Catalytic asymmetric Mukaiyama aldol reactions in aqueous media

Abstract

Chiral copper(II)-catalyzed asymmetric aldol reactions of silyl enol ethers with aldehydes (the Mukaiyama aldol reaction) have been performed in an ethanol-water solution. The use of the protic solvent including water is a key to achieve these reactions. Moreover, a catalytic asymmetric aldol reaction in pure water without using organic solvents has also been successfully carried out. This report has proposed and demonstrated a new concept for solvents in catalytic asymmetric aldol reactions.