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Versatile Homoallylic Boronates by Chemo-, SN 2'-, Diastereo- and Enantioselective Catalytic Sequence of Cu-H Addition to Vinyl-B(pin)/Allylic Substitution.

ABSTRACT: A highly chemo-, diastereo- and enantioselective catalytic method that efficiently combines a silyl hydride, vinyl-B(pin) (pin=pinacolato) and (E)-1,2-disubstituted allylic phosphates is introduced. Reactions, best promoted by a Cu-based complex with a chiral sulfonate-containing N-heterocyclic carbene, are broadly applicable. Aryl-, heteroaryl-, alkenyl-, alkynyl- and alkyl-substituted allylic phosphates may thus be converted to the corresponding homoallylic boronates and then alcohols (after C-B bond oxidation) in 46-91?% yield and in up to >98?% SN 2':SN 2 ratio, 96:4 diastereomeric ratio and 98:2 enantiomeric ratio. The reasons why an NHC-Cu catalyst is uniquely effective (vs. the corresponding phosphine systems) and the basis for different trends in stereoselectivity are provided with the aid of DFT calculations.

SUBMITTER: Lee J

PROVIDER: S-EPMC5267969 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Versatile Homoallylic Boronates by Chemo-, S<sub>N</sub> 2'-, Diastereo- and Enantioselective Catalytic Sequence of Cu-H Addition to Vinyl-B(pin)/Allylic Substitution.

Lee Jaehee J Torker Sebastian S Hoveyda Amir H AH

Angewandte Chemie (International ed. in English) 20161220 3

A highly chemo-, diastereo- and enantioselective catalytic method that efficiently combines a silyl hydride, vinyl-B(pin) (pin=pinacolato) and (E)-1,2-disubstituted allylic phosphates is introduced. Reactions, best promoted by a Cu-based complex with a chiral sulfonate-containing N-heterocyclic carbene, are broadly applicable. Aryl-, heteroaryl-, alkenyl-, alkynyl- and alkyl-substituted allylic phosphates may thus be converted to the corresponding homoallylic boronates and then alcohols (after C ...[more]

PMID: 27996213

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