Synthesis and characterization of ethylene glycol substituted Mn(III) porphyrins. Catalysis with ethylene glycol substituted Mn(III) porphyrins at ambient temperature. Oxidation of cis-cyclooctene and cyclohexane in the presence of hydrogen peroxide. Catalysts’ performance depends on the number of ethylene glycol moieties present. Tetrasubstituted free-base porphyrin is studied by single-crystal X-ray diffraction.