Catalytic Deoximation of Oximes by PIDA in the Presence of Mn(TPP)OAc

Manganese can frequently be found in the catalytic redox center of several enzymes including superoxide dismutase, catalase, and the oxygen-evolving complex photosystem II. Ti gain insight into the mechanism of these enzymes, a variety of Mn complex such as manganese porphrins; the active mimic of cytochrome  P-450, have been developed. Mn prophyrins and several other metal porphyrins, in particular Fe and cr system, have been studied intensively as catalysts in epoxidation of alkenes, hydroxylation of alkanes, hydroxylation of alkanes, decarboxylation of carboxy acids, aromatization of 1,4- dihydropyridines, and oxidation of sulfides. In these catalytic conversions, a variety of oxidants such as iodosylarenes .alkylhydroperoxides, hydrogen peroxide, priodates ,hypochloride, etc .were employed. Herein, we report an efficient method for deoximation of oximes by phenyliodine (III) diacetate (PhI(OAc)2; PIDA) in the presence of manganese (III) meso-tetraphenylporphyrin acetate (Mn(TPP)OAc) and imidazole at room temperature. A high-Valent manganese-oxo porphyrin complex (Mn=O) was considered as a reactive oxidation intermediate according to an investigation by Uv-Visible spectroscopy. While the steric properties of the substrate (alkenes and oximes) Used in this study are of paramount importance in determining the overall catalytic reaction times and oxidation yields (%),