Photochemical Anion-Promoted Carbon-Sulfur Cleavage Reactions of Diaryl Sulfides, Alkyl Aryl Sulfides, and Related Sulfoxides and Sulfones

Article abstract of DOI:10.1021/jo00007a034

Diaryl sulfides and the related sulfoxides and sulfones react with substances such as diethyl phosphite anion, pinacolone enolate, and diphenylphosphide anion under irradiation to cleave one carbon-sulfur bond and form diethyl arylphosphonates, arylmethyl tert-butyl ketones, and aryldiphenylphosphines.Alkyl aryl sulfides and the related sulfones also experience carbon-sulfur bond cleavage under these conditions to produce arenethiols.Generally, these reactions occur in synthetically useful yields.The reactions of the anions with these sulfides, sulfoxides, and sulfones all require irradiation, but is notable that the reactions of diphenylphosphide anion occur in the visible region of the spectrum.Several lines of evidence suggest that the reaction proceeds via the familiar S_RN1 pathway and that the photochemically-induced electron transfer occurs in an arene-anion complex.Thermochemical considerations dictate the cleavage direction in the anion radicals of unsymmetrical sulfides.