Direct C1 homologation of carboxylic acids: free radical approach enabled by acridine catalysis

Abstract

A photocatalytic C1 homologation of carboxylic acids is described. The transformation is performed in a convenient one-pot procedure. The key step is decarboxylative radical addition to a tosylhydrazone derived from ethyl glyoxylate, which is mediated by a dual acridine/decatungstate photocatalytic system. The resulting hydrazide intermediate is easily converted to the homologated carboxylic ester by treatment with a base.