Iron perchlorophthalocyanine and tetrasulfophthalocyanine catalyzed oxidation of cyclohexane using hydrogen peroxide, chloroperoxybenzoic acid and tert-butylhydroperoxide as oxidants

Polychlorophthalocyanine ((ClPcFeII)-Pc-16,) and tetrasulfophthalocyanine ([Fe(II)TSpC](4-)) complexes of iron are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), m-chloroperoxybenzoic acid (m-CPBA) and hydrogen peroxide as oxidants. Catalysis using the (ClPcFeII)-Pc-16 was performed in a dimethylformamide:dichloromethane (3:7) solvent mixture. For the [(FeTSPc)-T-II](4-) catalyst, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative yields of the products depended on oxidant and the catalyst. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. The mechanism of the oxidation of cyclohexane in the presence of the (ClPcFeII)-Pc-16 and [FenTSpC](4-) involves the oxidation of these catalysts, forming an Fe(III) phthalocyanine species as an intermediate. Higher yields were observed when [FeTSpC](4-) was employed as a catalyst, which is more soluble than the perchlorinated iron phthalocyanine catalyst. (C) 2002 Elsevier Science B.V. All rights reserved.