Construction of Quaternary Stereogenic Carbon Centers through Copper-Catalyzed Enantioselective Allylic Cross-Coupling with Alkylboranes

Authors


  • This work was supported by Grants-in-Aid for Young Scientists (A) and Challenging Exploratory Research, JSPS, to H.O. and by CREST and ACT-C, JST, to M.S.

Abstract

A combination of an in situ generated chiral CuI/DTBM-MeO-BIPHEP catalyst system and EtOK enabled the enantioselective SN2′-type allylic cross-coupling between alkylborane reagents and γ,γ-disubstituted primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having three sp3-alkyl groups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross-coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed.

Ancillary