Visible‐Light Induced Cyclization to Carbazole‐Fused Eight‐Membered Diazocan‐5‐ones

Herein, a novel visible‐light‐induced sulfonylation cyclization for the facile construction of challenging carbazole‐fused eight‐membered N‐heterocycles has been described for the first time under additive‐, base‐, and external photosensitizer‐free conditions. Mild reaction conditions, good functional group compatibility, and scalability reaction demonstrate the potential for further industrial application. A radical route was proposed based on radical inhibition experiments, visible‐light irradiation on‐off test, AQE calculation and fluorescence quenching studies.