ANODIC OXIDATIONS .5. KOLBE OXIDATION OF PHENYLACETIC ACID AND 1-METHYLCYCLOHEXANEACETIC ACID AT PLATINUM AND AT CARBON

The Kolbe oxidations of phenylacetic acid and 1-methylcyclohexaneacetic acid have been studied at both platinum and carbon anodes. At platinum, the products are derived from both free-radical and cationic intermediates, with products resulting from free radicals predominating. At a carbon anode, almost all of the products result from the generation of carbonium ions at the electrode. Itis suggested that this unique ability ofa carbon anode to promote the generation of carbonium ions is due to the presence within carbon of paramagnetic centers which bind the initially formed radicals, impede their desorption, and, therefore, promote a second electron transfer. © 1969, American Chemical Society. All rights reserved.