anti-Selective Direct Asymmetric Mannich Reactions Catalyzed by Axially Chiral Amino Sulfonamide as an Organocatalyst

A direct asymmetric Mannich reaction using a novel axially chiral amino trifluoromethanesulfonamide (S)-3 has been developed in highly anti-selective and enantioselective manners. Thus, in the presence of a catalytic amount of (S)-3, the reactions between aldehydes and the α-imino ester 4 proceed smoothly to give the functional β-amino aldehydes with significantly higher anti/syn ratio and enantioselectivity than previously possible.