Asymmetric Phase-Transfer-Catalyzed Conjugate Addition of Glycine Imine to Exocyclic α,β-Unsaturated Ketones: Construction of Polycyclic Imines Containing Three Stereocenters
摘要:
We developed a facile, one-pot, multistep transformation between glycine imine and exocyclic alpha,beta-unsaturated ketones in reactions catalyzed by chiral phase-transfer catalysts (PTC). A series of polycyclic imines containing three adjacent stereocenters were obtained in good to high yields with high diastereo- and enantioselectivities. Further transformation of the imines could afford N-fused polycyclic compounds with four adjacent stereocenters.