Environmentally benign oxidation of alcohols using transition metal catalysts

Recently reported oxidation process of alcohols using molecular oxygen as an oxidizing agent in the presence of catalytic amount of transition metals such as copper, ruthenium, palladium compounds will be reviewed. Oxidation of alcohols based on hydrogen transfer reaction between alcohols and simple olefins such as ethylene is also described. That is, some benzylic and allylic alcohols can be converted into the corresponding carbonyl compounds using a catalytic amount of palladium on activated carbon (Pd-C) under ethylene atmosphere. The combination of Pd(OAc)(2) and vinyl acetate also works efficiently. Selective oxidation of hydroxy groups on carbohydrates (D-glycals) and steroids as well as simpler systems has been achieved. These environmentally benign oxidation methods have potentialities to replace the conventional stoichiometric chromium and other metal oxides reagents.