Effects of metal and porphyrin structure on the yield and chemoselectivity of naphthalene oxidation; a comparative study for manganese and iron

Oxidation of naphthalene was performed with various manganese and iron porphyrins as catalysts and metachloroperbenzoic acid, tert-butylhydroperoxide, and hydrogen peroxide as oxidants, in the presence of imidazole as cocatalyst. With m-CPBA, in low concentration of catalyst, iron porphyrin shows a higher catalytic activity than manganese porphyrin, while a greater amount of manganese porphyrin is needed for having a good catalyst. In the presence of excess amount of H2O2 oxidant in CH3OH solvent, manganese porphyrin acts better than iron porphyrin; however with the same oxidant and in aprotic solvent such as CH3CN:CH2Cl2 again iron shows a higher activity than manganese. Moreover, the effects of metalloporphyrin concentration on the selectivity, activity and stability of catalyst were studied in H2O2-catalytic oxidation. Copyright (c) 2005 Society of Porphyrins & Phthalocyanines.