Ion-radical perfluoroalkylation. Part 11. Perfluoroalkylation of thiols by perfluoroalkyl iodides in the absence of initiators

Abstract Perfluoroalkylation of aliphatic, aromatic and heterocyclic thiols by perfluoroalkyl iodides in the presence of Et 3N appears to occur spontaneously under daylight or the usual laboratory lighting conditions at 20–22 °C and is complete in 10–15 min to 2–3 h. An exception to this rule are thiols with a low nucleophilicity. The reaction is accompanied by thiol oxidation (2%–3%) and depends directly on the temperature, lighting, solvent polarity and electronic properties of the perfluoroalkylating agents and of the thiol substituents. At the same time, formation of diaryl disulphides frequently occurs contrary to above rules. The reaction mechanism is discussed.