Oxygenation of Dimethylsulfoxide and Copper‐Catalyzed Autoxidation of Substituted Benzoins

The catalytic activity of autoxidized copper (I) in the oxidation of para‐disubstituted benzoins in dimethylsulfoxide by O2 was studied both kinetically and by product analysis. Stoichiometry (1), accounts for more than 80% of the reaction. The catlytic oxydation was followed by monitering th consumption of O2 manometrically by a fully automatic apparatus. equation image (X = H, CH3, OCH3, C6H5 CI) A redox shuttle mechanism is proposed, where the rate‐determining step is the autoxidation of Cu(I) followed by a rapid oxidation of the substrate by an oxocupric species. The redox stiochiometry (I) corresponds to that found for external monooxy‐genases (or mixed‐function oxidases), and the significance of our results with respect to analogous catalytic systems is discussed.