A heterogeneous magnetic supported copper(II) nanocatalyst has been obtained through the reaction of 2-hydroxy-1-naphthaldehyde with the functionalized silica coated iron oxide nanoparticle (Fe3O4@SiO2@NH2) to synthesize immobilized Schiff base ligand (Fe3O4@SiO2/Schiff base). This procedure was followed by the addition of Cu(CH3COO)2·H2O to the prepared particles in order to form the copper(II) Schiff base complex on the surface of iron oxide nanoparticles. Versatile techniques such as FT-IR, SEM, XRD, ICP-OES, EDS and VSM were employed to characterize the synthesized Cu nanocatalyst. Furthermore, its catalytic functionality has been investigated for the oxidation of various olefins with the help of hydrogen peroxide (H2O2) as an eco-friendly oxidant. In the next step, the final samples of reactions were isolated quite simply by using magnets and analyzed by GC and GC–MS instruments. The obtained copper(II) nanocatalyst grants some superiorities such as simple magnetic separation from the mixture, short reaction time (2 h) and high conversion through green processes exclusively for styrene (conversion: 100%) and norbornene (conversion: 79%).