Indolizine synthesis via radical cyclization and demethylation of sulfoxonium ylides and 2-(pyridin-2-yl)acetate derivatives

Abstract

A novel radical cross-coupling/cyclization of 2-(pyridin-2-yl)acetate derivatives and sulfoxonium ylides is developed, which provides a straightforward access to structurally diverse methylthio-substituted indolizine. A series of 1,2,3-trisubstituted indolizines are readily synthesized in modest yields. In this process, sulfoxonium ylides undergo disproportionation and produce a type of indolizine derivative which has not been seen before. This route reveals a novel discovery that DMSO does not drop off from sulfoxonium ylides.