화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.130, No.33, 10878-10878, 2008
Chiral ammonium betaines: A bifunctional organic base catalyst for asymmetric Mannich-type reaction of alpha-nitrocarboxylates
A chiral ammonium betaine, an intramolecular ion-pairing quaternary ammonium aryloxide 3, has been designed and its vast potential as an enantioselective organic base catalyst has been successfully demonstrated in the highly enantioselective direct Mannich-type reaction of alpha-substituted alpha-nitrocarboxylates 2 with various N-Boc imines 1. The present study provides a conceptually new approach toward the design of bifunctional, chiral quaternary ammonium salts and their utilizations as a homogeneous organic molecular catalyst.