Intramolecular Pyridine Activation - Dearomatization Reaction: Highly Stereoselective Synthesis of Polysubstituted Indolizidines and Quinolizidines

An unprecedented intramolecular pyridine activation-asymmetric dearomatization reaction is described. This process produces 5-substituted indolizidines and 6-substituted quinolizidines In excellent yields and in a highly regio- and diastereoselective fashion. Formal syntheses of trans-indolizidine alkaloids are presented along with some preliminary results in the formation of C-5 quaternary centers.