title: Chiral ammonium betaines: a bifunctional organic base catalyst for asymmetric Mannich-type reaction of alpha-nitrocarboxylates.
abstract: 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.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Uraguchi
authors.forename: Kyohei
authors.initials: K
authors.lastname: Koshimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Ooi