Chiral Lewis Acid Catalysis in Aqueous Media* Catalytic Asymmetric Aidol TReactions of Silyl Enol Ethers with Aldehydes in a Protic Solvent Including Water

Chiral coppcr(II)-catalyzed asymmetric aldol reactions of silyl enol ethers with aldehydes have been successfully carried out in a water-ethanol solution. The use of the protic solvent including water is essential in these reactions, and this report has proposed and demonstrated a new concept for solvents in eatalytic asymmetric aldol reactions,