Highly efficient cascade-oxygen-transfer from H2O2 to olefins mediated by halogenated carbonyl compounds and metalloporphyrins

The catalytic oxidation of cyclohexene with hydrogen peroxide promoted by manganese and iron porphyrins has been studied in the presence of halogenated carbonyl compounds as co-catalysts in a dichloromethane/water biphasic medium. The efficiency of the overall catalytic process is strictly related to the nature of the co-catalyst and to the high reactivity of its perhydrate form toward metalloporphyrins in forming an high valent oxo-pororphyrin derivative. Hydrogen peroxide fixation by hexafluoroacetone hydrate provides an useful system to hamper catalyst bleaching and/or oxidant decomposition. Thus, a complete olefin conversion into oxygenated products is accomplished with a very limited excess of oxidant respect to the organic substrate. (C) 2001 Elsevier Science B.V. All rights reserved.