Visible-Light-InducedTrifluoromethyl Radical Additionto Thiocarbonyl of Thioamide Derivatives

An effective trifluoromethyl radical addition to the thiocarbonyl of thioamide derivatives is described, which produces various trifluoromethylthiolated <i>N</i>-heterocycles such as 6-(trifluoromethylthio)phenanthridine, 2-(trifluoromethylthio)indole, and 2-(trifluoromethylthio)benzothiazole derivatives under visible-light irradiation. The process features advantages such as mild reaction conditions, a cheap and easily available trifluoromethyl source (CF₃Br), and green energy, as well as broad substrate scope. The reaction mechanism is investigated in detail, and scale-up experiments are performed.