Phase-Transfer-Catalyzed Oxidation and Reduction of Organosulfur Compounds with Dichlorocarbene. Mechanism and Synthetic Utility

Article abstract of DOI:10.1021/jo01314a029

Diaryl and dialkyl sulfoxides undergo facile phase-transfer-catalyzed (PTC) deoxygenation with dichlorocarbene at 25 deg C to afford excellent yields of sulfides.Comparisons of deoxygenation rates of dialkyl and diaryl sulfoxides suggest that steric acceleration occurs with the bulky sulfoxides while resonance interactions from aromatic rings retard the reduction.Less bulky sulfides also undergo the reverse reaction: addition of dichlorocarbene to the sulfide with hydrolysis of the dialkyl dichloromethylide with hydroxide ion to afford the corresponding sulfoxide. "Oxidation" of trans-thiadecalin by reaction with PTC dichlorocarbene addition followed by basic hydrolysis is highly stereoselective, affording 94 percent axial and 6 percent equatorial sulfoxide.