Electrophilic trifluoromethylthiolation of thiols with trifluoromethanesulfenamide

The highly selective and effective, metal-free, acid promoted trifluoromethylthiolation of thiols to the corresponding trifluoromethyl disulfides is described. The aryl-, benzyl-, aliphatic-, and heteroaromatic thiols reacted selectively, thus proving excellent reaction generality. The method offers practical and easy access to the previously mostly unknown or rarely reported trifluoromethyl disulfides. Comparison of the relative reactivity of thiophenols suggests formation of an electron-deficient intermediate in the transition state, which was supported by quantum chemical calculations. The supposed reaction course is discussed.