CHEN YINGCHUN (CN)
YANG DAN (CN)
CHEN YINGCHUN (CN)
| WO2004046095A1 | 2004-06-03 |
| US3976625A | 1976-08-24 | |||
| US5035969A | 1991-07-30 | |||
| GB1572658A | 1980-07-30 | |||
| US4482627A | 1984-11-13 | |||
| JPH09160251A | 1997-06-20 | |||
| JPS63208843A | 1988-08-30 | |||
| US6368779B1 | 2002-04-09 | |||
| CN1326497A | 2001-12-12 | |||
| US4956260A | 1990-09-11 | |||
| US5015567A | 1991-05-14 |
ORG. LETT., vol. 6, 2004, pages 221 - 224
EUR. J. ORG. CHEM., 2003, pages 4346 - 4348
See also references of EP 1730117A4
| 1. | The N,N'disubstituted thiourea ligand represented by structure I: R4 R5 RiNγN^2 s ' wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are independently for each occurrence alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mRδ0; R3, R4, R5, and R6 are independently for each occurrence H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, (CH2)mR80, CQOR1, (where R^, = alkyl, cycloalkyl, aryl, aralkyl, and (CH2LR80), and CONR11R2 (where Ru or R5, = H, alkyl, cycloalkyl, aryl, aralkyl, and (CH2LR80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 2. | The N,N'disubstituted thiourea ligand of claim 1 , wherein: R1 and R2 are independently for each occurrence 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, and R6are absent; and n = 1 and 2. 3. The N,N'disubstituted thiourea ligand represented by structure II: R3T A R4X A' wherein R1 and R2 are independently for each occurrence alkyl, cycloalkyl, aryl, aralkyl, or (CH2LR80; the A and A1 rings of the biphenyl core independently are unsubstituted or substituted with R. |
| 3. | and R4, respectively, one, two, three, or four times; R3 and R4 are independently for each occurrence H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, Or (CH2LR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 4. | 4 The N,N'disubstituted thiourea ligand of claim 3, wherein: R3 and R4 are absent, and R1 and R2 are independently for each occurrence benzyl, 2,4,6trimethylbenzyl, cyclohexyl or isopropyl. |
| 5. | The N,N'disubstituted thiourea ligand of claim 3, wherein: R3 and R4 are methyl or methoxy, and R1 and R2 are independently for each occurrence benzyl, 2,4,6trimethylbenzyl, cyclohexyl or isopropyl. |
| 6. | The N,N'disubstituted thiourea ligand represented by structure III: R6 wherein R1 and R2 are independently for each occurrence alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; the four aryl rings of the binaphthyl core independently are unsubstituted or substituted with R3, R4, R5, and R6, respectively, any number of times up to the limitations imposed by stability and rules of valence; R3, R4, R5, and R6 are independently for each occurrence H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, or (CH2)mR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 7. | The N,N'disubstituted thiourea ligand of claim 6, wherein: R3, R4, R5, and R6 are absent; R1 and R2 are preferentially selected, independently for each occurrence, from benzyl, 2,4,6trimethylbenzyl, cyclohexyl and isopropyl. |
| 8. | The N.N'disubstituted thiourea ligand represented by structure IV: Ri R~3Xι f ΓRR62 IO R7_ΛS /γR10 R8 R9 IV wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, or (CH2LR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 9. | The N,N'disubstituted thiourea ligand of claim 8, wherein: R1 and R2 are preferentially selected, independently for each occurrence, from 2,4,6mesityl, 2,5difbutylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, and R6 are absent; R7=R8=R9= R10=ethyl, methyl, benzyl, C4H8, C5H10, or C6H12; and n = 1 and 2. 10. |
| 10. | The N,N'disubstituted thiourea ligand represented by structure V: R7Rl V R1 RioψnfR5 R R9 R6 V wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, R10, R11, and R12 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2LR80; an aryl ring independently is unsubstituted or substituted with R13, any number of times up to the limitations imposed by stability and rules of valence; R13 is, independently for each occurrence, H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, or (CH2)mR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 11. | The N,N'disubstituted thiourea ligand of claim 10, wherein: R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, R6, R7, R8, R9, R10, R11, and R12 are absent; R13 are 2,4, 6trimethyl or 2, 4dimethyl; and n = 1 and 2, m=1. 12. |
| 12. | The N,N'disubstituted thiourea ligand of claim 10, wherein: R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, R6, R7, R81 R9, R10 are absent; R13 are absent; and n = 1 and 2, m=0. |
| 13. | The N,N'disubstituted thiourea ligand represented by structure Vl: R3R4 R5 R2NW<\T I AIR11 wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; aryl rings independently are unsubstituted or substituted with R11 and R12, any number of times up to the limitations imposed by stability and rules of valence; R11 and R12 are, independently for each occurrence, H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, or (CH2)mR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 14. | The N,N'disubstituted thiourea ligand of claim 13, wherein: R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, R6, R7, R8, R9, R10 are absent; R11 and R12 are absent; and n = 1 and 2. |
| 15. | The N,N'disubstituted thiourea ligand represented by structure VII: R3R4 R5 R" JL R14L R7' 30 Ri° R12 R r ViI wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; the four aryl rings of a binaphthyl core independently are unsubstituted or substituted with R11, R12, R13, and R14, respectively, any number of times up to the limitations imposed by stability and rules of valence; R11, R12, R13, and R14 are, independently for each occurrence, H, alkyl, cycloalkyl, aryl, aralkyl, halogen, alkoxyl, SiR3, or (CH2)mR80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 16. | The N,N'disubstituted thiourea ligand of claim 15, wherein: R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, R6, R7, R8, R9, R10 are absent; R11, R12, R13, and R14 are absent; and n = 1 and 2. |
| 17. | A method of producing aryl substituted olefins from aryl halides and olefins by a Heck reaction using a palladium catalyst and a N,N'disubstituted thiourea ligand under conditions effective to generate aryl olefins (Scheme 1): Scheme 1 pi transition metal, Ar — x + =/ ligand of the present invention F* X = I, Br, Cl base, >100 0C Ar wherein Ar is an unsubstituted and substituted monocyclic aromatic moiety, or polycyclic aromatic or heteroaromatic moiety; X is Cl, Br, I, OS(O)2alkyl, OS(O)2aryl Or SO2CI; R is H, alkyl, aryl, heteroaryl, aralkyl, alkyoxyl, amino, or trialkylsilyl; the transition metal is a Group VIIIA metals (Pd(dba)2, Pd(OAc)2, PdCI2 , PdCI2 (CH3CN)2, or NiCI2, Ni(COD)2); the base is a carbonate, an acetate, a fluoride, a trialkylamine, a phosphate, an alkoxide, or an amide; the N,N'disubstituted thiourea ligand is one of structures 18 inclusive: R4 Rs RafφP6 S Λ wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, and R6 are, independently for each occurrence, H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, (CH2)mR80, CQQR,, (where R1 = alkyl, cycloalkyl, aryl, aralkyl, and (CH2LR80), or CONR11R1. (where Ru or Rj, = H, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; wherein A and A' independently represent fused rings of monocyclic or polycyclic cycloalkyls, cycloalkenyls, aryls, or heterocyclic rings, the rings having 4 to 8 backbone atoms; R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, and R6, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R7 and R8, for each occurrence, independently represent halogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; A and A' independently are unsubstituted or substituted with R7 and R8, respectively, any number of times up to the limitations imposed by stability and the rules of valence; R3 and R5, or R4 and R6, or both, taken together optionally represent a ring having 57 atoms in the backbone of the ring; the ring having zero, one or two heteroatoms in its backbone; and being subsitituted or unsubstituted; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; wherein R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, and R10, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; wherein R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, and R10, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate. carbonvl cqrboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfoπyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; the A and A' rings of the binaphthyl core independently are unsubstituted or substituted with R7 and R8, respectively, any number of times up to limitations imposed by stability and the rules of valence; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R3XjJ5R6 R1N^VR2 ?10 R7 R8A /v R1 I R 399 5 wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are selected, independently for each occurrence, from the groups consisting of alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, R10are, independently for each occurrence, H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, (CH2)mR80, COOR1. (where R, = alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80), and CONRUR. (where Rn or R5, = H, alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. pVN N 1 \_J S M— N^^N—R2 R R9 R6 6 wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, R10, R11, and R12 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; Aryl ring independently is unsubstituted or substituted with R13, any number of times up to the limitations imposed by stability and rules of valence; R13 is, independently for each occurrence, hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R3R4 RS R2N( ynX fl A^R11 R12 A1 wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; Aryl rings independently is unsubstituted or substituted with R11 and R12, any number of times up to the limitations imposed by stability and rules of valence; R11 and R12 are, independently for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R3R4 R5 R11 R2NO\T [f /f ^LR13 F T ~ s s ^ l Ji R14÷: r Λ'Ji R7 "!ALJΛ?NR~1R°1 R12 R R^ g wherein n is an integer in the range of 1 to 8 inclusive; R3 RΦ R5. R6. R7. R8, R9. and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; the four aryl rings of the binaphthyl core independently are unsubstituted or substituted with R11, R12, R13, and R14, respectively, any number of times up to the limitations imposed by stability and rules of valence; R11, R12, R13, and R14 are selected, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 18. | The method of claim 17, wherein the N,N'disubstituted thiourea ligand is structure 1 ; the transition metal is palladium; and the base is trialkyl amine, acetates, fluorides, carbonates, phosphate, hydroxides, and amides. |
| 19. | The method of claim 18, wherein R1 and R2 are preferentially selected, independently for each occurrence, from 2,4,6mesityl, 2,5difbutylphenyl, 2,6diethylphenyl and fbutyl; R3, R4, R5, and R6 are absent; and X represents I, Br, or Cl; R represents alkyl, aryl, heteroaryl. |
| 20. | The method of claim 17, wherein the N,N'disubstituted thiourea ligand is structure 5; the transition metal is palladium; and the base is trialkylamine, acetates, fluorides, carbonates, phosphate, hydroxides, and amides. |
| 21. | The method of claim 20, wherein R1 and R2 are preferentially selected, independently for each occurrence, from 2,4,6mesityl, 2,5difbutylphenyl, 2,6diethylphenyl and fbutyl; R3, R4, R5, and R6 are absent; R7=R8=R9= R10=ethyl, methyl, benzyl, C4H8, C5H10, C6H12; n = 1 ; X represents I, Br, or Cl; R represents alkyl, aryl, heteroaryl. |
| 22. | The method of claim 17, wherein the N,N'disubstituted thiourea ligand are structure 6; the transition metal is palladium; and the base is trialkylamine, acetates, fluorides, carbonates, phosphate, hydroxides, and amides. |
| 23. | The method of claim 22, wherein R1 and R2 are preferentially selected, independently for each occurrence, from 2,4,6mesityl, 2,5difbutylphenyl, 2,6diethylphenyl and fbutyl; R3, R4, R5, R6, R7, R8, R9, R10 are absent; R13 are absent; n = 1 , m=0; X represents I, Br, or Cl; R represents alkyl, aryl, heteroaryl. |
| 24. | The method of claim 23, wherein the yield of ArCH=CHR is between about 50 and about 99%. |
| 25. | The method depicted in Scheme 2: Scheme 2 transition metal, Ar__x + Ar1B(OH)2 ligand of the present invention Ar _Ar, base wherein Ar and Ar1 are independently selected from the group consisting of unsubstituted or substituted monocyclic or polycyclic aromatic or heteroaromatic moieties; X is Cl, Br, I1 OS(O)2alkyl, OS(O)2aryl, Or SO2CI ; the transition metal is a Group VIIIA metal (Pd(dba)2, Pd(OAc)2, PdCI2 and NiCI2, Ni(COD)2); the base is a carbonate, an acetate, a trialkylamine, a phosphate, or an alkoxide; the N,N'disubstituted thiourea ligand is one of structures 18 inclusive: R4 R5 R' lJH(>nR R1'NγNR2 S 1 wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, and R6 are, independently for each occurrence, H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, (CH2)mR80, COOR1, (where R,, = alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80), or CO_NRuRj, (where Ru or Ru = H, alkyl, cycloalkyl, aryl, aralkyl, and (CH2XnR80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R8 wherein A and A' independently represent fused rings selected from the group consisting of monocyclic or polycyclic cycloalkyls, cycloalkenyls, aryls, and heterocyclic rings, said rings having 4 to 8 backbone atoms; R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, and R6, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R7 and R8, for each occurrence, independently represent halogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; A and A' independently are unsubstituted or substituted with R7 and R8, respectively, any number of times up to the limitations imposed by stability and the rules of valence; R3 and R5, or R4 and R6, or both, taken together optionally represent a ring having 57 atoms in the backbone of said ring; said ring having zero, one or two heteroatoms in its backbone; and said ring is substituted or unsubstituted; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R8" y R4 R6 wherein R1 and R2are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, and R10, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N.N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; wherein R1 and R2 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, and R10, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CHyR80; the A and A' rings of the binaphthyl core independently are unsubstituted or substituted with R7 and R8, respectively, any number of times up to limitations imposed by stability and the rules of valence; R80 represents independently for each occurrence unsubstituted of substituted aryl, cycloalkyl, cycloalkenyl, or polycyclyl; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R3X?R6 R7_jAs /Y R1° R8 R9 5 wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; R3, R4, R5, R6, R7, R8, R9, R10are, independently for each occurrence, H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, (CH2)mR80, COOR1, (where R, = alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80), or CONR11R, (where Ru or Ry = H, alkyl, cycloalkyl, aryl, aralkyl, and (CH2)mR80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; □ 7 R4 R R9 R6 6 wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, R10, R11, and R12 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; the aryl ring independently is unsubstituted or substituted with R13, any number of times up to the limitations imposed by stability and rules of valence; R13 is selected, independently for each occurrence, for each occurrence, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; R3R4 R5 R2N^T_ f| A4— R11 S R12_J_A' wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; aryl rings independently are unsubstituted or substituted with R11 and R12, any number of times up to the limitations imposed by stability and rules of valence; R11 and R12, independently for each occurrence, represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer; or R3 R4 R5 R11 R2~Nw IJ \ C> s13 R7IrWRiO R12 R R9 g wherein n is an integer in the range of 1 to 8 inclusive; R3, R4, R5, R6, R7, R8, R9, and R10 are, independently for each occurrence, alkyl, cycloalkyl, aryl, aralkyl, or (CH2)mR80; the four aryl rings of the binaphthyl core independently are unsubstituted or substituted with R11, R12, R13, and R14, respectively, any number of times up to the limitations imposed by stability and rules of valence; R11, R12, R13, and R14 are, independently represent hydrogen, alkyl, alkenkyl, alkynyl, alkoxyl, silyloxy, nitro, alkylthio, amide, phosphoryl, phosphonate, carbonyl, carboxyl, carboxamide, silyl, alkylsulfonyl, arylsulfonyl, selenoalkyl, ketone, aldehyde, guanidine, amidine, acetal, ketal, amine oxide, aryl, azide, carbamate, imide, oxime, sulfonamide, urea, or (CH2)R80; R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or another polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the N,N'disubstituted thiourea ligand, when chiral, is a mixture of enantiomers or a single enantiomer. |
| 26. | The method of claim 25, wherein the N,N'disubstituted thiourea ligand is structure 1; the transition metal is palladium; and the base is trialkylamine, acetates, carbonates or phosphate. |
| 27. | The method of claim 26, wherein R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dk butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, and R6 are absent; X represents I, Br, or SO2CI; and Ar and Ar' represent aryl, or heteroaryl. |
| 28. | The method of claim 25, wherein the N,N'disubstituted thiourea ligand is structure 5; the transition metal is palladium; and the base is a trialkylamine, an acetate, a fluoride, a carbonate, a phosphate, a hydroxide, or an amide. |
| 29. | The method of claim 28, wherein R1 and R2 are, independently for each occurrence, 2,4,6mesityl, 2,5dif butylphenyl, 2,6diethylphenyl or fbutyl; R3, R4, R5, and R6 are absent; R7=R8=R9= R10=ethyl, methyl, benzyl, C4H8, C5H10, C6H12; n = 1 ; and X represents I, Br, or SO2CI; Ar and Ar' represent aryl or heteroaryl. |
| 30. | The method of claim 25, wherein the N,N'disubstituted thiourea ligand is structure 6; the transition metal is palladium; and the base is a trialkylamine, an acetate, a fluoride, a carbonate, a phosphate, a hydroxide, or an amide. |
| 31. | The method of claim 30, wherein R1 and R2 are preferentially selected, independently for each occurrence, from 2,4,6mesityl, 2,5difbutylphenyl, 2,6diethylphenyl and t butyl; R3, R4, R5, R6, R7, R8, R9, R10 are absent; R13 is absent; n = 1 , m=0; X represents I1 Br, or SO2CI; and Ar and Ar' represent aryl or heteroaryl. |
| 32. | The method of claim 31 , wherein the yield of ArAr' is between about 50% and about 99%. |
This application claims priority of provisional application u.s. serial no. 60/556,570, filed March 26, 2004, the contents of which are being incorporated herein by reference.
FIELD OF THE INVENTION This invention relates to thiourea ligands and more particularly to thiourea-palladium complexes useful as catalysts for palladium catalyzed arylation of alkenes in a chemical reaction known as the Heck reaction, and as catalysts for palladium catalyzed Suzuki reactions of organoboric compounds and aryl halides.
BACKGROUND OF THE INVENTION The palladium catalyzed arylation of olefins (the Heck reaction) is one of the most versatile tools for C-C bond formation in organic synthesis.111 Phosphine ligands are generally used to stabilize the reactive palladium intermediates, and excellent results have been reported for Pd-catalyzed Heck reactions when sterically bulky mono-phosphines, diphosphines, cyclometalated phosphines, or phosphites are used as the ligands.12"51 The air- sensitivity of phosphine ligands, however, places significant limits on their synthetic applications. Therefore, the development of phosphine-free palladium catalysts is a topic of enormous interest. [6"8] Thioureas are air and moisture stable solids and have recently been employed as ligands in Ru-, Rh-, or Pd-catalyzed reactions.19'101 Very recently, Z. Yang[11] and coworkers reported the Heck and Suzuki reactions of highly active arenediazonium salts catalyzed by a chiral thiourea -Pd complex.
SUMMARY OF THE INVENTION The invention provides thiourea-Pd(O) complexes that are air and moisture stable, highly active catalysts for the Heck reactions of aryl halides. More particularly, the invention provides the N,N'-disubstituted monothiourea ligand represented by generic structure I: R4 R , 5_ R3^-φ-nR6 RrNγN^R2 s ' wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are selected, independently for each occurrence, from the groups consisting of alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80; R3, R4, R5, and R6 are selected, independently for each occurrence, from the groups consisting of H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, -(CH2)m-R80, COQR1, (where R1 = alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80), and CONR11R1, (where Ru or R1 = H, alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the ligand, when chiral, is a mixture of enantiomers or a single enantiomer.
The bis-thiourea ligand represented by generic structure Ii: R4 R5, R H^ Rb R1_NΛ 'n \_R2 R7- A s^YR1° R8 R9 Il wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are selected, independently for each occurrence, from the groups consisting of alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80; R3, R4, R5, R6, R7, R8, R9, and R10 are selected, independently for each occurrence, from the groups consisting of H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, -(CH2)m-R80, COOR1, (where Ry = alkyl, cycloalkyl, aryl, aralkyl, and -(CH2L-R80), and CONRUR, (where Ru or R1 = H, alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the ligand, when chiral, is a mixture of enantiomers or a single enantiomer.
The bis-thiourea ligand represented by generic structure III: R7 R4 fA-N N-.Ri R13/=V \_Y s M-N N-R2 5 RioWn TRr R9 R6 wherein n is an integer in the range of 1 to 8 inclusive; R1 and R2 are selected, independently for each occurrence, from the groups consisting of alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m-R80; R3, R4, R5, R6, R3, R5, R6, R7, R8, R9, R10, R11, R12, R13 are selected, independently for each occurrence, from the groups consisting of H, alkyl, halogenated alkyl, cycloalkyl, aryl, aralkyl, - (CH2)m-R80, COOR, (where R5, = alkyl, cycloalkyl, aryl, aralkyl, and -(CH2)m- R80), and CONRUR, (where Ru or R1 = H, alkyl, cycloalkyl, aryl, aralkyl, and - (CH2)m-R80); R80 represents unsubstituted or substituted aryl, cycloalkyl, cycloalkenyl, or polycycle; m is independently for each occurrence an integer in the range of 0 to 8 inclusive; and the ligand, when chiral, is a mixture of enantiomers or a single enantiomer. BRIEF DESCRIPTION QF THE DRAWINGS
Figure 1 shows some representative structures of thiourea ligands I.
Figure 2 shows some representative structures of thiourea ligands II.
Figure 3 shows some representative structures of thiourea ligands III.
Figure 4 shows structures of cis- and fra/?s-PdCI2 (1g)2- (Hydrogen atoms have been omitted for clarity. Thermal ellipsoids are shown at 30% probability). DETAILED DESCRIPTION OF THE PREFERRED EMBOniMFNTS
The invention provides acyclic and cyclic thioureas 1a-q (Figures 1 -3)
and complexes thereof with Pd(O) or Pd(II) (Figure 4), which serve as
catalysts for the Heck reaction between iodobenzene and methyl acrylate at
100 0C (Table 1).
Table 1. Screening thiourea ligands for the Pd-catalyzed Heck reaction of iodobenzene with
methyl acrylate3
Pd(dba)2/ligand ArI + ^-CO2Me .- ^^/CO2Mr- A ArrlI + + N NEEtt33,, D DWMIFF A Arr ^" 100 ° C
Pd time entry ligand yield" TON (mol%) (h) 1 1e 0.1 1 >99 103 2 ig 0.01 2 >99 104 3 1 h 0.01 2 >99 104 4 1 i 0.01 1.5 >99 104 5 11 0.01 6 86 8.6x103 6 1n 0.01 4 95 9.5x103 7 1o 0.01 4 45 4.5x103 8 1P 0.01 4 99 104 9 iq 0.01 2 99 104 10 1i 0.0001 48 50 5x105 11° 1n 0.001 0.5 99 105 1 2d iq 0.0002 5 99 5x105 13d 1n 0.0001 12 99 106 " Reactions were conducted under aerobic conditions. ° Yield was determined by 1H NMR spectroscopy using nitrobenzene as the internal standard. c At 1500C. d At 1800C under solvent- free condition
The reactions were conducted in air and that all the reagents were
used directly as received. The structure of each thiourea ligand has a great
influence on the catalytic efficacy of its palladium complex. Acyclic thioureas
1a-c were almost completely inactive, as was also the case for the cyclic
thiourea 1d featuring an NH moiety. Good activity was observed, however,
when using the Λ/,ΛT-disubstituted bulky thioureas 1e-1q of different ring sizes
as the ligands (Table 1 entries 1-8); the catalyst loading could be lowered down to 0.0001 mol%. The reaction also could be conducted at high temperature under solvent-free conditions without affecting the catalytic efficacy (entries 12 and 13).
The catalytic efficacy of the thiourea Ig-Pd(O) and Iq-Pd(O) complex in the Heck reaction was studied further with a number of aryl halides and olefins at 100-130°C. Table 2 indicates that high yields were obtained using 0.01 mol% Pd catalyst for olefins such as butyl acrylates (entries 1 -2), Olefins that are α- or β-subsituted are also suitable substrates and give trisubstituted olefins,1121 but higher catalyst loadings and reaction temperatures were required (entries 3-4). In general, higher catalyst loadings and temperatures were required to force the completion of the reactions of the aryl bromides compared to the case of aryl iodides (entries 5-8). 3-Bromopyridine was also efficiently coupled with styrene in 90% yield in the presence of 0.1 mol% of Pd (entry 9). The deactivated bromide could be coupled at higher temperature (entry 10, 1600C).
Table 2. Heck reaction of aryl iodides anc i bromides with i olefins8 R2 Pd(dba)2/1 g or 1 q ArX + / base, solvent RwR2 R1 Pd time yield entry ligand ArI 1 ig PhI Λ (mol%) (h) (%)" ^^CO-2Bu° 0.01 2 99 2 iq 0.01 3 99 3 ig PhI 1 10 88 4 iq HsCO-f^ y-\ ^CO2Me 0.5 5 68 5 ig ^-a- COOMe 0.1 15 92 6 ig }-Br Ph 0.1 15 99 7 ig PhBr Ph 0.1 24 74 8 iq COOBu" 0.1 10 99 9 ig Ph 0.1 24 90 10 iq Ph 0.5 24 76
Beller[13] reported that the Heck reactions of aryl chlorides could be greatly improved when using Bu4NBr as an ionic liquid solvent.1141 In fact, this system is also suitable for the thiourea 1g-Pd(0)-catalyzed Heck reactions of deactivated bromides and activated chlorides, when the reaction temperature is elevated slightly. The results were summarized in Table 3. Excellent yields were achieved for deactivated bromides after their reaction for 24 h in the presence of 0.5 mol% of Pd (entries 1-3), but incomplete conversion occurred when using 0.2 mol% Pd catalyst (entry 4). Under the same conditions, activated aryl chlorides were coupled successfully with styrene within 24 h when using 1 mol% of the Pd catalyst (entries 5-7). n-Butyl acrylate displayed reactivity that was slightly lower than that of styrene, but good yields were also obtained (entries 8-10). Chorobenzene itself, however, was completely inert, even when we used a higher loading of the Pd catalyst (2 mol%) (entry 11 ).
Table 3. Heck reactions of deactivated bromides and activated chlorides with olefins Pd(dba)2/1g R ArX + = =y NaOAc, TBAB Ar/ 135 0C Pd time yield entry ArX R (mol%) (h) (%)b 1 H3CO- 4^ f~Br Ph 0.5 24 99 2 H3CO-^J)-Br COOnBu 0.5 24 99 3 X-O-BΓ COOnBu 0.5 24 97 4 H3CO-^ V-Br Ph 0.2 30 80 5 H3COC-^V-CI Ph 1 24 96 6 H3COC-^ V-Cl Ph 0.5 30 67 7 Ph 1 24 99 8 H3coc-^~^-cι COO11Bu 2 24 77 9 PhOC- ^ /~cl COO11Bu 1 24 80 10 cc, COO11Bu 1 24 90 11 σa Ph 2 24 <5
The Pd-catalysed Suzuki cross-coupling reaction of aryl halides with aryl boric acids provides a general and efficient synthetic route to biaryl compounds and has found wide application in many areas of organic synthesis. [15] The operationally simple and air-stable catalytic system of thiourea-Pd catalyst inspired us to investigate its scope in Suzuki reaction. As revealed in Table 4 using 1q as the ligand, for p-iodoanisole, excellent isolated yield was obtained at a loading of 0.01 mol% Pd at 100°C after 3h under aerobic conditions (Table 3, entry 1 ).
Encouraged by the result, we began to evaluate the coupling reaction of aryl bromides with aryl boric acids. For activated bromides, almost quantitative yields were achieved within 3h in the presence of 0.1 mol% Pd under the same conditions (entries 2-6 ). On the other hand, low yield was obtained when deactivated p-bromoanisole was applied at 0.5 mol% Pd at 120°C (entry 7), and similar results were gained when a bulky monodentate 1i was used (entry 8). However, the yield could be increased adding 20 mol% TBAB (entry 9). For 3,5-difluorophenylboric acid, better result could be obtained when the reaction was conducted in neat TBAB (entry 10). Acceptable yield was achieved for p- nitrochlorobenzene at 1 mol% Pd adding 20 mol% TBAB (entry 11 vs 12). Notably 1-bromostyrene also displayed high reactivity to phenylboric acid in thiourea-Pd system (entry 13). Moreover, potassium aryl trifluoroborates[16J have been found to be more reactive than the corresponding organoboric acid, and high yields were obtained at only 0.1 mol% Pd at 1000C (entries 14 and 15). We also conducted the Suzuki reaction at further decreased catalyst loading (0.01 mol%), and quantitative yield was obtained for 3-nitro-bromobenzene at 120°C in 3h (entry 16).
Table 4. Suzuki coupling reaction catalyzed by 1q-Pd(dba)2 Pd(dba)2-1q ArX + Ar1B(OH)2 Ar-Ar1 K2CO3 , NMP, H2O Entr Pd T t Yield Ar1X Ar2B(OH)2 y (mol%) ("C) (h) (%) 1 H3CO- <f \ — I PhB(OH)2 0.01 100 3 92 2 OHC→Q^BΓ PhB(OH)2 0.1 100 3 92° 3 lr PhB(OH)2 0.1 100 3 90 4 PhB(OH)2 0.1 100 99 f VB(OH)2 5 0.1 100 97 6 J^)-B(OH)2 0.1 100 VJT"BΓ 2 99 7 PhB(OH)2 0.5 120 10 33 8 C PhB(OH)2 0.5 120 10 27 9 d PhB(OH)2 0.5 120 12 67 10 e <^ V-B(OH)2 0.5 130 12 51 11 ' PhB(OH)2 1 130 40 10 12 *' PhB(OH)2 1 130 24 49 13 PhB(OH)2 0.1 100 1 80 O2N-T== 14 \_JΓS' PhBF3K 0.1 100 1 99 15 OHc-/ ff~B' PhBF3K 0.1 100 1.5 87 O1N-,.= 16 \\ /)-Br PhB(OH)2 0.01 120 3 99 In conclusion, the palladium complexes of cyclic and acyclic thiourea
demonstrated high thermal stability and excellent catalytic activity in Heck and
Suzuki coupling reactions under aerobic conditions. Remarkable TONs and
TOFs were achieved in the coupling reactions (TONs up to 1 ,000,000, TOFs
up to 200,000, for the reaction of PhI and n-butyl acrylate).
Example 1.
Synthesis of cyclic thioureas 1f-1k:
glyoxal NaBH(OAc)3 Ar-NH2 Ar-N7 XN-Ar C2H5OH/H2O CH2CI2, reflux 80-93% 60-90%
Method A 1 ,1'-Thiocarbonyldiimidazole toluene, 100 0C Ar-N NUAr Ar-NH HN-Ar S Thiophosgene 1f: Ar=4-MeO-Ph 1 g: Ar=Mesityl Method B Na2CO3, THF 1 h: Ar=2,6-Et2-Ph 1 i: Ar=2,5-BuVPh
Method A -N -N H n\ // 75% v^ ^
H3CO y prιϋMU t H3cσ NHBn Method B ^. H H3rCnO. H3CO NH2 NaBH(OAc)3 H3CO NHBn 85o/o H3CO. 90%
Scheme 1
Two methods were used for the synthesis of cyclic thiourea ligands (Scheme
1 ). Method A: To a Λ/,Λ/ -diaryl diamine solution in dry toluene was added 1 ,1 '- thiocarbonyl diimidazole (1.2 equiv). Then the solution was stirred at 100°C and the reaction was monitored by TLC. After completion, the solution was diluted with ethyl acetate and washed with dilute HCI and brine. The organic layer was concentrated under vacuum. The pure thiourea was obtained through flash chromatography or recrystallization from 95% ethanol.
Method B: To a stirred mixture of /V,Λ/'-diaryl diamine and Na2CO3 (1.5 equiv) in dry THF was added a solution of thiophosgene (1.2 equiv) in THF dropwise at room temperature. After stirring at room temperature overnight, water and ethyl acetate were added. The organic layer was washed with dilute HCI and brine, dried and concentrated. The pure thiourea was obtained through flash chromatography or recrystallization from 95% ethanol.
Preparation of 1f: Using method A; 75% yield. M.p. 167-168 °C; 1H NMR (300 MHz, CDCI3) δ 7.42 (d, J = 9.0 Hz, 4H), 6.95 (d, J = 9.0 Hz, 4H), 4.08 (s, 4H), 3.81 (s, 6H); 13C NMR (75 MHz, CDCI3) δ 182.2, 158.1 , 138.8, 127.5, 114.2, 55.4, 49.8; IR (cm"1): 151 1 , 1443, 1285; LRMS (El): 314 (M+, 100); HRMS (El): calcd for C17H18N2O2S (M+) 314.1089, found 314.1088.
Preparation of 1g: Using method B; 85% yield. M.p. 218-218.5 °C; 1H NMR (400 MHz, CDCI3) δ 6.91 (s, 4H), 3.94 (s, 4H), 2.26 (s, 6H), 2.24 (s, 12H); 13C NMR (75 MHz, CDCI3) δ 181.1 , 138.2, 136.6, 134.5, 129.5, 47.6, 21.1 , 17.8; IR (cm"1): 1488, 1331 , 1271 ; LRMS (FAB): 339 (M++1 , 100); HRMS (FAB): calcd for C21H26N2S (M++1 ) 339.1894, found 339.1879.
Preparation of 1h: Using method B; 70% yield. M.p. 152-153 0C; 1H NMR (300 MHz, CDCI3) δ 7.32 (t, J = 6.6 Hz, 2H), 7.20 (d, J = 7.5 Hz, 4H), 4.02 (s, 4H), 2.80- 2.70 (m, 4H), 2.69-2.60 (m, 4H), 1.33 (t, J = 7.5 Hz, 12H); 13C NMR (75 MHz, CDCI3) δ 182.6, 142.5, 136.1 , 128.8, 126.5, 49.1 , 24.0, 14.4; IR (cnτ1): 1484, 1285; LRMS (El): 366 (M+, 39), 337 (100); HRMS (El): calcd for C23H30N2S (M+) 366.2130, found 366.2120.
Preparation of 1i: Diimine: 92% yield. 1H NMR (300 MHz, CDCI3) δ 8.27 (s, 2H), 7.35 (d, J = 8.3 Hz, 2H), 7.25 (d, J = 8.3 Hz, 2H), 6.86 (s, 2H), 1.43 (s, 18H), 1.34 (s, 18H); 13C NMR (75 MHz, CDCI3) δ 158.6, 150.1 , 150.0, 140.4, 126.0, 123.8, 116.0, 35.3, 34.4, 31.3, 30.5; IR (cm"1): 1609, 1492, 1265; LRMS (El): 432 (M+, 100); HRMS (El): calcd for C30H44N2 (M+) 432.3504, found 432.3504. Diamine: 90% yield. 1H NMR (300 MHz, CDCI3) δ 7.18 (d, J = 6.1 Hz, 2H), 6.80 (s, 2H), 6.75 (d, J = 6.1 Hz, 2H), 4.18 (br s, 2H, NH), 3.57 (s, 4H), 1.39 (s, 18H), 1.32 (s, 18H); 13C NMR (75 MHz, CDCI3) δ 149.9, 146.2, 131.2, 126.0, 114.6, 110.0, 45.0, 34.4, 33.8, 31.4, 30.2; IR (crrT1): 3688, 3601 , 1561 , 1265; LRMS (El): 436 (M+, 20), 219 (100); HRMS (El): calcd for C30H48N2 (M+) 436.3817, found 436.3817. Thiourea Ii was prepared using method B. A solution of Thiophosgene in dilute THF must be dropped very slowly. 1i was isolated as a white solid (75% yield) after flash chromatography on silica gel. M.p. 212-214 0C; 1H NMR (400 MHz, CDCI3) δ 7.45 (d, J = 8.5 Hz, 2H), 7.32 (d, J = 8.5 Hz, 2H), 7.02 (s, 2H), 4.06-4.03 (m, 2H), 3.93-3.91 (m, 2H), 1.50 (s, 18H), 1.30 (s, 18H); 13C NMR (100 MHz, CDCI3) δ 183.5, 150.4, 145.0, 140.8, 128.0, 127.8, 125.3, 53.4, 35.4, 34.3, 32.1 , 31.3; IR (cm"1): 1418, 1275; LRMS (FAB): 479 (M+ + H); FAB-HRMS: calcd for C31H46N2S (M+ + H) 479.3460, found 479.3460.
Preparation of 1j: Using method A, 75% yield. M.p. 173-174 0C; 1H NMR (300 MHz, CDCI3) δ 7.41-7.15 (m, 10H), 3.82-3.77 (m, 4H), 2.32-2.24 (m, 2H); 13C NMR (75 MHz, CDCI3) δ 180.7, 147.4, 129.2, 127.4, 125.8, 51.4, 22.3; IR (cm"1): 1494, 1285; LRMS (El): 268 (M+, 73); EI-HRMS: calcd for C16H16N2S (M+) 268.1034, found 268.1015. Preparation of 1k: To a stirred suspension of racemic 2,2'-diamino-6,6'-dimethoxy- biphenyl2 (60mg, 0.25 mmol) and NaBH(OAc)3 (212 mg, 1 mmol) in dichloromethane (10 mL) was added a solution of benzaldehyde (0.06 ml, 0.58 mmol) in dichloromethane (2 mL) dropwise at room temperature. Then the mixture was stirred overnight. Flash chromatography on silica gel gave Λ/,Λ/-dibenzyl diamine as a white solid (94 mg, 90%). 1H NMR (300 MHz, CDCI3) δ 7.26-7.11 (m, 12H), 6.38 (d, J = 8.2 Hz, 2H), 6.32 (d, J = 7.7 Hz, 2H), 4.32 (s, 4H), 4.17 (br s 2H), 3.70 (s, 6H); 13C NMR (75 MHz, CDCI3) δ 158.1 , 147.3, 139.9, 129.6, 128.4, 126.7, 126.6, 107.2, 104.2, 100.6, 55.7, 47.5; IR (cm"1): 3432, 3086, 3051 , 2938, 1586, 496, 1472, 1422, 1282, 1131 ; LRMS (El): 424 (M+, 33), 333 (100); HRMS (El): calcd for C28H28N2O2S (M+) 424.2151 , found 424.2138. Thiourea 1k was prepared using method B, 85% yield. M. p. 179-180 0C; 1H NMR (400 MHz, CDCI3) δ 7.27 (t, J = 8.2 Hz, 2H), 7.04-7.00 (m, 6H), 6.88 (d, J = 8.2 Hz, 2H), 6.83-6.80 (m, 6H), 5.72 (d, J = 15.3 Hz, 2H), 4.81 (d, J = 15.3 Hz, 2H), 3.75 (s, 6H); 13C NMR (75 MHz, CDCI3) δ 199.6, 157.2, 147.7, 137.1 , 128.7, 127.9, 127.5, 126.7, 121.8, 113.9, 108.8, 56.8, 55.9; IR (cm"1): 3051 , 1592, 1579, 1464, 1420, 1245, 1190; LRMS (El): 466 (M+, 100), 375 (86); HRMS (El): calcd for C29H26N2O2S (M+) 466.1715, found 466.1718. Example 2. Synthesis of acyclic bis-thiourea ligands: glyxoal NaBH(OAc)3 Thiophosgene Ar-NH2 Ar-N7 XN-Ar Ar-NH HN-Ar C2H5OH/H2O DCM, reflux Et3N, DCM
Ar-N N-Ar 11 piperidine 1 m Ar-N N-Ar A /ϊQ 11: Ar=2,5-Bu'2-Ph 1m, 1n: Ar=Mesityl Cl A S A S Cl Ar-N N-Ar diethylamine 1n
Scheme 2
A solution of /V,/V'-diaryl diamine (1.0 mmol) and NEt3 (3 equiv) in THF was dropped to a stirred solution of thiophosgene (3.0 equiv) in dry THF at 0 0C. After stirred at room temperature overnight, the organic layer was washed with water, dried and concentrated. For the synthesis of acyclic bis-thiourea, the dichloride obtained above and excess secondary amine were heated at 100 0C in a sealed pressure tube for 24 hours. Then the solution was diluted with EtOAc and washed with dilute HCI and brine. The organic layer was dried and concentrated. Flash chromatography gave the pure bis-thiourea as a white solid.
11: White solid, 95 % yield; m.p 225-226 0C; 1H NMR (400 MHz, CDCI3) δ 7.37-7.34 (m, 2H), 7.21-7.18 (m, 2H), 7.18-7.00 (m, 2H), 4.87-4.79 (m, 2H), 4.15-4.11 (m, 2H), 3.54-3.35 (m, 8H), 1.44-1.19 (m, 48H); 13C NMR (100 MHz, CDCI3) δ 190.0, 149.1 , 142.9, 141.3, 129.8, 127.4, 124.1 , 54.0, 52.5, 35.6, 34.0, 32.0, 31.1 , 25.2, 24.2; IR (cm"1): 2958, 2865, 1609, 1440, 1397, 1362, 1244, 1185, 1133, 1026; ESI LRMS: 690(M, 2), 359(100); El HRMS: ca led for C42H66N4S2690.4729, found 690.4717.
1m: White solid, 40 % yield for two steps; m.p 222-224 0C; 1H NMR (400 MHz, CDCI3) δ 6.83 (s, 4H), 4.29 (s, 4H), 3.30-3.27 (m, 8H), 2.25 (s, 6H), 2.18 (s, 12H), 1.39-1.36 (m, 4H), 1.17-1.15 (m, 8H); 13C NMR (100 MHz, CDCI3) δ 188.3, 141.3, 136.1 , 134.3, 130.0, 51.9, 50.9, 25.2, 24.2, 20.7, 19.1 ; IR (cm"1): 2934, 2851 , 1609, 1473, 1422, 1369, 1245, 1185, 1159, 1131 , 1027; El LRMS: 550 (M, 34), 152 (100); El HRMS: calcd for C32H46N4S2550.3164, found 550.3158.
1n: White solid, 38 % yield for two steps; m.p 197-199 0C; 1H NMR (400 MHz, CDCI3) δ 6.82 (s, 4H), 4.29 (s, 4H), 3.30 (q, J = 6.8 Hz, 8H), 2.24 (s, 6H), 2.21 (s, 12H), 0.73 (t, J = 6.8 Hz, 12H); 13C NMR (100 MHz, CDCI3) δ 189.9, 141.6, 136.4, 135.0, 51.3, 46.0, 20.8, 19.2, 11.7; IR (cm'1): 2963, 2929, 1651 , 1486, 1441 , 1411 , 1370, 1348, 1274, 1223, 1185, 1152, 1120, 1081 , 1013; El LRMS: 526 (M, 42), 277 (100); El HRMS: calcd for C30H46N4S2526.3164, found 526.3168. Example 3 Synthesis of cyclic bis-thiourea ligand 1o: o / ,o .ri. NH3 ^ /r\ kl<- THF, reflux / \ -NH O- NH \ I)LAW NH2 Methanol NH NH2 HCI 2)HC1
Br N rhH\N Br Na2CO3JHF NHHN \_/ 1o Preparation of 1o: To a stirred mixture of diamine salt (2.Og, 9.2mmol) and Na2CO3 (0.85g, 8mmol) in CH3CN (15 ml) was added slowly a solution of Bis(bromomethy)mesitylene (0.72g, 2.3mmol) in CH3CN (10 ml) at 810C. The resulting mixture was refluxed for 24h. Then the mixture was diluted with ethyl acetate and washed with brine, dried and concentrated. The resulting oil was dissolved in THF (30ml) and Na2CO3 (1.27g, 12mmol) was added. Thiophosgene (0.7ml, 9mmol) in THF (10 ml) was dropped very slowly at room temperature. After stirred overnight, THF was removed, and water (20 ml) and ethyl acetate (40 ml) were added. The organic layer was washed with dilute HCI and brine, dried and concentrated. The pure bis-thiourea 1o was obtained through flash chromatography (20% ethyl acetate/petroleum ether) as a white solid (150mg, 11 %).
1o: m.p >230 0C; 1H NMR (400 MHz, CDCI3) δ 6.97 (s, 1 H), 6.95 (s, 4H), 4.97 (s, 4H), 3.66 (t, J=8.4 Hz, 4H), 3.41 (t, J = 8.4 Hz, 4H), 2.43 (s, 3H), 2.40 (s, 6H), 2.29 (s, 6H), 2.22 (s, 12H); 13C NMR (100 MHz1 CDCI3) δ 181.7, 138.6, 138.1 , 137.8, 136.5, 134.7, 130.8, 130.7, 129.4, 46.9, 46.3, 45.5, 21.0, 20.4, 17.7, 16.2; IR (cm"1): 2917, 1609, 1489, 1437, 1408, 1326, 1309, 1273, 1233, 1033; ESI LRMS: 585 (M+1 , 100); ESI HRMS: calcd for C35H44N4S2+Na 607.2905, found 607.2883.
Example 4 Synthesis of cyclic bis-thiourea ligands 1p and 1q:
. 2HCI 70 H7N' SNH ClCH2COOEt /—*( NaOH Ar-NH2 Ar-NH O- Ar-NH OH NaCO3 EDCI/HOBt
O BH3 SMe2 phosgene /"--|\| ./" N' N N-Λ Thio H H NH HN' reflux < H H > NH HN Na2CO3 N^s S^"N Ar' λr Ar Ar Ar Ar 1p: Ar=Mesιtyl 1q: Ar=2,5-Bul2-Ph
Preparation of 1p and 1q: Borane-dimethylsulfide (2M in THF) (3.6ml 7.2mmol, δequiv.) was added to a solution of diamide (0.9 mmol) in THF (20ml) at 0 °C. Then the solution was refluxed overnight. After cooling to room temperature, methanol was added very slowly to destroy the excess borane. The solvent was removed. Methanol (10 ml) was added and removed again under reduced pressure. The resulting tetraamine was directly used in the next step. To a stirred mixture of tetraamine obtained above and Na2CO3 (6 equiv.) in dry THF was added a dilute solution of thiophosgene in THF. Then the mixture was stirred at room temperature overnight. The pure cyclic bis- thiourea was obtained as a white solid through flash chromatography and recrystalyzation from ethanol.
1p: White solid, 45% yield for two steps; m.p >230 0C; 1H NMR (400 MHz, CDCI3) δ 8.20 (s, 1 H), 7.51-7.44 (m, 3H), 6.97 (s, 4H), 4.29 (t, J = 8.4Hz, 4H), 3.91 (t, J = 8.4 Hz, 4H), 2.31 (s, 6H), 2.28 (s, 12H); 13C NMR (100 MHz1 CDCI3) δ 180.7, 141.0, 138.3, 136.3, 134.7, 129.4, 128.6, 121.1 , 120.2, 49.3, 47.2, 21.0, 17.8; IR (cm"1): 2917, 1604, 1489, 1421 , 1306, 1277, 1076; ESI LRMS: 515 (M+1 , 100); ESI HRMS: calcd for C30H34N4O4S2+H 515.2303, found 515.2294.
1q: White solid, 41 % yield for two steps; m.p >230°C; 1HNMR (400 MHz, CDCI3) δ 8.24-8.22 (m, 1 H), 7.53-7.43 (m, 3H), 7.38 (d, J = 2.0 Hz, 2H), 7.35 (d, J = 2.0 Hz, 2H), 7.11 (s, 2H), 4.29-4.18 (m, 4H), 4.13-4.07 (m, 2H), 4.01- 3.93 (m, 2H), 1.48 (s, 18H), 1.34 (s, 18H); 13C NMR (100MHz, CDCI3) δ 184.1 , 150.5, 145.0, 141.2, 139.6, 128.8, 128.7, 128.2, 127.5, 125.5, 121.8, 121.6, 121.2, 52.6, 49.4, 35.4, 34.3, 31.9, 31.2; IR (cm"1): 2960, 1604, 1559, 1475, 1414, 1297, 1084; ESI LRMS: 655 (M+1 , 37), 639 (100); ESI HRMS: calcd for C40H54N4S2+H 655.3868, found 655.3864
Example 5 General procedure for Heck reaction of aryl iodides and olefins Pd(dba)2/thiourea ^ R ArI + =/ TEA, DMF Ar" 100 0C Pd(dba)2 (1.5 mg, 0. 0025 mmol) and thiourea (4 equiv) were stirred in DMF (0.5 mL) for 0.5 h at rt. Iodobenzene (0.28 mL, 2.5 mmol, substrate/catalyst ratio = 1000:1 ) and methyl acrylate (0.27 mL, 3.0 mmol) and TEA (0.42 mL, 3.0 mmol) were then added. The flask was sealed with rubber septa and heated at 100°C (the same result was obtained when the reaction was conducted with a condenser in open air). After the indicated time, the solution was diluted with ethyl acetate (20 mL) and washed with water and brine. Ethyl acetate was removed under vacuum and nitrobenzene (0.128 mL) was added as an internal standard. The yield of coupling product was determined by 1H NMR (400 MHz or 300 MHz) analysis, by comparing the peak intensities of the α/β-H of the product and the ortho-H of nitrobenzene (internal standard).
χCOOMe p/ 1H NMR (300 MHz, CDCI3) δ 7.67-7.63 (m, 2H), 7.54 (d, J = 4.1 Hz, 2H), 7.38 (d, J = 3.3 Hz, 1 H), 7.10 (t, J = 6.5 Hz, 1 H), 6.44 (d, J = 16.1 Hz, 1 H), 3.81 (s, 3H). To determine the reaction yield, the product peak at 6.44 ppm was selected for comparison with that of the ortho-\λ (at 8.20 ppm) of nitrobenzene (internal standard). COOBu-n prf 1H NMR (400 MHz, CDCI3) δ 7.73 (d, J = 16.0 Hz, 1 H), 7.52-7.57 (m, 2H), 7.40-7.45 (m, 3H), 6.49 (d, J = 16.0 Hz, 1 H), 4.26 (t, J = 6.9 Hz, 2H), 1.71 -1.78 (m, 2H), 1.54-1 .45 (m, 2H), 1 .00 (t, J = 7.4 Hz, 3H). ph^=^∞oBu-t 1 H NMR (300 MHz Q0Qi3) δ j 73 (di j _ 16 Q HZi 1 H)] 7 53.7 57
(m, 2H), 7.40-7.45 (m, 3H), 6.49 (d, J = 16.0 Hz, 1 H), 1.34 (s, 9H). Ph prf 1H NMR (300 MHz, CDCI3) δ 7.53 (d, J = 7.2 Hz, 4H), 7.38 (dd, J = 7.1 , 1.5 Hz, 4H), 7.28 (d, J = 7.2 Hz, 2H), 7.13 (s, 2H).
Rf 1H NMR (300 MHz, CDCI3) δ 7.55 (d, J = 9.4 Hz, 2H), 7.52 (d, J = 16.0 Hz, 1 H), 7.40 (t, J = 3.5 Hz, 3H), 6.72 (d, J = 16.0 Hz, 1 H), 2.39 (s, 3H). . — . ^COOBu-n CI~V./ ^ 1H NMR (300 MHz, CDCI3) δ 7.63 (d, J = 16.2 Hz, 1 H), 7.43 (d, J = 6.2 Hz, 2H), 7.35 (d, J = 6.2 Hz, 2H), 6.40 (d, J = 16.2 Hz, 1 H), 4.26 (t, J = 6.9 Hz, 2H), 1.78 1.71 (m, 2H)1 1.54 1.45 (m, 2H), 1.00 (t, J = 7.4 Hz, 3H). . — . ^COOBu-n H>COΛJ^~^ 1|H NMR ^400 MHZi Q0Ql3) g 7 Q8 (^ J _ 16 0 HZ] 1 H)_
7.51 (d, J = 8.9 Hz, 2H), 6.94 (d, J = 8.9 Hz, 2H), 6.36 (d, J = 16.0 Hz, 1 H), 4.25 (t, J = 6.8 Hz, 2H), 3.87 (s, 3H), 1.76-1.70 (m, 2H), 1.52-1.46 (m, 2H), 1.02 (t, J = 7.5 Hz, 3H). _COOBU-n H2N→l/ 1H NMR (400 MHz, CDCI3) δ 7.70 (d, J = 8.4 Hz, 2H), 7.56 (d, J = 15.7 Hz, 1 H), 6.62 (d, J = 8.4 Hz, 2H), 6.51 (d, J = 15.7 Hz, 1 H), 6.17 (s, 2H)1 4.26 (t, J = 6.9 Hz, 2H), 1.78 1.77 (m, 2H), 1.54-1.45 (m, 2H), 1.00 (t, J = 7.4 Hz, 3H). COOMe nT^ 1H NMR (300 MHz, CDCI3) δ 7.55 (d, J = 6.9 Hz, 2H), 7.40-7.19 (m, 4H), 3.82 (s, 3H), 2.13 (s, 3H). \ ^COOMe Rf 1H NMR (300 MHz, CDCI3) δ 7.53-7.45 (m, 3H), 7.37-7.35 (m, 2H), 6.13 (q, J = 1.2 Hz, 1 H), 3.75 (s, 3H), 2.58 (d, J = 1.3 Hz, 3H).
Example 6 General procedure for Heck reaction of aryl bromides and olefins Pd(dba)2-1g R R ArBr + =/ NaOAc, NMP Ar" 13O 0C Pd(dba)2 (1.5 mg, 0. 0025 mmol) and thiourea 1g (3.4 mg, 0.01 mmol) were stirred in NMP (0.5 ml_) for 0.5 h at rt. Aryl bromide (2.5 mmol, S/C = 1000), olefin (3.8 mmol) and sodium acetate 330 mg (3.8 mmol) were added in turn. Then the flask was sealed with a septa and heated at 130°C. After indicated time, the solution was dilute with ethyl acetate (20 ml_) and washed with water and brine. Ethyl acetate was removed under vacuum and nitrobenzene (0.128 ml_) was added as internal standard. The yield of coupling product was determined by 1H NMR (400 MHz or 300 MHz) analysis, by comparing the peak intensities of the α/β-H of the product and the ortho-H of nitrobenzene (internal standard).
/==v ^COOMe OHCΛ_# ^ 1H NMR (300 MHz, CDCI3) δ 9.99 (s, 1 H), 7.87 (d, J = 8.1 Hz, 2H), 7.70-7.62 (m, 3H), 6.52 (d, J = 15.9 Hz, 1 H), 3.79 (s, 3H). ,COOMe H3COC-^r iH NMR (300 MHZ[ CDCI3) δ 7.80-7.75 (m, 3H), 7.42 (d, J = 6.8 Hz, 2H), 6.34 (d, J = 16.1 Hz, 1 H), 3.63 (s, 3H), 2.42 (s, 3H). H3coc-\_/^ 1H NMR (400 MHz, CDCI3) δ 7.53-7.45 (m, 4H), 7.36-7.32 (m, 4H), 7.28-7.26 (m, 2H), 7.17 (d, J = 12.3 Hz, 1 H), 7.07 (d, J = 12.3 Hz, 1 H), 2.55 (s, 3H). phoc-0^^ iH NMR (300 MHZi CDCy δ 7 85_7 32 (mi 15H)1 6.24 (d, J = 16.2 Hz, 1 H).
\Jf 1H NMR (300 MHz, CDCI3) δ 8.70 (d, J = 1.3 Hz, 1 H), 8.45 (d, J = 3.5 Hz, 1 H), 7.52 (d, J = 9.0 Hz, 1 H), 7.36-7.33 (m, 2H), 7.30-7.25 (m, 4H), 7.10 (d, J = 16.2 Hz, 1 H), 7.00 (d, J = 16.2 Hz, 1 H).
Example 7 General procedure for Heck reaction of deactivated aryl bromides and activated chlorides with olefins Pd(dba)2-1g R R ArX + =/ NaOAc, TBAB Ar' 135 0C Pd(dba)2 (1.5 mg, 0. 0025 mmol), thiourea 1g (3.4mg, 0.01 mmol) and sodium acetate (33 mg, 3.8 mmol) were stirred in molten TBAB (0.5 g) for 10 min at 100°C. Aryl halide (0.25 mmol, S/C=100) and olefin (0.38 mmol) were added in turn. Then the flask was sealed with a septa and heated at 1350C. After indicated time, the solution was dilute with ethyl acetate (20 ml_) and washed with water and brine. Ethyl acetate was removed under vacuum and nitrobenzene (0.0128 ml_) was added as internal standard. The yield of coupling product was determined by 1H NMR (400 MHz or 300 MHz) analysis, by comparing the peak intensities of the α/β-H of the product and the ortho-H of nitrobenzene (internal standard).
H3∞-O^^ 1H NMR (400 MHz, CDCI3) δ 7.64-7.52 (m, 4H), 7.45-7.40 (m, 3H), 7.33 (d, J = 12.1 Hz, 1 H), 7.10 (d, J = 12.1 Hz, 1 H), 6.98 (d, J = 8.2 Hz, 2H), 3.88 (s, 3H).
^No2 1H NMR (400 MHz, CDCI3) δ 7.93 (d, J = 7.0 Hz, 1 H), 7.74 (d, J = 7.0 Hz, 1 H), 7.60-7.51 (m, 5H), 7.39-7.30 (m, 3H), 7.07 (d, J = 16.1 Hz, 1 H). ,COOBu-n -No2 1H NMR (400 MHz, CDCI3) δ 8.13 (d, J = 17.3 Hz, 1 H), 8.05 (d, J = 7.8 Hz, 1 H), 7.84 (d, J = 6.8 Hz, 1 H), 7.27-7.24 (m, 2H), 6.36 (d, J = 17.3 Hz, 1 H), 4.22 (t, J = 5.0 Hz, 2H), 1.71-1.67 (m, 2H), 1.32-1.28 (m, 2H), 0.96 (t, J = 6.8 Hz, 3H). , — ■ ^COOBU-n ww\J^ 1H NMR (300 MHz, CDCI3) 6 7.62 (d, J = 15.6 Hz, 1 H), 7.41 (d, J = 7.1 Hz, 2H), 6.66 (d, J = 7.1 Hz, 2H), 6.22 (d, J = 15.6 Hz, 1 H), 4.18 (t, J = 6.7 Hz, 2H), 3.00 (s, 6H), 1.71-1.66 (m, 2H), 1.47-1.40 (m, 2H), 0.96 (t, J = 8.2 Hz, 3H).
Example 8 General procedure for the Suzuki reaction of Aryl halides with boric
acids
Pd(dba)2/1q Ar1Br + Ar2B(OH)2 " Ar1- Ar2 K2CO3, NMP/H2O
Aryliodide or bromide (0.5 mmol), arylboric acid (0.6 mmol), K2CO3 (1.0
mmol), bis-thiourea-Pd(dba)2 1q complex in NMP (2.5χ10"3 M solution) and
NMP/H2O (0.75 ml/0.25 ml) were added to a flask under aerobic conditions.
The flask was sealed with rubber septa and heated at the desired temperature.
The reaction mixture was diluted with ethyl acetate, washed with brine, and
dried over Na2SO4. The solvent was removed and the residue was purified by
a flash chromatography on silica gel to give the product.
S\ // <Λ />— -O UCOHH-3, V_y VJ" 1H NMR (200 MHz, CDCI3) δ 7.56-7.50 (m, 4H), 7.44-
7.37 (m, 2H), 7.32-7.25 (m, 1 H), 6.97 (d, J = 8.7 Hz, 2H), 3.84 (s, 3H). \ /n\ /rCHO 1H NMR (200 MHz, CDCI3) δ 10.05 (s, 1 H), 7.97-7.93 (m, 2H), 7.77-7.72 (m, 2H), 7.66-7.61 (m, 2H), 7.52-7.39 (m, 3H). \\ \ /-coocH3 n 1HNMR (200 MHz, CDCI3) δ 8.10 (d, J = 8.2 Hz, 2H), 7.68-7.60 (m, 4H), 7.49-7.36 (m, 3H), 3.93 (s, 3H). \ /M\ / N°2 1H NMR (200 MHz, CDCI3) δ 8.45 (m, 1 H), 8.21 -8.17 (m, 1 H), 7.93-7.89 (m, 1 H), 7.64-7.56 (m, 3H), 7.50-7.42 (m, 3H). F-,C r F33C NO 2 1H NMR (400 MHz, CDCI3) δ 8.50-8.49 (m, 1 H), 8.34 (d, J = 8.0 Hz, 1 H), 8.06 (s, 2H), 7.98-7.95 (m, 2H), 7.73 (t, J = 8.0 Hz, 1 H). F NO2 iH NMR (200 MHz, CDCI3) δ 8.41-8.40 (m, 1 H), 8.28-8.23 (m, 1 H), 7.89-7.84 (m, 1 H), 7.68-7.60 (m, 1 H), 7.16-7.12 (m, 2H), 6.92-6.83 (m, 1 H). OCHq 1HNMR (400MHz, CDCI3) δ 7.49 (d, J = 8.8 Hz, 2H), 7.09-7.03 (m, 2H), 6.98 (d, J = 8.8 Hz, 2H), 6.76-6.70 (m, 1 H), 3.86 (s, 3H). \_JT~\-/~N°2 1H NMR (200 MHz, CDCI3) δ 8.29 (d, J = 9.0 Hz, 2H), 7.73 (d, J = 9.0 Hz, 2H), 7.60 (m, 2H), 7.52-7.40 (m, 3H). ' HNMR (400MHz, CDCI3) δ 7.36-7.33 (m, 10H), 5.47 (s, 2H). NOTES
The following notes correspond to the superscripts contained in the application. Each of the references listed below are incorporated by reference herein.
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