Iron‐Catalyzed Radical Carbamoylation/Annulation Cascade via Visible‐Light‐Induced Ligand‐to‐Metal Charge Transfer

A visible‐light‐promoted strategy is developed for the synthesis of indolo[2,1‐ a ]isoquinolin‐6(5 H )‐one scaffolds under ambient conditions. This protocol leverages photoinduced iron LMCT catalysis to generate carbamoyl radicals from a broad range of substituted oxamic acids, thereby facilitating a cascade radical addition‐cyclization sequence. The reaction proceeds under photosensitizer‐free conditions, offering good to excellent yields, broad functional group tolerance, and operational simplicity. Detailed mechanistic investigations indicate the involvement of a radical pathway in this catalytic transformation.