Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO.

An efficient one-step synthesis of diarylacetic acids was successfully performed by electrochemical direct carboxylation of diarylmethanol compounds in DMSO. Constant-current electrolysis of diarylmethanol species in DMSO using a one-compartment cell equipped with a Pt cathode and a Mg anode in the presence of carbon dioxide induced reductive C(sp³)-O bond cleavage at the benzylic position in diarylmethanol compounds and subsequent fixation of carbon dioxide to produce diarylacetic acids in good yield. This protocol provides a novel and simple approach to diarylacetic acids from diarylmethanol species and carbon dioxide without transformation of the hydroxy group into appropriate leaving groups, such as halides and esters including carbonates.