Facile synthesis of α,α-difluoroalkyl aryl thioethers and their oxidative desulfurization–fluorination to trifluorides

Alkyl 2-arylthio-2,2-difluoroacetates are synthesized in 52–77% yield from alkyl 2-(arylthio)acetates via two succeeding fluoro-Pummerer rearrangements using the reagents combination of N-haloimides as electrophiles and excess Py·9HF as the fluoride source at room temperature. Subsequent treatment of the formed fluorinated thioethers with the same reagents at elevated temperature gave alkyl trifluoroacetates in almost quantitative yield under optimised conditions by oxidative desulfurization–fluorination.