Epoxidation using non-heme iron complexes in solution and immobilized on silica gel as catalysts

The epoxidation of the carbon-carbon double bound by metallocomplexes is systematically investigated using metallomacrocycles like metalloporphyrins as heme models for cytochrome P-450. Herein, we report the synthesis and characterization of a new complex [Fe2(bbppnol)(μ-AcO)(H2O)2](ClO4)2 (A), a non-heme metallocomplex, as well as its catalytic activity in olefin oxidation. The bis(aquo) complex A and [Fe2(bbppnol)(μ-AcO)2](PF6) (B) (previously prepared) were also immobilized on silica gel, and the obtained heterogeneous catalysts were characterized. The catalytic activity of such solid materials in the oxidation of cyclooctene and cyclohexene was investigated using iodosylbenzene and H2O2 as oxidants. The obtained results were compared with the catalytic behavior of the corresponding iron complexes in solution (homogeneous catalysis).