Esterification, Etherification, and Aldol Condensation Using Cathodically-Generated Organic Olate Anions

Abstract

Cathodic methods for the esterification of carboxylic acids and the etherification of phenol and benzenethiol under mild conditions were developed. The esterification was successfully carried out at room temperature by the reaction of alkylating reagents with cathodically-generated quaternary ammonium carboxylates. The etherification was similarly achieved using electrogenerated quaternary ammonium phenolate and halonitrobenzenes. A hindered phenolate anion cathodically-generated from 2,6-di-t-butyl-p-cresol remarkably promoted aldol condensation of aromatic ketones and aldehydes, and allowed subsequent Michael reaction to provide efficiently symmetrical 1,5-diketones.