STEREOSELECTIVE SYNTHESIS OF 17-oc-AND 17-β-ARYL STEROIDAL COMPOUNDS

Description

GOVERNMENTAL SUPPORT The present invention was made with governmental support pursuant to USPHS grant 5F1GM070414 from the National Institutes of Health. The government has certain rights in the invention.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from provisional application No. 60/050,434, filed May 05, 2008, whose disclosures are incorporated herein by reference .

TECHNICAL FIELD

The present invention relates generally to synthesis of 17-arylsubstituted steroidal compounds, and particularly to a 17-arylsubstituted steroidal natural product called (+) cortistatin A, 17-arylsubstituted synthetic analogues of that natural product. More particularly, the invention contemplates new methods of preparing 17-α— .and 17- β-aryl steroid compounds and particularly analogues of (+) cortistatin A and related compounds.

BACKGROUND ART

Natural products have always been a successful pool of molecules from which the pharmaceutical industry can find novel medicinal agents. [Baker et al . , Nat. Prod. Rep. 2007,

24:1225-1244] Steroids, in particular, continue to be the subject of medicinal investigations for two reasons: they are "privileged" [Burger' s Medicinal Chemistry and Drug Discovery Vol. 5 (Ed. Wolff), John Wiley & Sons, Inc., 1997, 281-376] pharmacophores and their scrutiny for over half a century has resulted in a vast body of knowledge regarding their reactivity. [Biellmann, Chem. Rev. 2003, 103:2019 - 2033]

The steroid ring system contains four fused rings that are named the A-, B-, C- and D-rings from left to right in the direction that those rings are usually portrayed as is shown below in Formula I,

along with the ring position numbers. The usual stereochemistry at the positions of ring fusion is trans, making the molecules relatively planar, although cis fusions occur and can be made. Unsaturated bonds within one or more rings also occur at bridge head positions . Steroid molecules also usually have methyl or other alkyl groups bonded to the carbon atoms at the 10 and 13 positions and those methyl or alkyl groups typically extend above the plane of the molecule. See, for example, Smith et al. U.S. Patent No. 3,850,911.

Steroidal compounds containing an aryl substituent at the 17 -position of the steroidal ring system (in the D-ring) have been found to possess

biological activity in a number of environments. For example, Jiang et al., Bioorg. Med. Chem. Lett. 2007 17:1471 - 1474 reported syntheses of 17-aryl-ll- phenylphosphorous-containing steroids that showed activity as potential agents to treat type II diabetes. Boivin et al . , J. Med. Chem., 2000 43(23) .-4465-4478 reported synthesis of 17-aryl estradiol compounds as inhibitors of steroid sulfatase. Peters et al . , J. Med. Chem. 2002 32(7) .-1642-1652 reported preparation of 17-aryl-17- desoxy estrogen analogs as potential postcoital antifertility agents. Venepalli et al . , J. Med. Chem. 2002 35 (2) .-374-378 reported the synthesis of a group of benzimidazolefused steroids {androstano [3 , 2- b]pyrimido [1, 2-a] benzimidazoles} including a 17-aryl substituted compound said to be competitive antagonists at the substance P receptor. European patent application EP 0 590 271 A2 reports the preparation and use of 17-aryl and 17-heterocyclyl- 5α, 14β-androstane, androstene, and androstadiene derivatives said to be useful in the treatment of cardiovascular disorders such as heart failure and hypertension. European Patent EP 0 551952 Bl teaches cardioactive 17 -phenyl and substituted phenyl steroidal compounds that are cardioactive .

Recently, Kobayashi and his collaborators elucidated the structures of cortistatins A-L [see Scheme A, below, for the structure of cortistatin A

Scheme A

• 1.8 nM inhibition of HUVECs

•Most potent member of Cortistatin family 2 steps

3: cortistatinone

^■ gram-quantities prepared

H ? 12-steps from prednisone

(I)] from the sponge Corticium simplex. [a) Aoki et al., J. Am. Chem. Soc. 2006, 228:3148-3149; b) Watanabe et al . , Tetrahedron 2007, 53:4074-4079; c) Aoki et al., Tetrahedron Lett. 2007, 45:4485-4488; d) Aoki et al., Bioorg. Med. Chem. 2007, 25:6758-6762; e) Sato et al . , Biosci. Biotechnol. Biochem. 2008, 72:2992-2997] These marine derived steroidal alkaloids exhibit potent anti-angiogenic activity against HUVECs (human umbilical vein endothelial cells) by a unique mechanism. [a) Aoki et al . , J. Am. Chem. Soc. 2006, 228:3148-3149; b) Watanabe et al., Tetrahedron 2007, 63:4074-4079; c) Aoki et al . , Tetrahedron Lett. 2007, 48:4485-4488; d) Aoki et al . , Bioorg. Med. Chem. 2007, 25:6758-6762; e) Sato et

al., Biosci. Biotechnol. Biochem. 2008, 72:2992-2997] Although the Kobayashi group has already delineated a preliminary SAR picture of the family (see Scheme A) , their scarce natural supply renders chemical synthesis as the only means to decipher their medicinal potential. Particularly intriguing is the impact of the isoquinoline moiety on biological activity since its absence significantly lowers activity.

The invention described hereinafter illustrates the dramatic influence of D-ring stereochemistry on biological activity with the synthesis of 17-epi-cortistatin A (4) . Specifically, it is found that the C- 17 stereochemistry can be removed all together as δ ¹⁶ -cortistatin A (2) retains much of the potency of 1. This line of chemical inquiry has also led to the first useful method for the stereocontrolled preparation of other α-aryl- substituted D-ring steroids.

Several approaches have been reported for the preparation of the core structure of cortistatins . [a) Dai et al . , Heterocycles 2009, 77:157-161; b) Simmons et al . , Angew. Chem. Int. Ed. 2008, 47:6650-6653; c) Yamashita et al . , Org. Lett. 2008, 10:3413-3415; d) Craft et al . , Tetrahedron Lett. 2008, 49:5931-5934; e) Dai et al . , Danishefsky, Tetrahedron Lett. 2008, 49:6610-6612; f) Dai et al . , Tetrahedron Lett. 2008, 49:6613-6616; g) Kotoku et al., Tetrahedron Lett. 2008, 49:7078-7081; h) Kϋrti et al., Org. Lett. 2008, 10:5247-5250; i) Yamashita et al., Tetrahedron Lett. 2009 in press; j) Craft et al., Tetrahedron Lett. 2008 49:5931-5934; k) review, see: Nishing et al . , Angew. Chem. Int. Ed. 2008, 47:9389-9391] Two elegant total syntheses of the

most potent member of this natural product class, cortistatin A (1) , have appeared from the Nicolaou- Chen [Nicolaou et al . , Angew. Chem. Int. Ed. 2008, 47:7310-7313] and Shair groups [Lee et al . , J. Am. Chem. Soc. 2008, 130:16864-16866] .

Our own synthetic plan [Shenvi et al . , J. Am. Chem. Soc. 2008, 130, 7241 - 7243] was profoundly- affected by the strategic choice to use prednisone - a synthetic corticosteroid produced annually on multi-ton scale by microbial oxidations of naturally occurring steroids - as a starting material. Aside from economical considerations, this choice was made with the knowledge that semi-synthetic approaches have enjoyed decades of success in the pharmaceutical industry. Thus, a twelve- step sequence was utilized from this starting point to arrive at cortistatinone (3) in gram quantities. [Shenvi et al . , J. Am. Chem. Soc. 2008, 130, 7241 - 7243] The synthesis concluded with a highly chemo- and stereoselective Raney nickel (Ra-Ni) mediated hydrogenation of δ ¹⁶ -cortistatin A (2) . To evaluate the importance of a β-oriented isoquinoline moiety, an estrone-derived model (5, Scheme 1, below) was employed as a test bed for a strategy that would deliver both epimers from a common intermediate .

Scheme 1

6a [x-ray] 8a [x-ray]

By analogy to the synthesis of 2, estrone model 5 was converted to the D-ring styrene 6a as depicted in Scheme 1. Regardless of the reducing conditions, the only observed product was the expected β-aryl substituted product 7a. Ra-Ni mediated reduction led to a 97% isolated yield of 7a. This is not surprising given the fact that an overwhelming majority of nucleophilic, electrophilic, and radical substitution reactions at C- 17 occur from the a-face. [Fieser and Fieser, Steroids, Reinhold: New York, 1959] Attention was therefore turned to an alternative approach that began with tertiary alcohol 8a, derived from addition of PhLi to 5. Based on preliminary evidence gathered in-house, [C. A. Guerrero Ph. D. Thesis, The Scripps Research

Institute, 2008; b) R. A. Shenvi Ph. D. Thesis, The Scripps Research Institute, 2008] and a report that Ra-Ni reductions of benzylic alcohols occurred with retention of configuration, [a) Mitsui et al . , Bull. Chem. Soc. Jpn . 1961, 34:774-778; b) Krafft et al . , J. Org. Chem. 1988, 53:432-434] alcohol 8a was subjected to Ra-Ni in toluene at reflux. To our delight, a diastereomeric pair of compounds was isolated in a 6.6:1 ratio, the major isomer of which bore the desired α-stereochemistry . The structures of Compounds 6a-9a were all verified by X-ray crystallography.

The generality of this reagent system to the D-ring of a steroidal ring system, a synthesis of 17-epi-cortistatin A, mechanistic analysis of these synthetic processes, and biological evaluation of cortistatin and other steroidal analogs are presented as part of the disclosure below.

BRIEF SUMMARY OF THE INVENTION The present invention contemplates synthesis of a diastereo excess of one or the other of a 17-arylsubstituted steroidal compound, and particularly the 17-arylsubstituted steroidal natural product called (+) cortistatin A. 17-α-Aryl- substituted and 17-β-aryl-substituted synthetic analogues of (+) cortistatin A are disclosed as are several illustrative 17 -α-, and 17-β-aryl steroid compounds .

Thus, a process for forming one or the other of a 17-α- or 17-β-aryl steroidal compound in diastereo excess is contemplated. That process

comprises the steps of reacting a 17-keto steroid whose D-ring has the structure shown below

with an aromatic ring moiety to form a compound whose D-ring has structure A or B, below,

where Ar is an aromatic ring substituent. A compound having a structure A D-ring is reacted with Raney nickel under reducing conditions to form a compound whose D-ring has the structure C, below, in which the

C diastereo ratio of the aromatic ring substituent being in the β-conformation to α-conformation is at least about 3:1, Alternatively, a compound having a structure B D-ring is reacted with Raney nickel under dehydration conditions to form a compound whose D-ring has the structure C

in which the diastereo ratio of the aromatic ring substituent being in the α-conformation to β-conformation is at least about 3:1.

It is noted that the steroidal ring system is shown above in abbreviated form by just illustrating the D- ring with the 13 -position methyl group, a trans-fused C- and D-ring junction, and wavy lines across bonds to the C-ring and the remainder of the molecule following usually used abbreviation terminology of organic chemistry. The wavy line in structure C is used to indicate that both α- and β-configurations are contemplated, again, following usual terminology used in organic chemistry.

In one preferred embodiment, the 17-keto steroid is reacted to form a vinyl sulfonate ester that is reacted with an aryl boronic acid in the presence of a palladium catalyst to form a compound whose D-ring has structure A. In other preferred embodiment, the 17-keto steroid is reacted to form a 17-hydrazone that is reacted with iodine to form a

δ ¹⁶ -17-iodo-steroid, that is reacted an aryl tri-Cχ- Cg-alkyltin in the presence of a palladium catalyst to form a compound whose D-ring has structure A. In a further preferred embodiment, the 17-keto steroid is reacted with an alkali metal aryl compound to form a compound whose D-ring has structure B. It is also

preferred that the 17-arylsteroid so formed be recovered or otherwise isolated.

The present invention has several benefits and advantages .

A benefit of the invention is that preparation of a single intermediate, a 17-keto steroid, one can either a 17-a-aryl or a 17-b-aryl compound in large diastereoexcess over the other isomer (epimer) .

An advantage of the invention is that 17-aryl substituents that are themselves substituted with either electron donating or electron withdrawing substituents can be readily prepared.

A further benefit of the invention is that 17-aryl substituents containing hetero atoms in the aromatic ring can be prepared.

A further advantage of the invention is that its contemplated reactions are carried out in common laboratory apparatus and do not require high temperatures or pressures.

Still further benefits and advantages of the invention will be apparent to the worker of ordinary skill from the discussion that follows.

Definitions

Epimer-Following the usual chemical usage, an epimers are diastereomers that differ in configuration of only one stereogenic center. Diastereomers are stereoisomers that are non- superposable, non-mirror images of one another, unlike enantiomers that are non-superposable mirror images of one another

Steroid-As noted earlier, a steroid is usually deemed to have the four fused ring structure illustrated in Formula I. Cortistatin A and many other compounds contain ring structures that contain one or more additional methylene groups in a ring, or one or more fewer methylenes in a ring. Steroid compounds containing more than the usual number of ring methylenes are referred to as by the prefix homo-, and those containing two added methylene groups by dihomo- . Ring contraction by loss of an unsubstituted methylene group is indicated by the prefix nor-, with loss of two methylene groups, being indicated by the prefix dinor- . Specific nomenclature rules for use of these terms in steroidal nomenclature are well known by skilled workers . Cortistatin A and its related compounds are technically homo- steroids, but are referred to in the art as "steroids". See for example, Dai et al . , Tetrahedron Lett. 2008, 49:6610-6612; Sato et al . , Biosci. Biotechnol. Biochem. 2008, 12 (11) .-2992-2008 ; Kotoku et al., Tetrahedron Lett. 2008, 49:7078-7081; Kύrti et al., Org. Lett. 2008, 10 (22) .-5247-5250 ; Simmons et al . , Angew. Chem. Int. Ed. 2008, 47:6650- 6653; and Dai et al . , Heterocycles 2009, 77(1) :151- 161. The word "steroid" is used herein to include cortistatin A and similar homo-, dihomo- , nor- and dinor- steroids, as well as compounds having the usual four fused rings of a steroid nucleus along with one or more further rings such as the androstano [3 , 2-b] pyrimido [1, 2 -a] benzimidazoles disclosed in Venepalli et al . , J. Med. Chem. 2002 35 (2) .-374-378 or the 17-aryl-ll-phenylphosphorous- containing steroids reported in Jiang et al . , Bioorg. Med. Chem. Lett. 2007 17:1471 - 1474.

DETAILED DESCRIPTION OF THE INVENTION The present invention contemplates a process for forming one or the other of a 17 -α- or 17-β-aryl steroidal compound in diastereo excess. Thus, in accordance with a contemplated process, one 17-aryl epimer (α- or β-) is formed in excess over the other 17-aryl epimer (β- or α- , respectively) .

A contemplated process comprises the steps of reacting a 17-keto steroid whose D-ring has the structure shown below

with an aromatic ring moiety to form a compound whose D-ring has structure A or B, below,

where Ar is an aromatic ring substituent. A compound having a structure A D-ring is reacted with Raney nickel under reducing conditions to form a compound whose D-ring has the structure C, below, in which the

diastereo ratio of the aromatic ring substituent in the β-conformation to α-conformation is at least about 3:1. Put differently, the ratio of 17-β epimer to 17-α epimer is at least about 3:1. Alternatively, a compound having a structure B D-ring is reacted with Raney nickel under dehydration conditions to form a compound whose D-ring has the structure C

in which the diastereo ratio of the aromatic ring substituent in the α-conformation to β-conformation is at least about 3:1. Put differently again, the ratio of 17-α epimer to 17-β epimer is at least about 3:1.

In preferred practice for preparation of an epimeric excess of a 17-β-aryl steroid, a 17-keto steroid is reacted to form a compound whose D-ring has structure A. Several techniques can be used for such preparations.

In one embodiment , for example, a vinyl sulfonate such as a vinyl mesylate, besylate or vinyl triflate is prepared. A vinyl triflate is readily prepared as discussed in Liu et al . , J. Org. Chem.

1996, 61:6693-6699, and was used herein. The vinyl triflate or other sulfonate so formed is reacted with an aryl boronic acid [ArB (OH) 2] in the presence of a palladium catalyst in a Suzuki coupling to form the steroid of Formula A.

A compound whose D-ring has a structure of Formula A can also be prepared by a Stille coupling reaction [Milstein et al . , J. Am. Chem. Soc. 1978,

200:3636-3638] from the corresponding δ ¹⁶ -17-iodo- steroid as discussed in Shenvi et al., J. Am. Chem. Soc. 2008, 130:7241-7243. Thus, illustratively, the 17-keto steroid is reacted to form a 17-hydrazone that is reacted with iodine to form a δ ¹ ^-17-iodo- steroid. The δ^^- 17 -iodo- steroid so formed is reacted an aryl tri-Ci-Cg-alkyltin such as phenyltrimethyltin in the presence of a palladium catalyst to form a steroid compound whose D-ring has structure A.

In a preferred preparation of an epimeric excess of a 17-α-aryl steroid, the 17-keto steroid is reacted with an alkali metal aryl compound to form a compound whose D-ring has structure B. As is illustrated hereinafter in General Procedure A, an aryl halide such as an aryl chloride, bromide or iodide is reacted with an alkali metal reagent such as butyl lithium or the like to form an aryl alkali metal compound that is then reacted with a 17-keto steroid to form the corresponding 17 -aryl -17- hydroxysteroid shown in structure B, above.

It is to be understood that the above reactions are carried out in an appropriate solvent and at an appropriate temperature. Those reactions have analogous literature precedents.

A compound having a structure A D-ring is reacted with Raney nickel under reducing conditions to form a compound whose D-ring has the structure C. The product of that reduction has an excess of the 17-β-aryl steroid over the corresponding 17-α-aryl steroid. The two epimers so formed are present in the product in a ratio of at least about 3:1 β:α. More usually, the β:α ratio is about 20:1 or greater. The yield of 17-aryl steroid in this reduction is also typically about 60 to 90%, and often greater than 90%.

Catalytic reductions using Raney nickel are well known in the art and are illustratively carried out in a mixture of iso-propyl alcohol (i-PrOH) /toluene at a volume ratio of about 7:1 to about 12:1, respectively, and more preferably at a ratio of about 9:1, as is shown in General Procedure D hereinafter. Other useful solvents illustratively include 2 , 2 , 2-trifluoroethanol, hexafluoro-2- propanol, n-butanol, ethanol, methanol, o-, m- and p- xylene, aqueous sodium and potassium hydroxide, benzene, aqueous hydrochloric and sulfuric acids, trifluoroacetic acid, acetone and THF, and mixtures thereof . The reduction is preferably carried out at a temperature of about 50° to about 70° C.

A compound of Formula B is converted to form a 17-α-aryl steroid using a deoxygenation reaction that is also catalyzed by Raney nickel. This reaction is illustrated in General Reaction E, hereinafter. The diastereo ratio of α:β aryl steroids so formed is at least 3:1, and is more usually about 4:1 to about 20:1 or more. Product yields in the

deoxygenation reaction are typically about 60 to almost 100 percent.

The reaction can be carried out at temperatures from about ambient room temperature up to about 140° C, but is more preferably carried out at a temperature of about about 80° to about 110° C. Toluene is a preferred solvent for this reaction. However, other useful solvents illustratively include 2, 2, 2-trifluoroethanol, hexafluoro-2-propanol, n- butanol, ethanol, methanol, o- , m- and p-xylene, aqueous sodium and potassium hydroxide, benzene, aqueous hydrochloric and sulfuric acids, trifluoroacetic acid, acetone and THF, and mixtures thereof .

It is also preferred that a 17-aryl steroid so formed be recovered or otherwise isolated. Various methods of isolation and recovery are well known in the art and include thin and thick layer chromatography, column chromatography, high pressure liquid chromatography, distillation, crystallization and the like.

The skilled worker will appreciate that the above description has omitted a discussion of any other reactive moieties that may be bonded to or as part of a 17-keto steroid reactant or a 17-aryl steroid product. Such a skilled worker will know and understand which such groups should be protected from reaction during the before described transformations. For example, some of the transformations discussed hereinafter utilize an estrone as the 17-keto steroid. The 3-hydroxyl group of that compound is typically blocked with a removable blocking group such as a siIyI blocking group. A t-butyl - dimethylsilyl (TBS) group is utilized illustratively

herein, but other removable hydroxyl blocking groups such as trimethyl siIyI (TMS) , tetrahydropyranyl, 2- methoxyprop-2-yl, 1-ethoxyeth-l-yl, methoxymethyl, β-methoxyethoxymethyl, methylthiomethyl, t-butyl, t-amyl, trityl, 4-methoxytrityl, 4 , 4 ' -dimethoxy- trityl, 4, 4 ' ,4"-trimethoxytrityl, benzyl, allyl, trimethylsilyl, ( t-butyl) dimethylsilyl and 2,2,2- trichloroethoxycarbonyl groups, and the like can also be used. The species of hydroxy-protecting groups is also usually not critical so long as the derivatized hydroxyl group is stable to the conditions of subsequent reaction (s) and can be removed at the appropriate point without disrupting the remainder of the compound .

Further examples of hydroxy-protecting groups are described by C. B. Reese and E Haslam, Protective Groups in Organic Chemistry, J. G. W. McOmie, Ed., Plentun Press, New York 1973, Chapters 3 and 4, respectively, and T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2 ^nd ed. , John Wiley and Sons, New York, 1991, Chapters 2 and 3, whose disclosures are also incorporated by reference .

A steroid carboxyl group can be protected as an ester derivative. Examples of such carboxylic acid protecting groups include 4-nitrobenzyl, 4-methoxybenzyl, 3 , 4-dimethoxybenzyl, 2 , 4-dimethoxy- benzyl, 2, 4, 6-trimethoxybenzyl, 2 , 4 , 6- trimethyl- benzyl, pentamethyIbenzyl, 3 , 4 -methylene-dioxybenzyl, benzhydryl , 4,4' -methoxytrityl , 2 -phenylprop- 2 -yl , 4, 4 ',4' ' -trimethoxytrityl, trimethylsilyl, t-butyldimethylsilyl, 2,2, 2-trichloroethyl, β- (trimethylsilyl) ethyl, β- [di (n-butyl) - methylsilyl] ethyl, p-toluenesulfonylethyl,

4-nitrobenzyl-sulfonylethyl, allyl, cinnamyl, 1- (trimethylsilylmethyl) -prop-l-en-3-yl, and like moieties. The species of carboxy-protecting group employed is also usually not critical so long as the derivatized carboxylic acid is stable to the conditions of subsequent reactions and can be removed at the appropriate point without disrupting the remainder of the molecule .

Further examples of these groups are found in E. Haslam, Protective Groups in Organic Chemistry, J. G. W. McOmie Ed., Plenum Press, New York 1973, Chapter 5 and T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis 2 ^nd ed. , John Wiley and Sons, New York, 1991, Chapter 5, each of which is incorporated herein by reference.

Amine-substituted steroids can also be protected during a contemplated synthesis . Examples of useful amino-protecting groups include the formyl ("For") group, the trityl group (Trt) , the phthalimido group, the trichloroacetyl group, the chloroacetyl, bromoacetyl, and iodoacetyl groups. Urethane blocking groups, such as t-butoxy-carbonyl ("Boc") , 2- (4-biphenylyl) propyl (2) -oxycarbonyl ( "Bpoc " ) , 2 -phenylpropyl ( 2 ) oxycarbonyl ( " Poc " ) , 2- (4-xenyl) -isopropoxycarbonyl, 1, 1-diphenylethyl (1) - oxycarbonyl , 1,1-diphenylpropy1 ( 1 ) oxycarbonyl , 2- (3 , 5-dimethoxyphenyl) propyl (2) oxycarbonyl ("Ddz"), 2- (p- 5 -toluyl) propyl- (2) oxycarbonyl, eyeIo- pentanyloxycarbonyl , 1-methylcyclopentanyl- oxycarbonyl, cyclohexanyloxycarbonyl, 1-methyl- cyclohexanyloxycarbonyl, 2-methylcyclohexanyl- oxycarbonyl, 2- (4-toluylsulfonyl) ethoxycarbonyl, 2- (methylsulfonyl) ethoxycarbonyl, 2- (triphenyl- phosphino) ethoxycarbonyl, 9-fluoroenylmethoxycarbonyl

("Fmoc") , 2- (trimethylsilyl) ethoxycarbonyl, allyloxycarbonyl, 1- (trimethylsilylmethyl) prop-1- enyloxycarbonyl , 5 -benz - isoxalylmethoxycarbonyl , 4-acetoxybenzyloxycarbonyl, 2,2, 2-trichloro- ethoxycarbonyl , 2 -ethynyl (2) propoxycarbonyl , cyclopropylmethoxycarbonyl , isobornyloxycarbonyl , 1-piperidyloxycarbonyl , benzyloxycarbonyl ("Z"), 4 -phenylbenzyloxycarbonyl , 2-methylbenzyloxycarbonyl , α-2 ,4,5, -tetramethylbenzyloxycarbonyl ( "Tmz" ) , 4 -methoxybenzyl-oxycarbonyl , 4 -fluorobenzyloxy- carbonyl, 4 -chloro-benzyloxycarbonyl, 3-chloro- benzyloxycarbonyl , 2 -chlorobenzyloxycarbonyl , dichloro-benzyloxycarbonyl , 4 -bromobenzyloxycarbonyl , 3 -bromobenzyloxycarbonyl , 4 -nitrobenzyloxycarbonyl , 4 -cyanobenzyloxycarbonyl , 4 - (decyloxy) benzyloxycarbonyl, and the like, the benzoylmethylsulfonyl group, dithiasuccinoyl ("Dts ¹ ) group, the 2- (nitro) phenylsulfenyl group ("Nps ¹ ), the diphenyl- phosphine oxide group, and like amino-protecting groups. The species of amino-protecting group employed is also usually not critical so long as the derivatized amino group is stable to the conditions of the subsequent reactions and can be removed at the appropriate point without disrupting the remainder of the compound. Preferred amino-protecting groups are Boc and Fmoc .

Further examples of amino-protecting groups embraced to by the above term are well known in organic synthesis and the peptide art and are described by, for example T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2 ^nd ed. , John Wiley and Sons. New York., Chapter 7, 1991; M. Bodanzsky, Principles of Peptide Synthesis, 1 ^st and 2 ^nd revised eds . , Springer-Verlag, New York, 1984 and

1993; and Stewart and Young, Solid Phase Peptide Synthesis, 2 ^nd ed. , Pierce Chemical Co, Rockford. IL 1984. The term "protected amino" refers to an amino group substituted with an amino-protecting group discussed above.

Illustrative examples of the contemplated reactions are shown in Table 1. As is seen, both pathways (6 to 7 and 8 to 9) are amenable to the incorporation of electron rich, neutral, and withdrawn arenes, as demonstrated by the successful p-tolyl, p-anisyl, and 3-pyridyl steroids.

Hydrogenation of δ ¹⁶ -17-arylsteroids 6 was carried out in 10% toluene in isopropanol with Ra-Ni at 6O ⁰ C for 2 hours, providing 7 with yields varying between 68 percent and 98 percent. The diastereoselectivity of this transformation is generally over 20:1 (17- β:17-α) .

Table 1

Isolated Yield (%) and Diastereoselectivity

9a (α): 98%, dr=6.6:1 9b (α): 88%, dr>20:1 9c (α): 68%, dr=4.2:1 7a (β): 97%, dr>20:1 7b (β): 98%, dr>20:1 7c (β): 93%, dr>20:1

9e (α): 71%, dr=4.3:1 9d (α): 72%, dr=13:1 7f (β, R = F): 93%, dr>20:1 7e (β): 68%, dr>20:1 7d (β): 72%, dr>20:1 7g (β, R = CF ₃ ): 96%, dr>20:1

Alternatively, deoxygenation of 17 -β-hydroxy- 17 -α- arylsteroids 8 was carried out in toluene with Ra-Ni at 110°C for 5 hours. Yields varied between 68% and 98% with moderate to good diastereoselectivities . Structural formulas for the 17-β-hydroxy-17-α- arylsteroids 8a-8g are shown below.

8e 8f

8g

To determine the source of hydrogen in the reductions, deuterium labelling experiments were carried out as shown in Scheme 2, below. For Ra-Ni mediated transfer hydrogenation, the reaction of 6a was conducted in deuterated isopropanol and toluene (toluene or toluene- d ₈ gave identical results) with D ₂ 0-washed Ra-Ni, affording 7a-d ₂ with deuterium incorporation at C-16 and C- 17. For Ra-Ni mediated deoxygenation, the reaction of 8a employed deuterated toluene with D ₂ 0-washed Ra-Ni. Surprisingly, 9a-cU was obtained as the major product in 96% yield. However, 7a and 9a exhibited identical aromatic deuterium substitution when subjected to the same reduction conditions as 8a, demonstrating that this aromatic deuteration is independent of the deoxygenation process.

Scheme 2

The dichotomy in observed stereochemical outcome between 7 and 9 seemingly excludes the intermediacy of free-radicals in deoxygenation (8—»9; radical deoxygenation produces β-stereochemistry at C- 17, vide supra) . The differential stereoselectivity between 6 and 8 can be rationalized based on the facial selectivity of chemo-adsorption to the metal surface as depicted in Scheme B, below.

Scheme B

Previous studies [Mitsui et al . , Bull. Chem. Soc. Jpn 1970, 43:2143-2152, and references cited therein] have demonstrated that a high degree of stereoselectivity can be incurred in Ra-Ni mediated reductions based on stereoselective adsorption. In the case of 6, adsorption likely occurs most favorably on the relatively flat α-face, away from the angular methyl group (C- 18) . Hydrogens and/or electrons are then transferred from the metal surface to the preferentially adsorbed face. [Mitsui et al . , Bull. Chem. Soc. Jpn 1970, 43:2143-2152, and references cited therein.] In the case of 8,

adsorption possibly takes place on the convex face, with interaction occurring between the surface and both the aromatic p-system and the benzylic hydroxyl, followed by hydrogen/deuterium delivery from the metal .

Finally, the mechanistic requirement of an aryl group at C- 17 during deoxygenation is supported by the fact that 17-β-hydroxy-17-α- (n-butyl) -estrone (10) was inert to deoxygenation using Ra-Ni.

10

In addition to submitting 10 to the reaction condition, a control experiment was carried out with an equimolar mixture of 10 and 8a premixed in the same reaction vessel and treated with Ra-Ni . Although 8a was completely deoxygenated, 10 was quantitatively recovered.

The utility of the present invention is aptly demonstrated by the synthesis of 11-epi- cortistatin (4) , as shown in Scheme 3, below. Thus,

Scheme 3

a. TMSimid. b. 7-lithioisoquinoline TMEDA

3: cortistatinone

protection of the diol motif in cortistatinone (3) with TMS-imidazole, followed by treatment with an excess of 7-lithioisoquinoline in a THF/TMEDA solvent mixture at -78 ⁰ C generated an alkanolisoquinoline that was deoxygenated with Ra-Ni to deliver 17 -epi- cortistatin A (4) in 16% yield over three steps.

This substance proved crucial in testing the substrate scope/specificity of cortistatin A' s biological target. The importance of this substrate is clear because the greatest modulation of biological activity in the naturally occurring cortistatins stems from structure variations of the C-17 substituent. [a) Aoki et al . , J. Am. Chem. Soc.

2006, 128:3148-3149; b) Watanabe et al . , Tetrahedron

2007, 53:4074-4079; c) Aoki et al . , Tetrahedron Lett. 2007, 48:4485-4488; d) Aoki et al . , Bioorg. Med.

Chem. 2007, 15:6758-6762; e) Sato et al . , Biosci. Biotechnol. Biochem. 2008, 72:2992-2997]

In an assay to determine activity against HUVECs (carried out by Pfizer, Inc.), synthetic cortistatin A exhibited an IC ₅₀ value of 2.43 nM, which is in good agreement with the reported value. [Aoki et al., J. Am. Chem. Soc. 2006, 128:3148-3149] Remarkably, 2 still retains high potency against HUVECs, with an IC ₅₀ of 3.88 nM. This result is a significant step forward in the simplification of the overall cortistatin structure from a synthesis standpoint. However, 4 does not exhibit useful levels of activity (>1 mM) . These results are shown in Table 2, below.

Table 2

Substrate IC ₅₀ (nM) cortistatin A (1 ) 2.43 ^a , 1.8 ^b

δ ¹⁶ -cortistatin A (2) 3.88

17-ep/-cortistatin A (4) >1000

6d-g, 7a-f, 8e, 9a, 9d-e ^c >1000

[a] IC50 of synthetic cortistatin A tested by Pfizer, lnc

[b] IC50 of natural cortistatin A tested by Kobayashi group ^4a

[c] The TBS groups were removed prior to testing The results of 6e and 7e are from Sato et al ,

BIOSCI Biotechnol Biochem 2008, 722992-2997

The observed profound difference of biological activity clearly indicates that the C-17 stereochemistry is essential for biological behavior. Modelling studies suggest that Compounds 1, 2, and 4 exhibit rigid architectures that differ only in the angle in which the isoquinoline moiety would be presented to the active site. Several estrone model

compounds were also found to be inactive in the HUVEC screen.

In summation, two processes were identified for the production of either α- or β-oriented C-17 aryl steroids, conveniently using the C-17 ketone as a common starting material. Because of this divergence, it is now possible to efficiently produce both epimers of C-17 aryl steroids, thus adding the α-epimers to the cadre of unnatural biomolecules available for biological and other studies. The relevance and utility of such a transformation has been demonstrated by the synthesis of 1, its epimer 2, and biological evaluations thereof. Finally, the compelling finding that 2 retains much of the potency of 1 should considerably simplify SAR studies in this family.

EXPERIMENTAL SECTION

General procedures

All reactions were carried out under a nitrogen atmosphere with dry solvents using anhydrous conditions unless otherwise stated. Dry tetrahydrofuran (THF) , diethyl ether, dichloromethane (CH ₂ Cl ₂ ) , benzene, toluene, methanol (MeOH) , acetonitrile, 1, 2 -dimethoxyethane (DME), W, λf-dimethylformamide (DMF) , and triethylamine (Et ₃ N) were obtained by passing these previously degassed solvents through activated alumina columns. Reagents were purchased at the highest commercial quality and used without further purification, unless otherwise stated. Yields refer to chromatographically and spectroscopically ( ¹ H NMR) homogeneous materials, unless otherwise stated.

Reactions were monitored by thin layer chromatography (TLC) carried out on 0.25 mm E. Merck silica gel plates (60F-254) using UV light as the visualizing agent and an acidic mixture of anisaldehyde, phosphomolybdic acid, or eerie ammonium molybdate, or basic aqueous potassium permangante (KMnO ₄ ), and heat as developing agents. E. Merck silica gel (60, particle size 0.043-0.063 mm) was used for flash column chromatography. Preparative thin layer chromatography (PTLC) separations were carried out on 0.25 or 0.5 mm E. Merck silica gel plates (60F-254) .

NMR spectra were recorded on Bruker DRX- 600, DRX-500, and AMX-400 or Varian Inova-400 instruments and calibrated using residual undeuterated solvent as an internal reference (CHCl ₃ @ 7.26 ppm ¹ H NMR, 77.0 ppm ¹³ C NMR) . The following abbreviations (or combinations thereof) were used to explain the multiplicities: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet, b = broad. High-resolution mass spectra (HRMS) were recorded on Agilent LC/MSD TOF time-of -flight mass spectrometer by electrospray ionization time of flight reflectron experiments. IR spectra were recorded on a Perkin Elmer Spectrum BX FTIR spectrometer. Melting points were recorded on a Fisher-Johns 12-144 melting point apparatus . Optical rotations were obtained on a Pekin-Elmer 431 Polarimeter.

General Procedure for the Standardization of Raney Nickel (Ra-Ni)

Raney ^* 2800 Nickel {ca. 1 g of a lg/mL slurry in H ₂ O, pH = 9, Sigma-Aldrich) was placed in a vial. The water was removed by pipette, and the Ra-

Ni was washed by 5 seconds of shaking, followed by removal of the supernatant: first H ₂ O (2 x 2 mL) , then sat. aq. Rochelle's salt (2 x 2 mL) , then H ₂ O (10 x 2 mL) . After all washes, the Ra-Ni aqueous solution (pH=7) was stored under H ₂ O (1 mL) .

General Procedure for Hydrogenation

To a solution of styrene in i-PrOH/toluene (9:1, 0.01 M), was added the suspension of Ra-Ni prepared above (the Ra-Ni suspension was removed by 5.75' pipette from the thick bottom layer of the vial; 1 drop suspension per 0.1 mL solution) . The reaction flask was immersed in an oil bath preheated to 60 ⁰ C and stirred vigorously for 120 minutes. After cooling to ambient temperature, the reaction mixture was passed through Celite, the Ra- Ni washed with CH ₂ Cl ₂ , and the combined filtrates were concentrated in vacuo. The product was purified by flash column chromatography.

General procedure for Deoxygenation

To a solution of alcohol in toluene (0.01M) , was added the suspension of Ra-Ni prepared above (the Ra-Ni suspension was removed by 5.75' pipette from the thick bottom layer of the vial; 1 drop suspension per 0.1 mL solution) . The reaction flask was immersed in an oil bath preheated to 110 ⁰ C and stirred vigorously for 5 hours. After cooling to ambient temperature, the reaction mixture was passed through Celite, the Ra-Ni washed with CH ₂ Cl ₂ , and the combined filtrates were concentrated in vacuo. The product was purified by flash column chromatography.

General Reaction Procedure A

An aromatic bromide (ArBr; 3 equiv) was dissolved in Et ₂ O (0.63 M) and cooled to -78 ⁰ C. π-BuLi (2.5 M, 3.0 equiv) was added dropwise. After 40 minutes, the mixture was warmed up to room temperature and cannulated into a toluene solution of O-TBS-estrone [Fevig et al . , J. Org. Chem. 1987, 52:247-251] (0.1 M ₁ 1.0 equiv) at room temperature and stirred at that temperature for 40 minutes. The reaction was then quenched with sat. aq. NaHCO ₃ . The aqueous layer was extracted with EtOAc (3 times) . The combined organics were dried over MgSO ₄ , filtered, and concentrated in vacuo. The product was purified by flash chromatography on silica [Lecomte et al, Tetrahedron 2003, 59:2169-2176] .

Alcohol 8a

8a

Alcohol 8a was prepared from O-TBS-estrone (50 mg, 0.129 mmol) according to general reaction procedure A. Purification by flash chromatography (1:2 hexanes: CH ₂ Cl ₂ ) afforded alcohol 8a (39 mg, 0.084

mmol, 65%) as a white solid (mp 156-159°C) : R _f = 0.53 (1:4 pentanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +46.8° (c = 0.95, CH ₂ Cl ₂ ) ; IR (neat) v _max = 3459, 2929, 2360, 1495, 1252 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.51 (d, J = 7.7 Hz, 2 H) , 7.44 (t, J = 7.6 Hz, 2 H) , 7.36 (dd, J = 13.0, 6.1Hz, 1 H) , 7.09 (d, J = 8.5 Hz, 1 H) , 6.65 (d, J = 8.4 Hz, 1 H) , 6.63 (s, J = 2.6 Hz, 1 H) , 2.96 - 2.84 (m, 2 H) , 2.54 (ddd, J = 14.5, 9.7, 5.0 Hz, I H) ,

2.26 (dd, J =, 13.1, 4.3 Hz, IH) , 2.22 - 2.12 (m, 1 H) , 2.05 - 1.98 (m, 3 H) , 1.98 - 1.91 (m, 1 H) , 1.77 - 1.69 (m, 2 H) , 1.61 - 1.46 (m, 3 H) , 1.43 - 1.32 (m, 1 H) , 1.19 (s, 3 H) , 1.07 (s, 9 H) , 0.71 (dt, J = 12.9 , 4.0 Hz, IH) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz,

CDCl ₃ ) δ 153.4, 146.1, 137.8, 133.2, 127.5 (2 C), 127.4 (2 C), 127.0, 126.1, 120.0, 117.2, 86.1, 48.3, 47.1, 43.5, 39.6, 38.8, 33.8, 29.8, 27.6, 26.4, 25.9 (3 C), 24.3, 18.3, 15.0, -4.2 (2 C); HRMS (ESI-TOF) calcd for C ₃₀ H ₄₃ O ₂ Si [M+H] ⁺ : 463.3027; found: 463.3020.

Alcohol 8b

8b

Alcohol 8b was prepared from O-TBS-estrone (48 mg, 0.125 mmol) according to general reaction procedure A. Purification by flash chromatography (1:2 hexanes: CH ₂ Cl ₂ ) afforded alcohol 8b (35 mg,

0.070 mmol, 56%) as a white solid (mp 120-123 ⁰ C) : R _f =

0.36 (1:5 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +38.2° (c = 0.45, CH ₂ Cl ₂ ) ; IR (neat) v _max = 3476, 2931, 1496, 1253 cm ^"1 ; 1H NMR (500 MHz, CDCl ₃ ) δ 7.30 (d, J = 8.2 Hz, 2 H) , 7.16 (d, J = 7.9 Hz, 2 H) , 7.00 (d, J = 8.5 Hz, 1 H) , 6.56 (dd, J = 8.4 , 2.6 Hz, 1 H) , 6.53 (d, J = 2.5, 1 H) , 2.86 - 2.74 (ra, 2 H) , 2.42 (ddd, J = 14.6, 9.8, 5.1 Hz, 1 H) , 2.36 (s, 3 H) , 2.17 - 2.08 (m, 2 H) , 1.93 - 1.83 (ra, 4 H) , 1.66 - 1.57 (m, 2 H) , 1.51 - 1.35 (m, 3 H) , 1.33 - 1.24 (m, 1 H) , 1.09 (s, 3 H) , 0.97 (s, 9 H) , 0.65 (dt, J = 12.9 , 4.1 Hz, IH) , 0.18 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.3, 143.2, 137.9, 136.5, 133.3, 128.2 (2 C) , 127.4 (2 C) , 126.2, 120.0, 117.2, 86.0, 48.3, 47.1, 43.5, 39.6, 38.8,

33.8, 29.8, 27.6, 26.4, 25.9 (3 C) , 24.2, 21.1, 18.3,

14.9, -4.2 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₁ H ₄₄ O ₂ SiNa [M+Na] ⁺ : 499.3003; found: 499.2988.

Alcohol 8c

δc

Alcohol 8c was prepared from O-TBS-estrone (49 mg, 0.127 mmol) according to general reaction procedure A. Purification by flash chromatography (1:2 hexanes: CH ₂ Cl ₂ ) afforded alcohol 8c (25 mg, 0.051 mmol, 40%) as a white foam: R _f = 0.30 (1:5 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +38.2° (c = 0.3, CH ₂ Cl ₂ ) ; IR

(neat) v _max = 3463, 2928, 1607, 1497, 1251 cm ^"1 ; ¹ H NMR

(500 MHz, CDCl ₃ ) δ 7.33 (d, J = 8.5 Hz, 2 H) , 7.01 (d, J = 8.4 Hz, 1 H) , 6.89 (d, J = 8.7 Hz, 2 H) , 6.57

(dd, J = 8.4, 2.3 Hz, 1 H) , 6.54 (d, J = 2.0 Hz, 1 H) , 3.83 (s, 3 H) , 2.87 - 2.75 (m, 2 H) , 2.41 (ddd, J = 14.4, 9.7, 4.9 Hz, 1 H) , 2.18 - 2.10 (m, 2 H) , 1.93 - 1.83 (m, 4 H) , 1.66 - 1.57 (m, 2 H) , 1.51 - 1.21

(m, 4 H), 1.09 (s, 3 H), 0.98 (s, 9 H), 0.67 (dt, J = 12.9, 4.0 Hz, IH), 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) 5 158.3, 153.3, 138.2, 137.9, 133.2, 128.6 (2 C), 126.1, 120.0, 117.2, 112.8 (2 C), 85.8, 55.4, 48.3, 47.0, 43.5, 39.6, 38.8, 33.7, 29.8, 27.6, 26.4, 25.8 (3 C), 24.2, 18.3, 14.9, -4.3 (2 C); HRMS (ESI- TOF) calcd for C ₃ iH ₄₅ O ₃ Si [MH-H] ⁺ : 493.3132; found: 493.3130.

Alcohol 8d

8d

Alcohol 8d was prepared from O-TBS-estrone (50 mg, 0.131 mmol) according to general reaction procedure A. Purification by flash chromatography (2:3 hexanes: EtOAc) afforded alcohol 8d (34 mg, 0.073 mmol, 56%) as a white foam: R _f = 0.3 (1:2 hexanes : EtOAc) ; [α] ^D ₂₀ = +39.0° (c = 0.41, CH ₂ Cl ₂ ); IR (neat) v _max = 3237, 2929, 1496, 1252 cm ^"1 ; ¹ H NMR(400

MHz, CDCl ₃ ) δ 8.56 (s, 1 H) , 8.41 (d, J = 3.8 Hz, 1 H) , 7.79 (d, J = 7.9 Hz 1 H) , 7.27 - 7.25 (m, I H) , 7.02 (d, J = 8.4 Hz, 1 H) , 6.59 (dd, J = 8.4, 2.5 Hz, 1 H) , 6.55 (d, J = 2.4, 1 H) , 3.65 - 3.35 (b, 1 H) , 2.89 - 2.76 (m, 2 H) , 2.39 (ddd, J = 14.5, 9.6, 5.1 Hz, 1 H) , 2.23 - 2.11 (m, 2 H) , 1.93 - 1.83 (m, 3 H) , 1.72 - 1.63 (m, 2 H) , 1.55 - 1.39 (m, 2 H) , 1.36 - 1.24 (m, 2 H) , 1.13 (s, 3 H) , 0.99 (s, 9 H) , 0.56 (dt, J = 12.7, 3.9 Hz, IH) , 0.20 (s, 6 H) ; ¹³ C NMR (100 MHz, CDCl ₃ ) δ 153.3, 148.5, 147.74, 141.8, 137.7, 135.4, 132.9, 126.1, 122.4, 120.0, 117.2, 84.6, 48.3, 47.2, 43.4, 39.5, 38.5, 33.5, 29.7, 27.5, 26.2, 25.8 (3 C) , 24.1, 18.2, 14.8, -4.3 (2 C) ; HRMS (ESI-TOF) calcd for C ₂₉ H ₄₂ NO ₂ Si [M+H] ⁺ : 464.2979; found: 464.2984.

Alcohol 8e

To a THF solution of 7-bromoisoquinoline (40 mg, 0.193 mmol, 1 mL, 0.19 M ₁ 3 equiv) was added n-BuLi (88μL, 2.3 M ₁ 0.19 minol, 3 equiv) dropwise at -78 ⁰ C. After 40 minutes, TMEDA (88μL, 0.58 mmol, 9 equiv) was added and the mixture was stirred at -78 ⁰ C for 10 minutes [Foy et al . , Chembiochem 2003, 4:494-503 ] . A THF solution of O-TBS-estrone (25

mg, 0.065 mmol, 1 equiv, 0.3 mL, 0.22 M) was added and the reaction mixture was stirred for 40 minutes at -78 ⁰ C. The reaction was quenched with sat. aq. NaHCO ₃ (10 mL) . The aqueous layer was extracted with EtOAc (20 mL x 4) . The combined organics were dried over MgSO ₄ , filtered, and concentrated in vacuo. Chromatography on silica (30% EtOAc in hexanes) afforded alcohol 8e (25 mg, 0.049 mmol, 74%) as a yellow solid (mp 183-185 ⁰ C) : R _f = 0.31 (1:1

EtOAc : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +16.9° (c = 0.54, CH ₂ Cl ₂ ) ; IR

(neat) v _max = 3210, 1496, 1285, 1251, 837 cm ^"1 ; ¹ H NMR

(500 MHz, CDCl ₃ ) δ 9.28 (s, 1 H), 8.51 (d, J = 4.8 Hz, 1 H), 7.88 (d, J = 7.8 Hz, 2 H), 7.79 (d, J = 8.9 Hz, 1 H), 7.65 (d, J = 5.6 Hz, 1 H), 6.95 (d, J = 8.3 Hz, 1 H), 6.55 - 6.50 (m, 2 H), 2.73 - 2.87 (m, 2 H), 2.59 (ddd, J = 14.8, 9.8, 5.1 Hz, I H), 2.25 (ddd, J = 17.1, 12.5, 4.4 Hz, 1 H), 2.10 - 2.00 (m, 2 H), 1.96 - 1.91 (m, 1 H), 1.79 (td, J = 11.2, 4.0 Hz, 1 H), 1.75 - 1.65 (m, 2 H), 1.55 - 1.45 (m, 1 H), 1.47 - 1.32 (m, 1 H), 1.33 - 1.22 (m, 2 H), 1.15 (s, 3 H), 0.95 (s, 9 H), 0.57 (td, J = 12.8, 4.1 Hz, 1 H), 0.16 (s, 6H); ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.2, 152.8, 145.2, 142.9, 137.6, 134.6, 132.8, 130.8, 127.9, 125.9, 125.3, 125.2, 120.0, 119.8, 117.0, 86.1, 48.3, 47.4, 43.3, 39.5, 38.9, 33.7, 29.6, 27.4, 26.1, 25.7 (3 C), 24.2, 18.1, 14.8, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₃ H ₄₄ NO ₂ Si [M+H] ⁺ : 514.3136; found: 514.3140.

Alcohol 8f

O-TBS-estrone alcohol 8f

4-FC ₆ H ₄ I (0.78 mmol, 173 mg, 90 μl, 1.1 equiv) was dissolved in toluene (8.1 mL, 0.96 M) and cooled to -78 ⁰ C, after which π-BuLi (2.27 M ₁ 0.78 mmol, 378 μl, 1.1 equiv) was added dropwise. After 40 minutes, the resulting ArLi solution was warmed up to room temperature and cannulated into O-TBS-estrone (300 mg, 0.781 mmol, 1 equiv) in toluene (3.9 mL, 0.2 M) , and the mixture was stirred for 30 minutes. The reaction was then quenched with sat. aq. NaHCO ₃ (10 ml) . The aqueous layer was extracted with EtOAc (20 ml x 4) . The combined organics were dried over MgSO ₄ , filtered, and concentrated in vacuo. Chromatography on silica (6% EtOAc in hexanes) afforded alcohol 8f (263.5 mg, 0.549 mmol, 70%) as a white solid (mp 155- 159 ⁰ C) : Rf = 0.32 (1:4 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +55.1° (c = 1.45, CH ₂ Cl ₂ ); IR (neat) v _max = 3462, 2928, 1605, 1496, 1252 cm ^"1 ; ¹ H NMR(400 MHz, CDCl ₃ ) δ 7.37 (dd, J = 7.5, 5.2 Hz, 2 H), 7.08 - 7.00 (m, 3 H), 6.57 (d, J = 8.5 Hz, 1 H), 6.54 (s, 1 H), 2.86 - 2.75 (m, 2 H), 2.44 (ddd, J = 14.5, 9.7, 5.0 Hz, 1 H), 2.17 - 2.10 (m, 2 H), 1.92 - 1.83 (m, 4 H), 1.67 - 1.58 (m, 2 H) , 1.51 - 1.38 (m, 2 H), 1.35 - 1.25 (m, 2 H), 1.09 (s, 3 H), 0.98 (s, 9 H), 0.60 (dt, J = 12.8, 3.8 Hz,

IH) , 0.18 (s, 6 H) ; ¹³ C NMR (125 MHz ₇ CDCl ₃ ) δ 162.6 (d, J _CF = 245.3 Hz) , 154.1, 142.5 (d, J _CF = 3.0 Hz) ,

138.6, 133.8, 129.9 (d, J _CF = 7.7 Hz, 2 C) , 126.9,

120.7, 118.0, 114.9 (d, J _CF = 21.0 Hz, 2 C) , 86.6,

49.0, 47.8, 44.3, 40.3, 39.7, 34.4, 30.5, 28.3,

27.1, 26.6 (3 C) , 24.9, 19.1, 15.6, -4.3 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₂ FO ₂ Si [M+H] ⁺ : 481.2932; found: 481.2944.

Alcohol 8g

Alcohol 8g was prepared from O-TBS-estrone (202 mg, 0.527 mmol) according to general reaction procedure A. Purification by flash chromatography (1:2 hexanes: CH ₂ Cl ₂ ) afforded alcohol 8g (190 mg, 0.358 mmol, 68%) as a white foam: R _f = 0.6 (1:4 pentanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +40.2° (c = 0.51, CH ₂ Cl ₂ ) ; IR (neat) v _max = 3443, 2927, 1496, 1328 cm ^"1 ; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.60 (d, J = 8.5 Hz, 2 H) , 7.54 (d, J = 8.5 Hz, 2 H) , 7.00 (d, J = 8.4 Hz, I H) , 6.57 (dd, J = 8.4, 2.2 Hz, 1 H) , 6.54 (s, 1 H) , 2.88 - 2.75 (m, 2 H) , 2.44 (ddd, J = 14.3, 9.6, 4.9 Hz, I H) , 2.21 - 2.10 (m, 2 H) , 1.96 - 1.83 (m, 4 H) , 1.73 - 1.59 (m, 2 H) , 1.55 - 1.20 (m, 4 H) , 1.11 (s, 3 H) , 0.98 (s, 9 H) , 0.55 (dt, J = 12.7, 3.7 Hz, IH) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.4, 150.1, 137.7, 132.9,

129.1 (q, JCF = 32.2 Hz) , 127.85 (2 C) , 124.4 (q, J _CF = 271.8 Hz) , 124.3 (q, J _CF = 3.57 Hz, 2 C) , 126.1, 120.0, 117.2, 86.1, 48.4, 47.3, 43.4, 39.6, 38.9, 33.6, 29.7, 27.5, 26.2, 25.8 (3 C) , 24.2, 18.3, 14.9, -4.3 (2 C) ; HRMS (ESI-TOF) calcd for C _3I H ₄₂ F ₃ O ₂ Si [M+H] ⁺ : 531.2901; found: 531.2905.

Alcohol 10

O-TBS-estrone (30 mg, 0.078 mmol, 1 equiv) was dissolved in toluene (0.78 raL, 0.1 M) . n-BuLi

(2.5 M, 0.23 mL, 3 equiv) was added dropwise at room temperature and stirred for 40 minutes. The reaction was then quenched with sat. aq. NaHCO ₃ (5 mL) . The aqueous layer was extracted with EtOAc (3 x 10 mL) . The combined organics were dried over MgSO ₄ , filtered, and concentrated in vacuo. Chromatography on silica

(10% EtOAc in hexanes) afforded alcohol 10 (22.5 mg,

0.051 mmol, 65 %) as a white solid (mp 85-89°C) : R _f = 0.30 (1 :4 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +26.9° (c = 0.84 , CH ₂ Cl ₂ ) ; IR (neat) v _max = 3443, 2930, 1605, 1496, 1286,

1252, 954 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.12 (d, J = 8.5 Hz, 1 H) , 6.61 (dd, J = 8.4, 2.5 Hz, 1 H) , 7.08 - 7.00 (m, 3 H) , 6.55 (d, J = 2.4 Hz, 1 H) , 2.86 - 2.75 (m, 2 H) , 2.34 - 2.26 (m, 1 H) , 2.18 - 2.13 (m, 1 H) , 2.05 - 1.99 (m, 1 H) , 1.90 - 1.85 (m, 1 H) , 1.66 - 1.51 (m, 6 H) , 1.51 - 1.49 (m, 4 H) , 1.43 -

1.23 (m, 6 H) , 0.98 (s, 9 H) , 0.95 (t, J = 7.1 Hz, 3H) , 0.91 (s, 3 H) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.3, 137.9, 133.1, 126.1, 126.1, 119.9, 117.1, 83.5, 49.5, 46.7, 43.9, 39.6, 36.5, 34.4, 31.6, 29.7 , 27.6, 26.3 , 25.9, 25.7 (3 C) , 23.6, 23.4, 18.2 , 14.4 , 14.3 , -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₂₈ H ₄₇ O ₂ Si [M+H] ⁺ : 443.3340 ; found: 443.3324

General Procedure B

Vinyl triflate [Liu et al . , J. Org. Chem. 1996, 61:6693-6699] (1.0 equiv) , ArB(OH) ₂ (1.3 equiv) and dichlorofl, 1' -ferrocenylbis (diphenylphosphine) ] - palladium(II) [Pd(dppf) Cl ₂ ,- (0 mmol%] were dissolved in DME (0.1 M) in a reaction vessel, and 2 M NaOH (1.3 equiv) was added. The solution was degassed for 10 minutes by bubbling with Ar under sonication. The reaction was then immersed in an oil bath preheated to 80 ⁰ C for 1 hour. The reaction mixture was permitted to cool to ambient temperature, diluted with EtOAc, and washed with sat. aq. NaHCO ₃ . The aqueous layer was extracted with EtOAc (3 times) . The combined organic portions were washed with sat. aq. NaCl, dried over MgSO ₄ , filtered, and concentrated in vacuo. The product was purified by flash chromatography on silica. (Note: vinyl triflate was prepared according to Liu et al . , above, and 90% yield from O-TBS-Estrone . )

Styrene 6a

Styrene 6a was prepared from the vinyl triflate (48 mg, 0.093 mmol) according to general procedure B. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded styrene 6a (34 mg, 0.076 mmol, 82%) as a white solid (mp 108-111 ⁰ C) : R _t = 0.27 (9:1 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +29.7° (c = 0.4, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2932, 1495, 1258 cm ^"1 ; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.41 (dd, J = 8.3, 1.3 Hz, 2H) , 7.33 - 7.28 (m, 2 H) , 7.25 - 7.21 (m, 1 H) , 7.12 (d, J = 8.4 Hz, 1 H) , 6.62 (dd, J = 8.4, 2.6 Hz, I H) , 6.58 (d, J = 2.6 Hz, I H) , 5.94 (dd, J = 3.2, 1.8 Hz, 1 H) , 2.94 - 2.80 (m, 2 H) , 2.38 - 2.27 (m, 3 H) , 2.20 (dd, J = 8.5, 2.3 Hz, IH) , 2.12 (ddd, J = 15.5,

11.4, 1.7 Hz, 1 H) , 1.98 - 1.92 (m, 1 H) , 1.80 (dt, J = 11.3, 6.5 Hz, 1 H) , 1.72 - 1.61 (m, 3 H) , 1.52 - 1.41 (m, 1 H) , 1.07 (s, 3 H) , 0.98 (s, 9 H) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 155.1, 153.5, 138.0, 137.5, 133.5, 128.3 (2 C) , 127.4, 126.9, 126.8 (2 C) , 126.0, 120.1, 117.2, 57.0, 47.7, 44.3, 37.4, 35.7,

31.5, 29.7, 27.9, 26.7, 25.9 (3 C) , 18.3, 16.9, -4.2 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₁ OSi [MH-H] ⁺ :

445.2921; found: 445.2903.

Styrene 6b

Styrene 6b was prepared from the vinyl triflate (49 mg, 0.095 mmol) according to general procedure B. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded styrene 6b (37 mg, 0.081 mmol, 85%) as a white solid (mp 103-107 ⁰ C) : R _f = 0.31 (10% CH ₂ Cl ₂ in hexanes) ; [α] ^D ₂₀ = +24.2° (c = 0.75, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2931, 1738, 1494, 1251 cm ^"1 ; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.32 (d, J = 8.1 Hz, 2 H) , 7.14 (d, J = 8.0 Hz, 3 H) , 6.63 (dd, J = 8.4, 2.6 Hz, I H) , 6.59 (d, J = 2.5 Hz, I H) , 5.91 (dd, J = 3.2, 1.7 Hz, 1 H) , 2.95 - 2.81 (m, 2 H) , 2.40 (s, 1 H) , 2.36 (s, 3 H) , 2.34 - 2.28 (m, 2 H) , 2.21 (dd, J = 8.4 , 2.4 Hz, 1 H) , 2.11 (ddd, J = 15.4, 11.3, 1.6 Hz, 1 H) , 1.99 - 1.93 (m, 1 H) , 1.79 (dt, J = 11.3, 6.4 Hz, 1 H) , 1.73 - 1.62 (m, 3 H) , 1.54 - 1.42 (m, 1 H) , 1.07 (s, 3 H) , 1.00 (s, 9 H) , 0.21 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 154.8, 153.3, 137.9, 136.4, 134.4, 128.8 (2 H) , 126.6 (2 H) , 126.3, 125.8, 120.0, 117.2, 56.8, 47.5, 44.2, 37.3, 35.3, 31.3, 29.6, 27.8, 26.6, 25.7 (3 H) , 21.1, 18.2, 16.7, -4.4 (2 H) ; HRMS (ESI-TOF) calcd for C _3x H ₄₃ OSi [M+H] ⁺ : 459.3078; found: 459.3087.

Styrene 6c

Styrene 6c was prepared from the vinyl triflate (51 mg, 0.099 mmol) according to general procedure B. Purification by flash chromatography

(15 : 1 hexanes : CH ₂ Cl ₂ ) afforded styrene 6c (38 mg, 0.080 mmol, 81%) as a white solid (mp 96-101°C) : Rf = 0.28 (4 :1 hexanes : CH ₂ Cl ₂ ) ; [α] ^D ₂₀ = +25.8° (c = 0.31, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2928, 1497, 1251 cm ^"1 ; ¹ H NMR

(400 MHz, CDCl ₃ ) δ 7.32 (d, J = 8.8 Hz, 2 H) , 7.13 (d, J = 8.4 Hz, 1 H) , 6.86 (d, J = 8.8 Hz, 2 H) , 6.62

(dd, J = 8.4 , 2.6 Hz, 1 H) , 6.58 (d, J = 2.5 Hz, 1 H) , 5.85 (dd, J = 3.1, 1.7 Hz, 1 H) , 3.82 (s, 3 H) , 2.95 - 2.81 (m, 2 H) , 2.39 - 2.27 (m, 3 H) , 2.19 (dd, J = 8.5 , 2.3 Hz, 1 H) , 2.10 (ddd, J = 15.4 , 11.3 , 1.6 Hz, 1 H) , 1.98 - 1.92 (m, 1 H) , 1.78 (dt, J = 11.3 , 6.5 Hz, 1 H) , 1.72 - 1.61 (m, 3 H) , 1.47 (ddd, J = 24.1, 11.7 , 6.8 Hz, 1 H) , 1.05 (s, 3 H) , 0.99 (s, 9 H) , 0.20 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 158.5, 154.4, 153.3, 137.9, 133.3, 129.9, 127.8 (2 C) , 125.8, 125.4 , 120.0, 117.1, 113.5 (2 C) , 56.8 , 55.2, 47.5, 44.2, 37.3 , 35.6, 31.2, 29.6, 27.8 , 26.6, 25.7

(3 C) , 18.2, 16.7, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₁ H ₄₃ O ₂ Si [M+H] ⁺ : 475.3027; found: 475.3010.

Styrene 6d

styrene 6d

Styrene 6d was prepared from the vinyl triflate (49 mg, 0.094 mmol) according to general procedure B. Purification by flash chromatography

(2:1 EtOAc:hexanes) afforded styrene 6d (26 mg, 0.058 mmol, 62%) as a white foam: R _f = 0.5 (1:1 hexanes : EtOAc) ; [α] ^D ₂₀ = +24.1° (c = 0.85, CH ₂ Cl ₂ ) ; IR

(neat) v _max = 2930, 1496, 1380, 1253, 1188 cm ^"1 ; ¹ H NMR

(500 MHz, CDCl ₃ ) δ 8.66 (s, 1 H) , 8.48 (s, 1 H) , 7.71(d, J = 7.88 Hz, 1 H) , 7.71 - 7.69 (m, 1 H) , 7.12

(d, J = 8.42 Hz, 1 H) , 6.62 (dd, J = 8.4, 2.6 Hz, 1 H) , 6.58 (d, J = 2.6 Hz, 1 H) , 6.03 (dd, J = 3.2, 1.8 Hz, 1 H) , 2.94 - 2.82 (m, 2 H) , 2.39 - 2.27 (m, 3 H) , 2.18 - 2.10 (m, 2 H) , 1.98 - 1.92 (m, 1 H) , 1.81 (dt, J = 11.5, 6.5 Hz, 1 H) , 1.72 - 1.60 (m, 3 H) , 1.48

(ddd, J = 17.7, 11.8, 6.0 Hz, 1 H) , 1.05 (s, 3 H) , 0.98 (s, 9 H) , 0.20 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.5, 151.7, 147.3, 147.2, 137.9, 133.2, 129.6, 126.9, 125.9, 123.6, 120.1, 117.3, 113.5, 56.9, 47.9,

44.2, 37.3, 35.5, 31.7, 29.6, 27.9, 26.6, 25.9 (3 C) ,

18.3, 16.9, -4.2 (2 C) ; HRMS (ESI-TOF) calcd for C ₂₉ H ₄₀ NOSi [M+H] ⁺ : 446.2874; found: 446.2863.

General procedure C

To a solution of alcohol (1.0 equiv) in benzene (0.03 M) was added methyl N- (triethyl- ammoniumsulphonyl ) carbamate (5.0 equiv) . The reaction mixture so formed was then immersed in a preheated oil bath at 50 ⁰ C. After 2 hours, the reaction mixture was permitted to cool to ambient temperature and diluted with EtOAc. The diluted reaction mixture was washed with H ₂ O and sat. aq. NaCl, dried over MgSO ₄ , filtered, and concentrated in vacuo. The product was purified by flash chromatography on silica.

Styrene 6f

Styrene 6f was prepared from alcohol 8f (117 mg, 0.243 mmol) according to general procedure C. Purification by flash chromatography (1:6 CH ₂ Cl ₂ :hexanes ) afforded styrene 6f (92 mg, 0.197 mmol, 81%) as a white solid (mp 140-144 ⁰ C) : R _f = 0.33

(1:6 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +32.5° (c = 0.54, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1497, 1255 cm ^"1 ; ¹ H NMR

(400 MHz, CDCl ₃ ) δ 7.39 (dd, J = 8.7, 5.5 Hz, 2 H) , 7.17 (d, J = 8.4 Hz, 1 H) , 7.03 (t, J = 8.8 Hz, 2 H) , 6.68 (dd, J = 8.4, 2.5 Hz, 1 H) , 6.63 (d, J = 2.2 Hz, I H) , 5.92 (dd, J = 2.8, 1.5 Hz, I H) , 2.99 - 2.85

(m, 2 H) , 2.42 - 2.31 (m, 3 H) , 2.19 - 2.11 (m, 2 H) , 2.05 - 1.97 (m, 1 H) , 1.82 (dt, J = 11.3, 6.5 Hz, 1 H) , 1.76 - 1.66 (m, 3 H) , 1.51 (dq, J = 12.2, 11.8, 6.8 Hz, 1 H) , 1.05 (s, 3 H) , 1.04 (s, 9 H) , 0.25 (s, 6 H) ; ¹³ C NMR (100 MHz, CDCl ₃ ) δ 162.1 (d, J _CF = 245.7 Hz) 154.2, 153.5, 138.0, 133.5 (d, J _CF = 3.3 Hz) , 128.4 (d, J _CF = 7.7 Hz, 2 C) , 127.1, 126.0, 120.2, 117.3, 115.1 (d, J _CF = 21.1 Hz, 2 C) , 57.0, 47.8, 44.3, 37.5, 35.7, 31.4, 29.7, 27.9, 26.7, 25.9 (3 C) , 18.3, 16.8, -4.2 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄ iFOSi [MH-H] ⁺ : 463.2872; found: 463.2835.

Styrene 6g

Styrene 6g was prepared from alcohol 8g (100 mg, 0.188 mmol) according to general procedure C. Purification by flash chromatography (1:5 CH ₂ Cl ₂ : hexanes) afforded styrene 6g (82 mg, 0.160 mmol, 85%) as a white solid (mp 75-81°C) : R _f = 0.32 (1:6 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +18.8° (c = 0.67, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1497, 1325, 1125 cm ^"1 ;

¹ H NMR (400 MHz, CDCl ₃ ) δ 7.58 (dd, J = 26.4, 8.3 Hz, 4 H) , 7.18 (d, J = 8.4 Hz, 1 H) , 6.69 (dd, J = 8.4, 2.6 Hz, 1 H) , 6.65 (d, J = 2.4 Hz, 1 H) , 6.09 (dd, J = 3.1, 1.7 Hz, 1 H) , 3.00 - 2.81 (m, 2 H) , 2.46 - 2.32 (m, 3 H) , 2.32 - 2.26 (m, 2 H) , 2.05 - 1.98 (m, 1 H) , 1.85 (dt, J = 11.4, 6.5 Hz, 1 H) , 1.78 - 1.65 (m, 3 H) , 1.56 - 1.43 (m, 1 H) , 1.13 (s, 3 H) , 1.05 (s, 9 H) , 0.26 (s, 6 H) ; ¹³ C NMR (100 MHz, CDCl ₃ ) δ 154.0, 153.5, 141.0, 137.9, 133.2, 129.5, 128.7 (q, JCF = 32.3 Hz) , 126.9, 126.5 (q, J _CF = 32.3 Hz) , 125.9, 125.1 (q, JCF = 3.7 Hz, 2 C) , 121.7 (q, J _CF = 269.7 Hz) , 120.1, 117.3, 56.9, 47.8, 44.2, 37.3, 35.5, 31.6, 29.6, 27.8, 26.6, 25.8 (3 C) , 18.2, 16.9, -4.3 (2 C) ; HRMS (ESI-TOF) calcd for C ₃ iH ₄ iF ₃ OSi [M+H] ⁺ : 513.2795; found: 513.2805.

Styrene 6e

To a solution of vinyl triflate (134 mg, 0.26 mmol, 1.0 equiv) in DMSO (2.6 mL, 0.1 W) was added 7-trimethylstannylisoquinoline (152 mg, 0.52 mmol, 2.0 equiv), CuCl (254 mg, 2.6 mmol, 10 equiv), LiCl(IlO mg, 2.6 mmol, 10 equiv) and Pd(PPh ₃ J ₄ (300 mg, 0.26 mmol, 0.1 equiv) . The solution was bubbled with Ar under sonication for 10 minutes. The reaction mixture so formed was then immersed in a preheated oil bath at 60 ⁰ C. After 2 hours, the

reaction was permitted to cool to ambient temperature and diluted with EtOAc (10 mL) and washed with 5% NH ₄ OH (10 mL) . The aqueous layer was extracted with EtOAc (10 mL x 4) . The combined organic portions were washed with sat. aq. NaCl (20 mL) , dried over MgSO ₄ , filtered, and concentrated in vacuo. Chromatography on silica (1:4 EtOAc :hexanes) afforded Styrene 6e (103 mg, 0.208 mmol, 79%) as a white foam:

Rf = 0.35 (1:3 EtOAc : hexanes) ; [α] ^D ₂₀ = +22.5° (c = 0.08, CH ₂ Cl ₂ ); IR (neat) v _max = 2925, 2854, 1604, 1496, 1250, 954, 840, 781 cm ^"1 ; ¹ H NMR (600 MHz, CDCl ₃ ) δ 9.23 (S, 1 H), 8.48 (d, J = 5.6 Hz, 1 H), 7.95 (s, 1 H), 7.77 (dd, J = 15.8, 8.5 Hz, 2 H), 7.62 (d, J = 5.5 Hz, 1 H) , 7.14 (d, J = 8.4 Hz, 1 H) , 6.63 (dd, J = 8.1, 2.0 Hz, IH), 6.59 (s, I H) , 6.15 (d, J = 1.2 Hz, 1 H), 2.95 - 2.81 (m, 2 H), 2.43 - 2.35 (m, 1 H), 2.03 - 1.94 (m, 1 H), 1.86 (ddd, J = 17.9, 11.4, 6.5 Hz ,1 H), 1.78 - 1.66 (m, 2 H), 1.53 - 1.46 (m, 1 H), 1.40 - 1.28 (m, 2 H), 1.15 (s, 3 H), 0.98 (s, 9 H), 0.88 (t, J = 6.8 Hz, 1 H), 0.20 (s, 6H); ¹³ C NMR (150 MHz, CDCl ₃ ) δ 154.1, 153.3, 152.6, 142.7, 137.8, 136.2, 134.7, 133.1, 130.2, 129.1, 128.8, 126.2, 125.8, 123.8, 124.0, 120.2, 120.0, 117.0, 56.9, 47.8,

44.1, 37.2, 35.6, 31.5, 27.7, 26.5, 25.7 (3 C),

18.2, 16.8, 1.0, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₃ H ₄₂ NO ₂ Si [M+H] ⁺ : 496.3030; found: 496.3036.

General Procedure D

To a solution of the styrene in i-PrOH/toluene (9:1, 0.01 M), was added the suspension of Ra-Ni prepared as previously discussed (the Ra-Ni suspension was removed by 5.75' pipette from the thick bottom layer of the vial; 1 drop suspension per 0.1 mL solution) . The reaction flask was immersed in an oil bath preheated to 60 ⁰ C and stirred vigorously for 120 minutes. After cooling to ambient temperature, the reaction mixture was passed through Celite, the Ra-Ni washed by CH ₂ Cl ₂ , and the combined filtrates were concentrated in vacuo. The product was purified by flash column chromatography.

Compound 7a

Compound 7a was prepared from Styrene 6a (15 mg, 0.033 mmol) according to general procedure D. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded Compound 7a (14.3 mg, 0.032 mmol, 97%) as a white solid (mp 110-113 ⁰ C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes); [α] ^D ₂₀ = +3.1° (c = 0.48, CH ₂ Cl ₂ ); IR (neat) v _max = 2925, 1495, 1253 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) 6 7.31-7.19 (m, 5H) , 7.11 (d, J = 8.5 Hz, 1 H), 6.60 (dd, J = 8.5, 2.5 Hz, 1 H), 6.55 (d, J = 2.5 Hz, 1 H), 2.85 - 2.82 (m, 3 H), 2.78 (t, J = 10.0 Hz, 1 H), 2.28 - 2.24 (m, 2 H), 2.19 - 2.12 (m, 1 H),

2.05 - 1.87 (m, 3 H) , 1.72 - 1.70 (m, 1 H) , 1.48 - 1.42 (m, 6 H) , 0.98 (s, 9 H) , 0.51 (s, 3 H) , 0.18 (s, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.2, 141.1, 137.9, 133.3, 128.7 (2 C) , 127.7 (2 C) , 126.1, 126.0, 119.0, 57.1, 55.3, 44.6, 39.2, 37.7, 29.7 (2 C) , 27.9, 26.3, 26.1, 25.7 (3 C) , 24.2, 18.2, 12.8, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₃ OSi [M+H] ⁺ : 447.3078; found: 447.3078.

Compound 7b

7b

Compound 7b was prepared from Styrene 6b (17 mg, 0.037 mmol) according to general procedure D. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded 7b (16.7 mg, 0.036 mmol, 98%) as a white solid (mp 108-112 ⁰ C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +5.1° (c = 0.82, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1497, 1254 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.14-7.10 (m, 5 H), 6.60 (dd, J = 8.5 , 2.5 Hz, 1 H) , 6.55 (d, J = 2.5 Hz, 1 H) , 2.87 - 2.78 (m, 3 H) , 2.74 (t, J = 10.0 Hz, 1 H) , 2.33 (s, 3 H) , 2.27 - 2.24 (m, 2 H) , 2.14 - 2.09 (m, 1 H) , 2.05 - 1.86 (m, 3 H) , 1.71 - 1.69 (m, 1 H) , 1.46 - 1.40 (m, 6 H) , 0.98 (s, 9 H) , 0.51 (s, 3 H) , 0.19 (s, 6 H) ; ¹³ C NMR δ 153.2, 138.0, 137.9, 135.4, 133.4, 128.6 (2 C) , 128.4 (2 C) , 126.1, 119.9, 117.1, 56.8, 55.3, 44.4, 44.1,

39.2, 37.8, 29.7, 26.33, 26.29, 25.7 (3 C) , 24.2, 21.0, 18.2, 12.8, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₃ OSi [M+H] ⁺ : 461.3234; found: 461.3236.

Compound 7 c

7c

Compound 7a was prepared from Styrene 6c (15 mg, 0.031 mmol) according to general procedure D. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded 7c (14.0 mg, 0.029 mmol, 93%) as a white solid (mp 110-113 ⁰ C) : R _f = 0.26 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +1.8° (c = 0.33, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2924, 1258 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.16 (d, J = 9.0 Hz, 2 H), 7.10 (d, J = 8.5 Hz, 1 H), 6.84 (d, J = 9.0 Hz, 2 H) , 6.59 (dd, J = 8.5, 2.5 Hz, I H) , 6.51 (d, J = 2.5 Hz, I H) , 2.86 - 2.78 (m, 2 H) , 2.72 (t, J = 9.5 Hz, 1 H) , 2.29 - 2.23 (m, 2 H) , 2.12- 1.85 (m, 4 H) , 1.70 - 1.67 (m, 1 H) , 1.43 - 1.40 (m, 6 H) , 0.98 (s, 9 H) , 0.50 (s, 3 H) , 0.18 (s, 6 H) ; ¹³ C NMR δ 157.9, 153.2, 137.9, 133.3, 133.1, 129.5 (2 C) , 126.1, 119.9, 117.1, 113.1 (2 C) , 56.3,

55.2, 44.4, 44.1, 39.2, 37.7, 29.74, 29.71, 27.8,

26.3, 26.3, 25.7 (3 C) , 24.2, 21.0, 18.2, 12.7, -4.4

(2 C); HRMS (ESI-TOF) calcd for C _3I H ₄₅ O ₂ Si [M+H] ⁺ : 477.3183; found: 477.3193.

Compound 7d

Compound 7d was prepared from Styrene 6d (6.3 mg, 0.014 mmol) according to general procedure D. Purification by flash chromatography (2:1 hexanes: EtOAc) afforded 7d (4.5mg, 0.010 mmol, 72%) as a white solid (mp 168-170 ⁰ C) : R _f = 0.15 (1 : 3 EtOAc : hexanes) ; [α] ^D ₂₀ = +2.1° (c = 0.52, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1495, 1258 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 8.49 (brs, 1 H), 7.56 (d, J = 7.5 Hz, 1 H),

7.23 (brs, 1 H), 7.10 (d, J = 8.5 Hz, 1 H), 6.60 (dd, J = 8.5, 2.5Hz, 1 H) , 6.56 (d, J = 2.5 Hz , 1 H) , 2.86 - 2.80 (m, 2 H) , 2.78 (t, J = 9.5 Hz, 1 H) , 2.30 -

2.24 (m, 2 H) , 2.15 - 1.92 (m, 4 H) , 1.70 - 1.60 (m, 1 H) , 1.43 - 1.40 (m, 6 H) , 0.97 (s, 9H) , 0.53 (s, 3 H) , 0.18 (s, 6 H) ; ¹³ C NMR δ 153.3 , 150.3 , 147.5, 137.8 , 135.7, 133.0, 126.1, 119.9, 117.0, 55.3 , 54.6, 44.7 , 44.0, 39.2, 37.5, 29.7 (2 C) , 27.8 , 26.2, 25.9, 25.7 (3 C) , 24.2 , 18.2, 12.8 , 1.0, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₂₉ H ₄₂ NOSi [M+H] ⁺ : 448.3030; found: 448.3034.

Compound 7e

Compound 7e was prepared from Styrene 6e (4.3 mg, 0.008 mmol) according to general procedure D. Purification by flash chromatography (2:1 hexanes: EtOAc) afforded 7e (2.5 mg, 0.005 mmol, 58%) as a colorless oil: R _f = 0.56 (1:1 EtOAc: hexanes); [α] ^D ₂₀ = -2.0° (c = 0.10, CH ₂ Cl ₂ ); IR (neat) v _max = 2925, 2855, 1653, 1559, 1539, 1507, 1496, 1472, 1457, 1284, 1254, 947, 843 cm ^"1 ; ¹ H NMR (600 MHz, CDCl ₃ ) δ 9.22 (s, 1 H), 8.47 (d, J = 5.4 Hz, 1 H), 7.80 (s, 1 H), 7.75 (d, J = 8.4 Hz, 1 H), 7.62 (s, 1 H), 7.61 (d, J = 12.4 Hz, 1 H), 7.11 (d, J = 8.5 Hz, 1 H), 6.60 (dd, J = 8.5, 2.5 Hz, 1 H), 6.56 (d, J = 2.2 Hz, 1 H), 2.98 (t, J = 9.8 Hz, 1 H), 2.90 - 2.78 (m, 2 H), 2.34 - 2.24 (m, 3 H), 2.15 - 2.07 (m, 1 H), 2.02 - 1.94 (m, 2 H) , 1.73 (dt, J = 12.9, 2.9 Hz, 1 H) , 1.57 - 1.38 (m, 6 H), 0.97 (s, 9 H), 0.54 (s, 3 H), 0.18 (s, 6 H); ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.3, 152.3, 142.3, 140.7, 137.8, 134.6, 133.1, 132.4, 128.6, 126.1, 126.0, 125.5, 120.1, 120.0, 117.1, 57.2, 55.3, 45.1, 44.0, 39.2, 37.8, 29.7, 27.8, 26.3, 26.2, 25.7 (3 C), 24.3, 18.2, 12.9, -4.4 (2 C); HRMS

(ESI-TOF) calcd for C ₃₃ H ₄₃ NOSi [M+H] ⁺ : 498.3187; found: 498.3195.

Compound 7f

Compound 7f was prepared from Styrene 6f (10 mg, 0.022 mmol) according to general procedure D. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded 7f (9.3 mg, 0.020 mmol, 93%) as a white solid (mp 117-121 ⁰ C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes) ; [α] ^D ₂₀ = +1.6° (c = 0.37, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2928, 1508, 1253 cm ^"1 ; ¹ H NMR (400 MHz, CDCl ₃ ) δ 720 (d, J = 8.8 Hz, 1 H) , 7.19 (d, J = 8.8 Hz, 1 H) , 7.11 (d, J = 8.4Hz, 1 H) , 6.99 (d, J = 8.8 Hz, 1 H) , 6.97 (d, J = 8.8 Hz, 1 H) , 6.61 (dd, J = 8.4, 2.4 Hz, I H) , 6.57 (d, J = 2.4 Hz, I H) , 2.86 - 2.82 (m, 2 H) , 2.75 (t, J = 10.0 Hz, 1 H) , 2.24 - 2.30 (m, 2 H) , 2.10 - 1.89 (m, 4 H) , 1.67 (dd, J = 8.4, 2.4Hz, 1 H) , 1.45 - 1.42 (m, 6 H) , 0.98 (s, 9 H) , 0.50 (S, 3 H) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 161.5 (d, J _CF = 242.1 Hz) , 153.3, 137.9, 136.7 (d, J _CF = 3.1 Hz) , 133.2, 129.9 (d, J _CF = 7.5 Hz, 2 C) , 126.1, 119.9, 117.1, 114.4 (d, J _CF = 20.6 Hz, 2 C) , 56.4, 55.2, 44.4, 44.1, 39.2, 37.7, 29.7, 27.8, 26.5, 26.3, 25.7 (3 C) , 24.2, 18.2, 18.2, -4.4 (2 C) ;

HRMS (ESI-TOF) calcd for C ₃₀ H ₄₂ OFSi [M+H] ⁺ : 465.2983; found: 465.2972.

Compound 7g

Compound 7g was prepared from Styrene 6g (17 mg, 0.030 mmol) according to general procedure D. Purification by flash chromatography (15:1 hexanes: CH ₂ Cl ₂ ) afforded 7g (15.0 mg, 0.029 mmol, 96%) as a white solid (mp 129-131°C) : R _f = 0.65 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +5.1° (c = 0.71, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1497, 1327, 1123 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.54 (d, J = 8.3 Hz, 2 H) , 7.35 (d, J =

8.3 Hz, 2 H) , 7.11 (d, J = 8.5Hz, 1 H) , 6.61 (dd, J = 8.5, 2.5 Hz, 1 H) , 6.56 (d, J = 2.5 Hz, 1 H) , 2.86 - 2.82 (m, 3 H) , 2.30 - 2.25 (m, 2 H) , 2.18 - 2.12 (m, 1 H) , 2.08 - 2.00 (m, 1 H) , 1.95 - 1.90 (m, 2 H) , 1.71 - 1.68 (m, 1 H) , 1.54 - 1.40 (m, 6 H) , 0.98 (s,

9 H) , 0.51 (s, 3 H) , 0.19 (s, 6 H) ; ¹³ C NMR (125 MHz, CDCl ₃ ) δ 153.3, 145.4, 137.8, 133.1, 128.9 (2 C) , 128.3 (q, J _CF = 32.2 Hz) , 124.6 (q, J _CF = 3.8 Hz, 2C) , 121.7 (q, J _CF = 394.1 Hz) , 120.0, 117.1, 57.0, 55.4, 44.9, 44.0, 39.2, 37.7, 29.7, 26.3, 26.2, 25.7 (3 C) ,

24.2, 18.2, 12.8, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C _3I H ₄₂ OF ₃ Si [M+H] ⁺ : 515.2951; found: 515.2959.

Compound 7a-d ₂

Compound 7a-d ₂ was prepared from Styrene 6a (13 mg, 0.029 mmol) according to general procedure D, except Ra-Ni was washed with D ₂ O and isopropanol-d8 and toluene-d8 were used as solvent. Purification by flash chromatography (15:1 hexanes : CH ₂ Cl ₂ ) afforded 7a-d ₂ (12.3 mg, 0.027 mmol, 95%) as a white solid (mp

135-138°C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes) ; [α] ^D ₂₀ = +3.1° (c = 0.19, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2925, 1495, 1253 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.31-7.19 (m, 5 H), 7.11 (d, J = 8.5 Hz, 1 H) , 6.60 (dd, J = 2.5, 8.5 Hz, 1 H) , 6.55 (d, J = 2.5 Hz, 1 H) , 2.85 - 2.82 (m, 2 H) , 2.78 (t, J = 10.0 Hz, 1 H) , 2.28 - 2.24 (m, 2 H) , 2.19 - 2.12 (m, 1 H) , 2.05 - 1.87 (m, 2 H) , 1.72 - 1.70 (m, 1 H) , 1.48 - 1.42 (m, 6 H) , 0.98 (s, 9 H) , 0.51 (s, 3 H) , 0.18 (s, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.2, 141.1, 137.9, 133.3, 128.7 (2 C) , 127.7 (2 C) , 126.1, 126.0, 119.9, 57.1 (t, J _CD = 26.0 Hz) , 55.3, 44.6, 44.1, 39.2, 37.7, 29.8, 29.7, 27.9, 26.3, 25.7 (3 C) , 24.2, 23.7 (t, J _CD = 26.6 Hz) , 18.2, 12.8, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₀ D ₂ OSi [M+H] ⁺ : 449.3201; found: 449.3191.

General procedure E

To a solution of alcohol in toluene (0.01 M) , was added the suspension of Ra-Ni prepared as described above (the Ra-Ni suspension was removed by 5.75' pipette from the thick bottom layer of the vial; 1 drop suspension per 0.1 mL solution) . The reaction flask was immersed in an oil bath preheated to HO ⁰ C and stirred vigorously for 5 hours. After cooling to ambient temperature, the reaction mixture was passed through Celite, the Ra-Ni washed by CH ₂ Cl ₂ , and the combined filtrates were concentrated in vacuo. The product was purified by flash column chromatography .

Compound 9a

Compound 9a was prepared from alcohol 8a (36 mg, 0.081 mmol) according to general procedure E, Purification by flash chromatography (5:1

hexanes: CH ₂ Cl ₂ ) afforded 9a and 7a (dr = 6.6:1) as an unseperable mixture (35.0 mg, 0.080 mmol, 98%) (white solid) (mp 113-118 ⁰ C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +41.7° (c = 0.93, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1496, 1255 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.31- 7.19 (m, 3 H), 7.14-7.11 (m, 2 H), 7.01 (d, J = 8.0 Hz , I H) , 6.56 (dd, J = 8.5 , 2.5 Hz , I H) , 6.54 (d, J = 2.5 Hz, 1 H) , 3.00 (dd, J = 9.0, 1.5 Hz, 1 H) , 2.88 - 2.76 (m, 2 H) , 2.37- 2.24 (m, 1 H) , 2.11 - 1.94 (m, 5 H) , 1.55 - 1.37 (m, 6 H) , 0.99 (s, 3 H) , 0.97 (s, 9 H) , 0.62 (dt, J = 15.0, 5.0 Hz, 1 H) , 0.18 (s, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.1, 145.0, 137.8, 133.3, 128.7 (2 C) , 127.6 (2 C) , 126.1, 125.6, 119.8, 117.0, 55.8, 48.8, 45.4, 43.4, 39.3, 35.3, 29.8, 28.4, 26.4, 25.7 (3 C) , 21. 4, 18.2, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₃ OSi [M+H] ⁺ : 447.3078; found: 447.3083.

Compound 9b

Compound 9a was prepared from Alcohol 8b (12 mg, 0.026 mmol) according to general procedure E. Purification by flash chromatography (5:1 hexanes: CH ₂ Cl ₂ ) afforded 9b and 7b (dr = 26:1) as an unseperable mixture (10.3 mg, 0.023 mmol, 88%) (colorless oil) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀

= +39.6° (c = 1.14, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2928, 1496, 1288, 1256 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.10 (d, J = 8.0 Hz, 2 H), 7.03 (d, J = 8.0 Hz, 2 H), 7.02 (d, J = 8.0 Hz, 1 H), 6.56 (dd, J =8.0, 2.5 Hz, 1 H) , 6.54 (d, J = 2.5 Hz, 1 H) , 2.97 (dd, J = 8.5, 1.5 Hz, 1 H) , 2.88 - 2.77 (m, 2 H) , 2.34 (s, 3 H) , 2.56 - 2.29 (m, IH) , 2.12 - 1.89 (m, 5 H) , 1.54 - 1.38 (m, 1 H) , 0.98 (s, 3 H) , 0.97 (s, 9 H) , 0.65 (brdt, 1 H) , 0.18 (s, 6 H) ,- ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.1, 142.0, 137.8, 135.0, 133.3, 128.6, 128.3 (2X) , 126.1 (2 C) , 119.8, 117.0, 55.3, 48.8, 45.3, 39.3, 35.3, 29.8, 28.5, 28.3, 26.4, 25.7 (3 C) , 21.4, 21.0, 18.1, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₃ OSi [M+H] ⁺ : 461.3234; found: 461.3231.

Compound 9c

Compound 9c was prepared from Alcohol 8c (19 mg, 0.038 mmol) according to general procedure E. Purification by flash chromatography (5:1 hexanes: CH ₂ Cl ₂ ) afforded 9c and styrene 7c (dr = 4.2:1) as an unseperable mixture (12.0 mg, 0.025 mmol, 68%) (white solid) (mp 78-83°C) ; [α] ^D ₂₀ = +10.9° (c = 0.42, CH ₂ Cl ₂ ) ; IR (neat) V _max = 2925, 1498, 1252 cm ^"1 ; ¹ H NMR (600 MHz, CDCl ₃ ) δ 7.16 (d, J = 8.6 Hz, 2 H), 7.09-6.96 (m, 2 H), 6.84 (dd, J = 8.4, 6.0 Hz, 2

H), 6.57 - 6.53 (m, 2 H) , 3.80 (s, 3 H) , 2.95 (dd, J = 8.9, 1.5 Hz, 1 H) , 2.88 - 2.77 (ra, 2 H) , 2.35 - 2.20 (m, 2 H) , 2.11 - 2.06 (m, 1 H) , 2.02 - 1.85 (m, 3 H) , 1.69 - 1.37 (m, 6 H) , 0.98 (s, 3 H) , 0.97 (s, 9 H) , 0.65 (dt, J = 13.6, 13.3, 4.1 Hz 1 H) , 0.18 (s, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 157.6, 153.1, 137.8, 137.1, 133.3, 129.5 (2 C) , 126.1, 119.8, 113.0 (2 C) , 55.1, 54.8, 48.7, 45.3, 39.3, 35.3, 29.8, 28.6, 28.3, 25.7 (3 C) , 24.2, 21.3, 18.1, 12.7, -4.4 (2 C) ; HRMS (ESI- TOF) calcd for C _3I H ₄₄ O ₂ Si [M+H] ⁺ : 477.3183; found: 477.3181.

Compound 9d

Compound 9d was prepared from Alcohol 8d (12 mg, 0.025 mmol) according to general procedure E. Purification by flash chromatography (3:1 hexanes : EtOAc) afforded 9d and 7d (dr = 13:1) as an inseparable mixture (8.4 mg, 0.019 mmol, 72%) (white solid) (mp 82-84 ⁰ C) : R _f = 0.15 (3:1 hexanes: EtOAc) ; [α] ^D ₂₀ = +34.5° (c = 0.55, CH ₂ Cl ₂ ); IR (neat) v _max = 2931,1498, 1220 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 8.43 (brd, 2 H), 7.44 (brd, 1 H), 7.24 (brt, 1 H), 7.00 (d, J = 8.5 Hz , 1 H), 6.56 (dd, J = 8.5 , 2.0 Hz , 1 H) , 6.53 (d, J = 2.0 Hz, 1 H) , 3.00 (dd, J = 8.5, 1.5 Hz, 1 H), 2.87 - 2.76 (m, 2 H), 2.41 - 2.33 (m, 1 H), 2.13 - 1.88 (m, 5 H), 1.57 - 1.37 (m, 6 H), 1.01 (s,

3 H), 0.96 (s, 9 H), 0.59 (brdt, 1 H), 0.17 (s, 6 H); 1 ³ C NMR (150 MHz, CDCl ₃ ) δ 153.2, 150.2, 147.2, 137.7, 135.8, 133.0, 126.0, 119.8, 117.1, 53.2, 49.0, 45.5, 43.4, 39.3, 35.2, 29.7, 28.2, 28.1, 26.3, 25.7 (3 C), 25.6, 21.2, 18.2, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₂₉ H ₄₂ NOSi [M+H] ⁺ : 448.3030; found: 448.3028.

Compound 9e

Compound 9e was prepared from Alcohol 8e (5.6 mmol, 0.011 mmol) according to general procedure E. Purification by flash chromatography (2:1 hexanes: EtOAc) afforded 9e and 7e (dr = 4.3:1) as an inseparable mixture (4.1 mg, 0.007 mmol, 71%) (white solid) (mp 153-157°C) : R _f = 0.39 (3:1 hexanes : EtOAc);

[α] ^D 2o = +18.3° (c = 0.18, CH ₂ Cl ₂ ); IR (neat) v _max = 2925, 2855, 1653, 1559, 1254.0, 1284, 1254, 947, 843 cm ^'1 ; ¹ HNMR (500 MHz, CDCl ₃ ) δ 9.25 (bs, 1 H) , 8.48

(bs, 1 H) , 7.74 (d, J = 14.4 Hz, 1 H) , 7.67 (s, IH) , 7.58 - 7.54 (m, 2 H), 7.51 (d, J = 8.8 Hz, 1 H), 6.97

(d, J = 8.0 Hz, 1 H), 3.20 (d, J = 8.1 Hz, 1 H), 2.89 - 2.75 (m, 2 H), 2.48 - 2.39 (m, 1 H), 2.17 - 2.03

(m, 2 H), 2.01 - 1.88 (m, 2 H), 1.64 - 1.48 (m, 3 H), 1.48 - 1.38 (m, 2 H), 1.06 (s, 3 H), 0.95 (s, 9 H), 0.91 - 0.81 (m, 2 H), 0.58 (dd, J = 12.7, 4.1 Hz, 1 H), 0.16 (s, 6 H); ¹³ C NMR (150 MHz, CDCl ₃ ) 5153.2, 144.5, 142.3, 137.8, 134.3, 133.0, 132.8, 126.0, 125.7, 125.5, 119.8, 117.0, 55.9, 49.0, 45.8, 43.4,

39.3, 35.4 , 29.7 (2 C) , 28.4 , 28.3, 26.4 , 25.8 , 25.7 (3 C) , 21.5, 18.1, -4.4 (2 C) ; HRMS (ESI-MS) calcd for C ₃₃ H ₄₃ NOSi [M + H] ⁺ 498.3187, found 498.3195.

Compound 9a-dU

Compound 9a-d ₄ was prepared from Alcohol 8a (18 mg, 0.039 mmol) according to general procedure E, except Ra-Ni was washed with D ₂ O and toluene -d ₈ was used as solvent. Purification by flash chromatography (5:1 hexanes: CH ₂ Cl ₂ ) afforded 9a-d ₄ and 9a (dr = 10:1) as an inseparable mixture (white solid) (17.0 mg, 0.037 mmol, 96%) (mp 110-115°C) : R _f = 0.60 (1:3 CH ₂ Cl ₂ : hexanes) ; [α] ^D ₂₀ = +43.4° (c = 1.63, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1496, 1255 cm ^"1 ; ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.14 (s, 2 H), 7.02 (d, J = 8.0 Hz, 1 H) , 6.57

(dd, J = 8.5, 2.5 Hz, 1 H) , 6.54 (d, J = 2.5 Hz, 1 H) , 2.88 - 2.77 (m, 2 H) , 2.36 - 2.34 (m, 1 H) , 2.11 - 1.94 (m, 5 H) , 1.55 - 1.37 (m, 6 H) , 1.00 (s, 3 H) , 0.98 (s, 9 H) , 0.63 (dt, J = 15.0, 5.0 Hz, 1 H) , 0.19 (S, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.1, 145.0, 137.8, 133.3, 128.7, 127.5 (t, J _CD = 32.0 Hz, 2 C) , 126.1 (2 C) , 125.4 (t, J _CD = 24.3 Hz) , 119.8, 117.0, 55.3 (t, JCD = 26.6 Hz) , 48.9, 45.3, 43.4,

39.3, 35.3, 29.8, 28.4, 26.4, 25.7 (3 C) , 21. 4,

18.2, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₃₉ D ₄ OSi

[M+H] ⁺ : 451.3325; found: 451.3320.

Compound 9a-d, ₃

Compound 9a-d was prepared from Compound 9a (14 mg, 0.031 mmol) according to general procedure E, except Ra-Ni was washed with D ₂ O and toluene-d8 was used as solvent. Purification by preparative TLC (10: 1 hexanes: CH ₂ Cl ₂ ) afforded Compound 9a-d ₃ (dr = 10:1) and its diasteroisomer as an inseparable mixture (10 mg, 0.023 mmol, 75%) (white foam) : Rt = 0.60 (1:3 CH ₂ Cl ₂ : hexanes ) ; [α] ^D ₂₀ = +45.8° (c = 0.31, CH ₂ Cl ₂ ) ; IR (neat) v _max = 2930, 1496, 1255 cm ^"1 ; ¹ H NMR (600 MHz, CDCl ₃ ) δ 7.14 (s, 2 H), 7.02 (d, J = 8.0 Hz, I H) , 6.57 (dd, J = 8.5 , 2.5 Hz , I H) , 6.54 (d, J = 2.5 Hz, 1 H) , 3.00 (dd, J = 9.0, 1.5 Hz, 1 H) , 2.88 - 2.77 (m, 2 H) , 2.36 - 2.34 (m, 1 H) , 2.11 - 1.94 (m, 5 H) , 1.55 - 1.37 (m, 6 H) , 1.00 (s, 3 H) , 0.98 (s, 9 H) , 0.63 (dt, J = 15.0, 5.0 Hz, I H) , 0.19 (s, 6 H) ; ¹³ C NMR (150 MHz, CDCl ₃ ) δ 153.1, 145.0, 137.8, 133.3, 128.7, 127.5 (t, J _CD = 32.0 Hz, 2 C) , 126.1 (2 C) , 125.4 (t, J _C D = 24.3 Hz) , 119.8, 117.0, 55.3, 48.9, 45.3, 43.4, 39.3, 35.3, 29.8, 28.4, 26.4, 25.7

(3 C) , 21. 4 , 18.2, -4.4 (2 C) ; HRMS (ESI-TOF) calcd for C ₃₀ H ₄₀ D ₃ OSi [M+H] ⁺ : 450.3263 ; found: 450.3251.

17-epi-cortistatin A (4)

To cortistatinone (3) (5 mg, 0.014 mmol, 1.0 equiv) in CH ₂ Cl ₂ (1.4 mL, 0.001 M) was added TMSimidazole (5.8 mg, 6.1 μl, 0.042 mmol, 3.0 equiv) . After 5 hours, the reaction mixture so formed was diluted with CH ₂ Cl ₂ (10 mL) and washed with sat. aq. NaHCO ₃ (10 mL) . The aqueous layer was extracted with CH ₂ Cl ₂ (4 x 10 mL) and these portions were added to the organic layer, dried over MgSO ₄ , filtered, and concentrated in vacuo. The residue was purified by chromatography (EtOAc) and then dissolved into THF (28 μl, 0.5 M) (solution A) .

To 7-bromoisoquinoline (8.6 mg, 0.042 mmol, 3.0 eqiv.) in THF (0.21 mL, 0.2 M) was added n-BuLi (17 μL, 2.5 M, 0.042 mmol, 3.0 equiv) dropwise at -78

⁰ C. After 40 minutes, TMEDA was added (19 μL, 0.13 mmol, 9.0 equiv) . After 10 minutes more, solution A was added into the reaction mixture. After another 10 minutes, the reaction was quenched with sat. aq. NaHCO ₃ (10 mL) . The aqueous layer was extracted with EtOAc (4 x 10 mL) . The combined organics were dried

with MgSO ₄ , filtered, and concentrated in vacuo. The residue was dissolved in 1% EtOH in toluene (2.8 ml, 0.005 M) and Ra-Ni (prepared by procedure above, 28 drops) was added to form a reaction mixture.

The vessel containing the reaction mixture was immersed in an oil bath preheated to 110 ⁰ C, and the reaction mixture stirred vigorously for 30 minutes, at which point the reaction had progressed to approximately 70% conversion, as judged by LCMS. Removal of the supernatant, followed by washing of the Raney nickel catalyst with 1:1 MeOH: EtOAc (10 mL) , and concentration of the combined filtrates produced a residue that was stirred in 10% aq. AcOH (1 mL) for 10 minutes and concentrated in vacuo. The residue was then purified by HPLC, yielding 11-epi- cortistatin A (4) (1.1 mg, 0.002 mmol, 16%) as a colorless oil and cortistatin A (1) (0.3 mg, 0.0006 mmol, 5%) as a white solid. 17-epi-Cortistatin A: [α] ^D ₂₀ = +45.5° (c = 0.068, CD ₃ OD); IR (neat) v _max = 3355, 3039, 1679, 1295, 1202, 897, 887 cm ^"1 ; ¹ HNMR (600 MHz, CDCl ₃ ) δ 9.27 (s, 1 H), 8.32 (d, J = 6.0 Hz, 1 H) , 7.95 - 7.85 (m, 3 H) , 7.69 (d, J = 8.1 Hz ₁ I H) , 6.01 (d, J = 2.4 Hz, 1 H), 5.15 (dd, J = 5.1. 2.5 Hz, 1 H), 3.9 (d, J = 9.0 Hz, 1 H), 3.36 (t, J = 9.8 Hz, 1 H), 3.28 - 3.25 (m, 1 H), 3.12 (t, J = 7.2 Hz, 1 H), 2.84 (s, 3 H), 2.69 (s, 3 H) , 2.50 - 2.44 (m, 1 H), 2.40 - 2.31 (m, 2 H), 2.18 - 2.16 (m, 1 H), 2.11 - 2.03 (m, 3 H), 1.95 - 1.88 (m, 3 H), 1.75 - 1.64 (m, 3 H), 1.04 (s, 3 H); HRMS (ESI-MS) calcd for C ₃₀ H ₃₆ N ₂ O ₃ [M + H] ⁺ 473.2799, found 473.2786.

Each of the patents, patent applications and articles cited herein is incorporated by reference. The use of the article "a" or "an" is intended to include one or more.

The foregoing description and the examples are intended as illustrative and are not to be taken as limiting. Still other variations within the spirit and scope of this invention are possible and will readily present themselves to those skilled in the art.