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A Designer Axially Chiral Amino Sulfonamide as an Efficient Organocatalyst for Direct Asymmetric Mannich Reactions of N-Boc-Protected Imines

Authors


  • This work was partially supported by a Grant-in-Aid for Scientific Research on Priority Areas “Advanced Molecular Transformation of Carbon Resources” from the Ministry of Education, Culture, Sports, Science, and Technology (Japan). Y.Y. is grateful to the Japan Society for the Promotion of Science for Young Scientists for a research fellowship.

Abstract

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).

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