Fe2O3-Promoted Intermolecular Chlorotrifluoromethylthiolation of Alkenes.

A simple, convenient method for intermolecular chlorotrifluoromethylthiolation of alkenes by using a low-cost and more abundant iron catalyst has been developed. This protocol provides a straightforward way to synthesize a variety of useful SCF3-containing chlorides from a wide range of alkenes, including electron-deficient, aromatic, and unactivated alkenes. Mechanistic studies indicate that this is a free radical transformation, and the stronger electrophilic trifluoromethylthiolating reagent CF3SCl was generated in situ under the employed conditions. The synthetic applications of this approach were also explored by a variety of synthetically useful transformations.