Asymmetric Hetero-Ene Reactions of Trimethylsilyl Enol Ethers Catalyzed by Tridentate Schiff Base Chromium(III) Complexes

Abstract

A concerted ene reaction between silyl enol ethers and simple aldehydes is catalyzed by chiral (Schiff base) CrIII complexes with high stereoselectivity (see scheme). This method leads directly to enantioenriched β-hydroxy silyl enol ether derivatives, which are known to be useful intermediates for the stereocontrolled synthesis of substituted polyol frameworks.