Electrochemical reduction of fluorinated aromatic carboxylic acids

Abstract

Pentafluorobenzoic acid has been selectively electrochemically reduced in good yield to 2,3,5,6-tetrafluorobenzoic acid, 2,3,5,6-tetrafluorobenzyl alcohol, and pentafluorobenzyl alcohol. Electrochemical reduction of 4-chloro-, 4-amino-, 4-methoxy-, and 4-hydro-tetrafluorobenzoic acids, pentafluorobenzaldehyde, ethylpentafluorobenzoate, and pentafluorobenzamide has been studied. The mechanism of the reduction process, and therefore the products obtained, is governed by the potential of the cathode, the acidity, and the type of ions present in the base electrolyte.