Electrochemical Oxidation of Alcohols and Aldehydes to Carboxylic Acids Catalyzed by 4-Acetamido-TEMPO: An Alternative to Anelli and Pinnick Oxidations

An electrocatalytic method has been developed to oxidize primary alcohols and aldehydes to the corresponding carboxylic acids using 4-acetamido-2,2,6,6-tetramethyl-piperidin-1-oxyl (ACT) as a mediator. The method successfully converts benzylic, aliphatic, heterocyclic, and other heteroatom-containing substrates to the corresponding carboxylic acids in aqueous solution at room temperature. The mild conditions enable retention of stereochemistry adjacent to the site of oxidation, as demonstrated in a 40 g-scale synthesis of a precursor to levetiracetam, a medication used to treat epilepsy.