Synthesis and Reactivity of Trifluorodithioacetates Derived from Trifluorothioacetamides.

A general synthesis of trifluorodithioacetates is described by thiolysis of trifluorothioamidium salts, derived from trifluorothioacetamides. The reactivity of these CF3 bearing C-2 building blocks has been investigated towards nucleophiles and in cycloaddition reactions. Trifluorodithioacetates react with dienes to give thiopyrans and with diazo compounds to give trifluoromethyl vinyl sulphides via thiirane intermediates. With amines, trifluorodithioacetates give rise to trifluorothioacetamides while thiols add by thiophilic attack leading to new trifluoroethane dithioacetal disulphide. Two equivalents of phosphite furnish one equivalent of thiophosphate and one of phosphorylated trifluoroethane.