Strategy for controlling the Kolbe electrosynthesis in the presence of aromatic fragments and amino groups in the molecule

A general characteristic of processes that occur during anodic oxidation of phenylacetic and phenylpropionic acids and derivatives of alpha- and beta -amino acids on platinum electrodes in methanol and mixed pyridine-methanol solutions is given. From preparative electrolyses in stagnant and flow-thr ough reactors, conditions are determined under which the dimerization (Kolb e electrosynthesis) is least complicated by the formation of polymer produc ts. Properties of removed electrodes, on which stable polymer films formed during the electrosynthesis, are examined. For films formed in certain cond itions on the cathode, the presence of a quasireversible redox transition i s demonstrated. Such films contain disperse platinum codeposited with polym er as a result of the anode dissolution in the cells with common compartmen ts. In principle, the film-modified electrodes can be used for controlling anodic decarboxylation.