle formulations The lipid solution contains 4 components: a PEG-conjugated lipid, an ionizable lipid, cholesterol, and a phospholipid (e.g., DSPC). Lipid stocks were prepared using the lipid identities and molar ratios as described, to achieve a total concentration of ~7 mg/mL in 100% ethanol. Firefly luciferase mRNA (TriLink Biotechnologies, L-7202) or ornithine transcarbamylase (OTC) mRNA (TriLink Biotechnologies, custom designed) was diluted in acetate, pH 5 buffer and nuclease free water to achieve a target concentration of 0.366 mg/mL mRNA in 100 mM acetate, pH 5. Equal volumes of the lipid and nucleic acid solutions were blended at a flow rate of 400 mL/min through a T-connector, and diluted with ~4 volumes of PBS, pH 7.4. Formulations were placed in Slide-A-Lyzer dialysis units (MWCO 10,000) and dialyzed overnight against 10 mM Tris, 500 mM NaCl, pH 8 buffer. Following dialysis, the formulations were concentrated to ~ 0.6 mg/mL using VivaSpin concentrator units (MWCO 100,000) and dialyzed overnight against 5 mM Tris, 10% sucrose, pH 8 buffer. Formulations were filtered through a 0.2 µm syringe filter (PES membrane). Nucleic acid concentration was determined by the RiboGreen assay. Particle size and polydispersity were determined using a Malvern Nano Series Zetasizer. In vivo administration of luciferase LNPs LNP formulations encapsulating firefly luciferase mRNA were injected intravenously at 0.5 mg/kg to female BALB/c mice (6-8 weeks old). On day of injection, the LNP stocks were filtered and diluted to the required dosing concentration with phosphate buffered saline. At 6 hours post-administration, animals were anaesthetized with a lethal dosage of ketamine/xylazine. Liver samples (left lateral lobe) were collected, weighed, and flash frozen in liquid nitrogen. Liver samples were stored in FastPrep® tubes at -80 o C until analyzed for luciferase activity. Luciferase activity analysis Frozen aliquots of liver were thawed and homogenized in 1mL of 1xCCLR (Cell Culture Lysis Reagent) using a FastPrep® homogenizer. The homogenate was then centrifuged at 16,000 RPM for 10 minutes at 4 o C. Twenty (20) µL of the supernatant was loaded into a 96-well white plate and luminescence measured following addition of luciferase reagent (Promega Luciferase Assay System). Luciferase activity was determined by comparing luminescence of the homogenized samples to luciferase protein standards. To account for any quenching of luminescence by components in the liver homogenate, luciferase was added to the liver homogenates of untreated animals and the resulting luminescence measured. The resulting quench factor was applied to all samples to obtain the corrected luciferase activity, and normalized per unit mass of tissue analyzed. In vivo administration of OTC LNPs LNP formulations encapsulating ornithine transcarbamylase mRNA were injected intravenously at the specified dose levels to male C57BL/6 mice (6-8 weeks old). On day of injection, the LNP stocks were filtered and diluted to the required dosing concentration with phosphate buffered saline. At 24 hours post-administration, animals were anaesthetized with a lethal dosage of ketamine/xylazine. Liver samples (left lateral lobe) were collected, weighed, and flash frozen in liquid nitrogen. Liver samples were stored in FastPrep® tubes at -80 o C until analyzed for OTC expression. Human OTC expression analysis Liver homogenates were prepared with PBS, Halt protease inhibitor cocktail and FastPrep homogenization, standardized to 2 mg/mL protein with a BCA Protein Assay, and then analyzed by ELISA. Briefly, samples were diluted with PBS and plated on Nunc Maxisorp plates. A standard curve using human PROTEIN 1 protein was prepared from the naïve animal controls (vehicle). After 2 h incubation the plates were washed, and the primary antibody was added. After 1 h incubation, the secondary antibody was added and incubated for another hour. After washing, TMB Substrate was added for color development and the reaction was stopped with 2 N sulfuric acid. The plate was read at 450/570 OD. In vivo administration of EGFP LNPs LNP formulations encapsulating enhanced green fluorescent protein mRNA were injected intravenously at 0.5 mg/kg to female BALB/c mice (6-8 weeks old). On day of injection, the LNP stocks were filtered and diluted to the required dosing concentration with phosphate buffered saline. At 24 hours post-administration, animals were anaesthetized with a lethal dosage of ketamine/xylazine. Liver samples (left lateral lobe) were collected, weighed, and flash frozen in liquid nitrogen. Liver samples were stored in FastPrep ® tubes at -80 o C until analyzed for EGFP expression. EGFP expression analysis Liver homogenates were prepared in cell extraction buffer, diluted, and analyzed for EGFP protein levels using ELISA, according to manufacturer’s instructions (Abcam, GFP ELISA Kit). Lipid LC-MS analysis Liver tissues were treated with PBS and homogenized with a FastPrep machine, 3 cycles of 5 m/s x 15 s. Homogenates from the PBS-treated control animals was pooled and used for standard curve preparation. Samples were extracted into a deep well plate with 250 uL of an internal suitability standard. Plates were centrifuged for 15 min at 4 o C and 2000 rpm. Analysis was performed using an Agilent 6520 QTOF coupled to an Agilent 1290 UHPLC, using reverse- phase LC separation. Quantitation of the ionizable lipid was by MS/MS against a calibration curve spiked into appropriately matched blank matrix. Calibration used a similar class of synthetic lipid as internal standard. Example 29. Particle characteristics of LNP formulations containing novel ionizable lipids LNP formulations containing novel ionizable lipids all produced stable particles with high encapsulation efficiency (Tables 1-7). The following compound, identified as 13-B43 is included for comparison below: Table 1. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 2. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 3. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 4. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 5. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 6. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Table 7. Particle characteristics of LNPs containing luciferase mRNA and novel ionizable lipids for in vivo administration Example 30. Performance of LNP containing novel ionizable lipids in an intravenous mouse model LNP formulations bearing a luciferase mRNA payload and different novel ionizable lipids were compared to the benchmark control for activity in a luciferase mouse model following intravenous administration. At 6h post-dose, novel lipid formulations mediated high levels of luciferase activity in the liver. Some novel lipids reported comparable or superior activity to the benchmark, while others are not as active as the benchmark in this model, but may have utility in other LNP applications (Tables 8-14). Table 8. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 9. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 10. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 11. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 12. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 13. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Table 14. Luciferase activity of 0.5 mg/kg LNP containing firefly luciferase mRNA and various ionizable lipids at 6h following intravenous administration in BALB/c mice (n=4) Example 31. Performance of LNP containing novel ionizable lipids in a dose response study following intravenous administration LNP formulations bearing an OTC mRNA payload and different novel ionizable lipids were compared to the benchmark control for activity in mice following intravenous administration. At 24h post-dose, the novel lipid formulations reported dose-dependent increases in human OTC expression in the liver (Table 15). Table 15. Dose response of LNP containing human OTC mRNA and various ionizable lipids at 24h following intravenous administration in male C57BL/6 mice (n=4) Example 32: Parent ionizable lipid detected in liver at 6 hours following intravenous administration LNP formulations bearing a luciferase mRNA payload and different novel ionizable lipids were compared to the benchmark for amount of ionizable lipid remaining in the liver following intravenous administration. At 6h post-dose, some treatment groups reported lower levels of novel ionizable lipid in mouse liver compared to the benchmark (Tables 16-18). In aggregate, these novel ionizable lipids either show superior activity and/or clearance compared to the control. Table 16. Parent ionizable lipid remaining in liver at 6h following intravenous administration of 0.5 mg/kg Luciferase mRNA LNP in female BALB/c mice (n=4) Table 17. Parent ionizable lipid remaining in liver at 6h following intravenous administration of 0.5 mg/kg Luciferase mRNA LNP in female BALB/c mice (n=4) Table 18. Parent ionizable lipid remaining in liver at 6h following intravenous administration of 0.5 mg/kg Luciferase mRNA LNP in female BALB/c mice (n=4) Example 33. Clearance of LNPs containing novel ionizable lipids following intravenous administration LNP formulations bearing an OTC mRNA payload and different novel ionizable lipids were compared to the benchmark for lipid clearance in the liver following intravenous administration. At various timepoints post-dose, lipid levels were assessed in the liver. Some novel ionizable lipids reported more rapid clearance rates compared to the benchmark (Table 19). Table 19. Parent ionizable lipid remaining in liver following intravenous administration of 0.5 mg/kg human OTC mRNA LNP in male C57BL/6 mice (n=4) Example 34. Particle characteristics of LNP formulations containing novel ionizable lipids LNP formulations containing novel ionizable lipids all produced stable particles with high encapsulation efficiency (Tables 20-23). Table 20. Particle characteristics of LNPs containing EGFP mRNA and novel ionizable lipids for in vivo administration Table 21. Particle characteristics of LNPs containing EGFP mRNA and novel ionizable lipids for in vivo administration Table 22. Particle characteristics of LNPs containing EGFP mRNA and novel ionizable lipids for in vivo administration Table 23. Particle characteristics of LNPs containing EGFP mRNA and novel ionizable lipids for in vivo administration Example 35. Performance of LNP containing novel ionizable lipids in an intravenous mouse model LNP formulations bearing EGFP mRNA payload and different novel ionizable lipids were compared to the benchmark control for activity in an EGFP mouse model following intravenous administration. At 24 h post-dose, novel lipid formulations mediated high levels of EGFP expression in the liver. Some novel lipids reported comparable or superior activity to the benchmark, while others are not as active as the benchmark in this model, but may have utility in other LNP applications (Tables 24-27). Table 24. EGFP expression of 0.5 mg/kg LNP containing EGFP mRNA and various ionizable lipids at 24h following intravenous administration in BALB/c mice (n=4) Table 25. EGFP expression of 0.5 mg/kg LNP containing EGFP mRNA and various ionizable lipids at 24h following intravenous administration in BALB/c mice (n=4)
Table 26. EGFP expression of 0.5 mg/kg LNP containing EGFP mRNA and various ionizable lipids at 24h following intravenous administration in BALB/c mice (n=4) Table 27. EGFP expression of 0.5 mg/kg LNP containing EGFP mRNA and various ionizable lipids at 24h following intravenous administration in BALB/c mice (n=4) Example 36. Parent ionizable lipid detected in liver at 24 hours following intravenous administration LNP formulations bearing EGFP mRNA payload and different novel ionizable lipids were compared to the benchmark for amount of ionizable lipid remaining in the liver following intravenous administration. At 24h post-dose, some treatment groups reported lower levels of novel ionizable lipid in mouse liver compared to the benchmark (Tables 28- 31). In aggregate, these novel ionizable lipids either show superior activity and/or clearance compared to the control. Table 28. Parent ionizable lipid remaining in liver at 24h following intravenous administration of 0.5 mg/kg EGFP mRNA LNP in female BALB/c mice (n=4) Table 29. Parent ionizable lipid remaining in liver at 24h following intravenous administration of 0.5 mg/kg EGFP mRNA LNP in female BALB/c mice (n=4)
Table 30. Parent ionizable lipid remaining in liver at 24h following intravenous administration of 0.5 mg/kg EGFP mRNA LNP in female BALB/c mice (n=4) Table 31. Parent ionizable lipid remaining in liver at 24h following intravenous administration of 0.5 mg/kg EGFP mRNA LNP in female BALB/c mice (n=4) Example 37. Performance of LNP containing novel ionizable lipids in a dose response study following intravenous administration LNP formulations bearing EGFP mRNA payload and different novel ionizable lipids were compared to the benchmark control for activity in mice following intravenous administration. At 24h post-dose, the novel lipid formulations reported dose-dependent increases in EGFP expression in the liver (Table 32). Table 32. Dose response of LNP containing EGFP mRNA and various ionizable lipids at 24h following intravenous administration in female BALB/c mice (n=4) Example 38: Clearance of LNPs containing novel ionizable lipids following intravenous administration LNP formulations bearing EGFP mRNA payload and different novel ionizable lipids were compared to the benchmark for lipid clearance in the liver following intravenous administration. At various timepoints post-dose, lipid levels were assessed in the liver. Some novel ionizable lipids reported more rapid clearance rates compared to the benchmark (Table 33). Table 33. Parent ionizable lipid remaining in liver following intravenous administration of 0.5 mg/kg EGFP mRNA LNP in female BALB/c mice (n=4)
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