Electrochemical Reduction of Cinnamonitrile in the Presence of Carbon Dioxide: Synthesis of Cyano- and Phenyl-Substituted Propionic Acids

Abstract

Cyano- and phenyl-substituted propionic acids were synthesized simply and efficiently by electrocarboxylation of cinnamonitrile in undivided cells using the non-noble metal nickel as cathode and magnesium as the anode. The radical anion generated by the electroreduction of cinnamonitrile in the absence of CO2 is involved in several competitive reactions that lead to the formation of linear hydrodimers, cyclic hydrodimers, saturated dihydro products, and glutaronitrile derivatives. While under 101.325 kPa of CO2, the electrocarboxylation could easily be carried out in the absence of additional catalysts, and with good yield (84.8%). The influence of various synthetic parameters, such as the nature of the electrode, the working potential, the concentration, and the temperature, on the electrocarboxylation reaction was investigated.