Highly regioselective anodic monofluorination of various aryl and alkyl fluoroalkyl sulfides was successfully carried out, and fluorine was exclusively (aryl sulfides) or preferentially (alkyl sulfides) introduced at the position alpha to the fluoroalkyl group. Even simple alkyl phenyl sulfides devoid of an electron-withdrawing group could be anodically monofluorinated in satisfactory yields for the first time when etheral solvents were used as an electrolytic solution. A unique Pummerer-type mechanism uta fluorosulfonium ions was proposed for this anodic fluorination by comparison with anodic alpha-methoxylation previously studied.
Fuchigami Toshio, Konno Akinori, Nakagawa Kiyono, Shimojo Moriyasu, J. Org. Chem, 59 (1994) N 20, S 5937-5941