Cu-Guanidine-Catalysed Asymmetric Protoboration of Internal 1,3-Dienes for One-Pot Access to Chiral Homoallylic Alcohols

Abstract

The enantioselective protoboration of acyclic internal 1,3-dienes under mild conditions is achieved with a copper-guanidine catalyst. This protocol furnishes α-stereogenic Z-allyl boronates and enables one-pot crotylboration with aldehydes to afford chiral homoallylic alcohols. The stereochemical influence of C=C bond geometry and substituent positioning is also elucidated.