Accessing pyrrolo[1,2- a ]indole derivatives via visible-light-induced dearomatizative cyclization of indoles.

Pyrrolo[1,2- a ]indoles are structurally important scaffolds in many natural products and bioactive compounds. Herein, we report a novel synthetic method for pyrrolo[1,2- a ]indole derivatives through visible-light-induced cascade dearomatizative cyclization of indoles with external nucleophiles. Moderate yields, good diastereoselectivities, and excellent regioselectivities were generally observed with the resultant indole-fused polycyclic compounds.