Visible-light-driven photochemical Cadogan-type cyclization has been discovered. The organic D-A type photosensitizer 4CzIPN found to be an efficient mediator to transfer energy from photons to the transient intermediate that breaks the barriers of deoxygenation in Cadogan reaction and enables a mild metal-free access to carbazoles and related heterocycles. DFT calculation results indicate mildly endergonic formation of the intermediate complex of nitrobiarenes and PPh₃, which corresponds with experimental findings regarding reaction temperature. The robust synthetic capacity of the photoredox Cadogan reaction systems has been demonstrated by the viable productivity of a broad range of carbazoles and related N-heterocycles with good tolerance of various functionalities.

已发现可见光驱动的光化学卡多根型环化。发现有机 DA 型光敏剂 4CzIPN 是将能量从光子转移到瞬态中间体的有效介质，该中间体打破了卡多根反应中的脱氧壁垒，并使无温和金属的咔唑和相关杂环成为可能。DFT 计算结果表明硝基双芳烃和 PPh ₃的中间体复合物的温和吸能形成，这与关于反应温度的实验结果一致。光氧化还原 Cadogan 反应系统的强大合成能力已通过广泛范围的咔唑和相关N-杂环的可行生产力得到证明，这些N-杂环对各种官能团具有良好的耐受性。