Asymmetric Phase-Transfer-Catalyzed Conjugate Addition of Glycine Imine to Exocyclic α,β-Unsaturated Ketones: Construction of Polycyclic Imines Containing Three Stereocenters

We developed a facile, one-pot, multistep transformation
between glycine imine and exocyclic α,β-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.