This work describes the preliminary study of the homogeneous oxidation reaction of cyclohexene by nitro complexes of copper(II), Cu(CH3CN)(2)(NO2)Cl (1) and Cu(CH3CN)(2)(NO2)(2) (2) in acetonitrile, under oxygen pressure (20 atm) at 70 and 100 degrees C. The results show the formation of 2-cyclohexen-1-one and 1,2-epoxyhexane-3-one as main reaction products. Also, it was observed that the oxidation reaction at 100 degrees C with complexes 1 and 2 becomes more selective to the formation of 2-cyclohexene-1-one although the activity of both catalyst decreases.