Photocatalyst‐Free, Visible Light‐Driven 6π‐Photocyclization: A Facile Access to Multisubstituted Cyanodihydropyrroles and Cyanopyrroles

A visible‐light‐driven, photocatalyst‐free 6π‐photocyclization of N ‐substituted dieneamines has been developed. Various polysubstituted cyanodihydropyrroles and cyanopyrroles were constructed in good‐to‐excellent yields under nitrogen or air atmosphere. This novel strategy features formal hydroalkenylation, divergent synthesis, excellent regioselectivity, wide functional group tolerance, and operational convenience. Mechanistic studies suggest that both the 1,4‐H shift of the diradical intermediate and the deprotonation/protonation processes may be involved in the transformation.