Accelerating Amine‐Catalyzed Asymmetric Reactions by Intermolecular Cooperative Thiourea/Oxime Hydrogen‐Bond Catalysis

Abstract

AbstractThe ability of intermolecular cooperative thiourea/oxime hydrogen‐bond catalysis for improving and accelerating asymmetric aminocatalysis is presented. The two readily available hydrogen‐bond‐donating catalysts operates in synergy with a chiral amine catalyst to accomplish highly stereoselective transformations. The synergistic catalyst systems simultaneously activate both electrophiles and nucleophiles, and make the transformations more chemo‐ and stereoselective. This was exemplified by performing co‐catalytic enantioselective direct intermolecular α‐alkylation reactions of aldehydes, direct aldol reactions, and asymmetric conjugate reactions, which gave the corresponding products in high yields and enantiomeric ratios.