Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry & University of Chinese Academy of Sciences, The Chinese Academy of Sciences, Beijing 100190, P. R. China.
School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
J Org Chem. 2020 Jul 17;85(14):9080-9087. doi: 10.1021/acs.joc.0c01000. Epub 2020 Jul 7.
By combining "-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 "-centered succinimidyl radical," which was responsible for the cleavage of the benzylic C-H bond, relying on the reducing ability of Acr-Mes.
通过将安全的氯源“-氯代丁二酰亚胺 (NCS)”与光催化剂“Acr-Mes”结合，我们成功地在可见光照射下实现了苄位 C-H 键的氯化。此外，通过添加甲醇钠，苄基氯化物可以在一锅法中顺利转化为苄基醚。这种温和且可扩展的氯化方法对各种甲苯衍生物都有效，特别是对缺电子的底物。仔细的机理研究表明，NCS 提供了一个氢供体“-中心琥珀酰亚胺基自由基”，它负责苄位 C-H 键的断裂，这依赖于 Acr-Mes 的还原能力。
