We have systematically investigated heterogeneous catalytic oxidation of different substrates in supercritical carbon dioxide (SC-CO 2 ). Three types of catalysts, a metal complex {cis-[Fe-(dmp) 2 (H 2 O) 2 ] (CF 3 SO 3 ) 2 } (dmp ) 2,9-dimethyl-1,10-phenanthroline), 0.5% platinum γ-alumina, and 0.5% palladium γ-alumina, were used at a pressure of 200 bar, at temperatures from 60 to 150°C, and for 3-18 h for partial oxidation of organic substrates. The metal-oxo catalyst used gave as high as 3.9% conversion of cycloxene to its oxides and epoxides, with the major products being the ketone and alcohol. The oxidation of cyclohexene strongly depended on the concentration of oxygen, whereas length of reaction (3-18 h) and temperature (60-150°C) were shown to be less significant on the conversion and selectivity of the reaction. Oxidation of cyclohexene over Pd and Pt/Al 2 O 3 catalysts resulted in a mixture of dehydrogenation and oxygenated products.