Direct Asymmetric Mannich Reaction Catalyzed by a d-Glucosamine-Derived Organocatalyst

Abstract

Sugar-based primary amines have been employed as organocatalysts for the direct asymmetric Mannich reaction. By catalyst-screening experiments, we observed that catalysts bearing a hydroxy function at C-3 actively participated in the reaction, possibly through hydrogen bonding with the imine generated in situ, to provide β-amino carbonyl compounds with better diastereoselectivity and enantioselectivity. All the products were obtained in good to excellent enantiomeric excess.