A visible-light-induced intermolecular [3 + 2] alkenylation–cyclization strategy: metal-free construction of pyrrolo[2,1,5-cd]indolizine rings

Abstract

A simple and efficient visible-light-induced intermolecular [3 + 2] alkenylation–cyclization process has been developed. This reaction provided an unprecedented metal-free double C(sp²)–H bond oxidation coupling of indolizines with electron-deficient alkenes. Through this cascade reaction, a series of pyrrolo[2,1,5-cd]indolizine derivatives with a large π-system were synthesized. Furthermore, this approach features easily available starting materials, good functional group tolerance, step-economy, high efficiency and mild conditions.