Hydrocarbons metalloporphyrin-catalyzed

Iodosylbenzene has been used as an effective oxidant in hydrocarbon hydroxylation catalyzed by metal-loporphyrins [687-696]. In particular, various iron(III) and manganese(in) porphyrins can be used as catalysts in hydroxylations of cyclohexane, cyclohexene, adamantane and aromatic hydrocarbons [687,688, 692]. Breslow and coworkers have reported regioselective hydroxylations of several steroidal derivatives catalyzed by metalloporphyrins [689-691]. In a specific example androstanediol derivative 644 was... 

IBX esters can serve as stable and efficient sources of oxygen in the metalloporphyrin-catalyzed oxidations of hydrocarbons and the reactivity of isopropyl 2-iodoxybenzoate as an oxygenating reagent is similar to that of commonly used iodosylbenzene, which is a thermally unstable and potentially explosive compound [713, 1129, 1130]. 

Guo, C.C., J.X. Song, X.B. Chen, and G.R Jiang (2000). A new evidence of the high-valent oxo-metal radical cation intermediate and hydrogen radical abstract mechanism in hydrocarbon hydroxylation catalyzed by metalloporphyrins. J. Mol. Cat. A 157, 31-40. 

In a number of model studies it has been demonstrated that synthetic porphyrin complexes are able to be oxidized to oxo-metalloporphyrin complexes which will, in turn, oxidize organic substrates of the type mentioned previously. Thus, in an early investigation it was shown that a synthetic Fe(m) porphyrin will catalyze oxygenation of hydrocarbons using iodosylbenzene as the reduced-oxygen source (Groves, Nemo Myers, 1979). Following this report, a number of related cytochrome... 

Oxidation Catalyzed by Metalloporphyrins. Much attention has been devoted to the metal-catalyzed oxidation of unactivated C—H bonds in the homogeneous phase. The aim of these studies is to elucidate the molecular mechanism of enzyme-catalyzed oxygen atom transfer reactions. Additionally, such studies may eventually allow the development of simple catalytic systems useful in functionalization of organic compounds, especially in the oxidation of hydrocarbons. These methods should display high efficiency and specificity under mild conditions characteristic of enzymatic oxidations. 

Two kinds of systems based on Fe(III) or Mn(III) porphyrins are available now for the oxidation of hydrocarbons. The first ones involve such a metalloporphyrin catalyst and an oxygen atom donor like PhIO, H2O2 or O2 and a reducing agent 2-10 They reproduce quite well the reactions catalyzed by cytochrome P450-dependent monooxygenases and involve a high-valent metal-oxo active species which is able to epoxidize alkenes, hydroxylate alkanes and aromatic compounds and perform N- or S- oxidations. 

In some cases metalloporphyrins have been found to catalyze the autoxidation of alkanes or the alkyl groups of other saturated hydrocarbons (alkylaromatics, cycloalkanes, etc.) [85]. Typically,... 

Mlodnicka, T. Metallopoiphyrin-Catalyzed Oxidation of Hydrocarbon with Dioxygen, In Metalloporphyrins in Catalytic Oxidation, Sheldon, R. A., Ed Marcel Dekker, Inc. New York, Basel, Hong Kong, 1994 p. 261. 

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