Visible Light-Catalyzed Benzylic C–H Bond Chlorination by a Combination of Organic Dye (Acr<sup>+</sup>-Mes) and <i>N</i>-Chlorosuccinimide
Ming Xiang, Chao Zhou, Xiu‐Long Yang, Bin Chen, Chen‐Ho Tung, Li‐Zhu Wu
Abstract
By combining “N-chlorosuccinimide (NCS)” as the safe chlorine source with “Acr+-Mes” as the photocatalyst, we successfully achieved benzylic C–H bond chlorination under visible light irradiation. Furthermore, benzylic chlorides could be converted to benzylic ethers smoothly in a one-pot manner by adding sodium methoxide. This mild and scalable chlorination method worked effectively for diverse toluene derivatives, especially for electron-deficient substrates. Careful mechanistic studies supported that NCS provided a hydrogen abstractor “N-centered succinimidyl radical,” which was responsible for the cleavage of the benzylic C–H bond, relying on the reducing ability of Acr•-Mes.