A Bispidine-Based Chiral Amine Catalyst for Asymmetric Mannich Reaction of Ketones with Isatin Ketimines
Gonglin Li, Mohuizi Liu, Sijia Zou, Xiaoming Feng, Lili Lin
Abstract
A unique chiral amine organocatalyst with a bispidine structure was found to be efficient for the diastereo- and enantioselective Mannich reaction of isatin ketimines with ketones. A series of 3-substituted 3-amino-2-oxindoles bearing vicinal tertiary and quaternary chiral stereogenic centers were obtained in excellent yields with excellent dr and ee values. The gram-scale synthesis and transformation of the product showed the practicability of this methodology. In addition, a possible transition state model was proposed to explain the origin of the stereoselectivity.
Topics & Concepts
StereocenterChemistryIsatinVicinalEnantioselective synthesisMannich reactionAmine gas treatingCatalysisStereoselectivityOrganic chemistryOrganocatalysisCombinatorial chemistryAsymmetric Synthesis and CatalysisSynthesis and Catalytic ReactionsAsymmetric Hydrogenation and Catalysis