ELECTROCHEMICAL HYDROTRIFLUOROMETHYLATION OF FUMARONITRILE

Electrooxidation of trifluoroacetic acid in the presence of fumaronitrile (1) in an MeCN-H2O-(Pt) system provides 2-(trifluoromethyl)succinonitrile (2) in a 65% yield. The electrochemical reaction is remarkably affected by the reaction temperature. That is, at the ice-cooling temperature, a simple hydrogenation of 1 predominates, while at 50–55 °C, the desired hydrotrifluoromethylation proceeds exclusively. The anodically generated tri-fluoromethyl radicals recombine with the succinonitrile radicals produced at the cathode, leading to the formation of 2. © 1990, American Chemical Society. All rights reserved.