Copper-Catalyzed 2,2,2-Trifluoroethylthiolation of Aryl Halides

Herein, a copper-catalyzed 2,2,2-trifluoroethylthiolation reaction of aryl bromides and iodides with elemental sulfur, and 1,1,1-trifluoro-2-iodoethane is described. The reaction showed excellent functional group tolerance and allowed the synthesis of various substituted aryl 2,2,2-trifluoroethyl thioethers with good to excellent yields. This transformation constitutes a one-pot synthesis of 2,2,2-trifluoroethylthiolated compounds from inexpensive, readily available starting materials. Utility of the protocol was further demonstrated in the late-stage synthesis of the pirfenidone derivative. The copper thiolate species were prepared and proposed as key intermediates in the catalytic cycle.