Preparation of Trifluoromethyl Aryl Sulfides Using Silver(I) Trifluoromethanethiolate and an Inorganic Iodide

Reaction of silver(I) trifluoromethanethiolate (AgSCF(3)) with KI or tetra-n-butylammonium iodide in acetonitrile leads to the formation of a nucleophilic source of trifluoromethanethiolate. This source is capable of converting activated fluoro-, chloro-, bromo-, and iodoaromatics into the corresponding trifluoromethyl aryl sulfides under mild conditions. After successful reaction with tetra-n-butylammonium iodide, crystals of Bu(4)N[Ag(3)I(4)] precipitate from the reaction mixture. With less activated aromatic compounds, decomposition of the trifluoromethanethiolate anion occurs preferentially, giving bis(trifluoromethyl)disulfide, tetrakis(trifluoromethylthio)ethene, and 3,4,5, 6-tetrakis(trifluoromethylthio)-1,2-dithiine. The use of copper(I) trifluoromethanethiolate and mercury(II) trifluoromethanethiolate for such reactions has also been investigated.