A designer axially chiral amino sulfonamide as an efficient organocatalyst for direct asymmetric mannich reactions of N-Boc-protected imines.
The moderate nucleophilicity of the axially chiral amino sulfonamide (S)-1 suppresses the problematic side reactions, including aldol reactions, in the asymmetric Mannich reaction of N-Boc-protected imines with aldehydes. The corresponding adducts are obtained in good yield and excellent stereoselectivity (see scheme; Boc = tert-butoxycarbonyl, Tf = trifluoromethanesulfonyl).
Kano
Taichi
T
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Yamaguchi
Yukako
Y
Maruoka
Keiji
K
D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D007097:Imines / Q000138:chemical synthesis / Q000737:chemistry*; D008352:Mannich Bases / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D013237:Stereoisomerism; D013449:Sulfonamides / Q000138:chemical synthesis / Q000737:chemistry*
D000447:Aldehydes; D007097:Imines; D008352:Mannich Bases; D013449:Sulfonamides; D009584:Nitrogen