New and Effective Aerobic Oxygenation of Olefins Catalyzed by Transition-Metal Complexes

New and effective aerobic oxygenation reactions of olefins catalyzed by transition-metal complexes are described. (I) By the combined use of an atmospheric pressure of molecular oxygen and secondary alcohols, various kinds of olefins are converted into the corresponding alcohols in good to high yields catalyzed by a cobalt (II) complex. (2) Effective epoxidation of a wide variety of olefins involving styrenes and α,β-unsaturated carboxamide are achieved by the combination use of aldehyde and molecular oxygen catalyzed by nickel (II). iron(III). or oxovanadium(IV) complexes under mild reaction conditions. (3) Enantioselective aerobic epoxidations of unfuctionalized olefins are demonstrated by using optically active manganese (III) complexes as catalysts. (4) In the presence of acetal of aldehyde, cobalt(II) complex catalyzed aerobic epoxidation of olefins proceeds in high yield under neutral and mild conditions.