Asymmetric synthesis using chirally modified borohydrides. Part 2. Enantioselective reduction of ketones with polymeric (S)-prolinol–borane reagent

Abstract

Chiral polymeric reagents have been prepared from polymeric (S)-prplinols and borane and used in the enantioselective reduction of a series of prochiral ketones under various conditions. Reductions with these polymeric reagents are shown to give alcohols of reasonably good optical purity (up to 80%). The results are compared to those obtained with (S)-N-benzylprolinol–borane complex which is a soluble model reagent.