Biomimetic oxidation of ibuprofen with hydrogen peroxide catalysed by horseradish peroxidase (HRP) and 5,10,15,20-tetrakis-(2 ',6 '-dichloro-3 '-sulphonatophenyl) and manganese(III) hydrates in AOT reverse micelles

The oxidation of ibuprofen with H2O2 catalysed by Horseradish peroxidase (H RP), Cl8TPPS4Fe(III)(OH2)(2) and Cl8TPPS4Mn(III)(OH2)(2) in AOT reverse mic elles gives 2-(4'-isobutyl-phenyl)ethanol (5) and p-isobutyl acetophenone ( 6) in moderate yields. The reaction of ibuprofen (2) with H2O2 catalysed by HRP form carbon radicals by the oxidative decarboxylation, which on reacti on with molecular oxygen to form hydroperoxy intermediate, responsible for the formation of the products 5 and 6. The yields of different oxidation pr oducts depend on the pH, the water to surfactant ratio (Wo), concentration of Cl8TPPS4Fe(III)(OH2)(2) and Cl8TPPS4Mn(III)(OH2)(2) and amount of molecu lar oxygen present in AOT reverse micelles. The formation of 2-(4'-isobutyl phenyl)ethanol (5) may be explained by the hydrogen abstraction from ibupr ofen by high valent oxo-manganese(IV) radical cation, followed by decarboxy lation and subsequent recombination of either free hydroxy radical or hydro xy iron(III)/manganese(III) porphyrins, The over-oxidation of 5 with high v alent oxo-manganese, Mn(IV)radical cation intermediate form 6 in AOT revers e micelles by abstraction and recombination mechanism. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.