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 m anganese and iron porphyrins has been studied in the presence of halogenate d carbonyl compounds as co-catalysts in a dichloromethane/water biphasic me dium. The efficiency of the overall catalytic process is strictly related t o the nature of the co-catalyst and to the high reactivity of its perhydrat e form toward metalloporphyrins in forming an high valent oxo-pororphyrin d erivative. 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 accomplish ed with a very limited excess of oxidant respect to the organic substrate. (C) 2001 Elsevier Science B.V. All rights reserved.