Domino nucleophilic trifluoromethylations of alkyl perfluorodithioesters

Under nucleophilic initiation, alkyl perfluorodithioesters react with trifluoromethyl(trimethyl)silane in a domino process beginning with a thiophilic addition-β-elimination of fluoride ion which leads to a perfluoroketenedithioacetal. Further addition–elimination steps eventually gives a mixture of mono, bis- and tris(trifluoromethyl) vinyl sulfides. Although they are difficult to separate, these new compounds were fully characterized by 19F NMR and mass spectrometry.