Multi-step reactions of N-monosubstituted (polyfluoroalkane)thioamides with alkyllithium reagents

Reactions of N-alkyl- or N-aryl(perfluoroalkyl)thiocarboxamides with alkyl lithium reagents are described. Trifluorothioacetamides are converted into the corresponding lithium salts. Compounds bearing a long polyfluorinated chain terminated by a CHF2 group and compounds containing an N-alkyl substituent with a proton adjacent to nitrogen react further via a multi-step reaction sequence involving HF elimination and then vinylic fluorine substitution and/or SN′ type fluorine substitution. These transformations led to unsaturated N-monosubstituted polyfluorinated thioamides.