A Selective Transformation of Enals into Chiral γ-Amino Alcohols

A one-pot synthesis of chiral amino alcohols from alpha,beta-unsaturated aldehydes is reported which circumvents competitive 1,2-versus 1,4-boryl addition, by means of using a sterically hindered amine-derived imine. In addition to the complete chemoselectivity, modification of the Cu(I) catalyst with readily available chiral diphosphines, such as (R)-DM-BINAP, gave the 1,4-boryl addition products with high levels of asymmetric induction.