Remarkable solvent effect on the yield and specificity of oxidation of naphthalene catalyzed by iron(III)porphyrins

Abstract

Oxidation of naphthalene was performed with tetrakis(pentaflourophenyl)porphyrin iron(III)chloride (F 20TPPFe IIICl), or tetrakis(2,6-dichlorophenyl)porphyrin iron(III)chloride (TDCPPFe IIICl), or tetramesitylporphyrin iron(III)chloride (TMPFe IIICl) as catalyst and metachloroperbenzoic acid or pentafluoroiodosylbenzene or tert-butylhydroperoxide as oxidant in different media in the presence of imidazole as cocatalyst. In aprotic solvent (CH 3CN:CH 2Cl 2, 1:1) and in the presence of F 20TPPFe IIICl, 1-naphthol, 2-naphthol and 1,4-naphthoquinone yields based on metachloroperbenzoic acid oxidant were 77.7, 2.1 and 5.6%, respectively. The best yield for 1,4-naphthoquinone in methanol with F 20TPPFe IIICl was 52.8%. The effect of bases on the yield and specificity of the naphthalene oxidation were studied. When imidazole changed to pyridine in F 20TPPFe IIICl, the yield of 1-naphthol decreased from 77.7 to 55.3%, whereas for TDCPPFe IIICl catalyst, the yield changed from 61.1 to 18.3%.