Catalyst- and Metal-Free Photo-Oxidative Coupling of Thiols with BrCCl₃

This paper reported a catalyst- and metal-free method to construct disulfide bond with BrCCl₃ under light irradiation. This clean and mild reaction promoted the oxidative coupling of thiols with wide substrate scope, and is applicable to benzylic, aryl and aliphatic thiols, especially cysteine derivative. The disulfides were obtained in high yields up to 98 %, avoiding the use of heating, strong oxidant, metal reagent or catalyst. This facile strategy will facilitate the synthesis of disulfide compounds.