Self-[3+2] annulation reaction of pyridinium salts: synthesis of N-indolizine-substituted pyridine-2(1H)-ones

Abstract

A self-[3+2] annulation reaction of pyridinium salts has been developed for the synthesis of N-indolizine-substituted pyridine-2(1H)-ones. This protocol was carried out under mild reaction conditions without any precious catalysts in generally moderate to good yields. Additionally, a plausible mechanism for the transformation was proposed.