Layered Ni(II) complex on magnetic nanoparticle as heterogeneous, efficient, novel, green, and reusable catalyst was used to cross‐coupling reaction, including carbon–carbon, carbon–nitrogen, and carbon–oxygen formations. The covalent functionalization of organic ligand, thiocarbohydrazide (TCH), on the surface of magnetic nanoparticle (Fe3O4) was determined that leading to an exceptional adsorptive ability for supporting Ni(II). The magnetic nano‐composite was characterized and investigated by using Fourier‐transform infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), energy dispersive X‐ray (EDX), X‐ray diffraction (XRD), scanning electron microscope (SEM), inductively coupled plasma–optical emission spectrometry (ICP‐OES), transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). Also, three cross‐coupling reactions in the presence of Fe3O4@TCH@Ni(II) were optimized in terms of temperature, amount of catalyst, solvent, and time.

A magnetic nanostructured iron/silica/ linker/ gold ions/ chitosan, has been synthesized to achieve an efficient and reusable catalyst characterized by X-ray diffraction, scanning, and transmission electron microscopies, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and inductively coupled plasma optical emission spectrometry. To improve their stability and increase surface the achieved multilayer nanocomposite has been capsulated in chitosan and glutaraldehyde network. It was found that the obtained nanoparticles have diameter size from 43 to 72 nm. The optimized nanocatalyst applied an efficient and easy friendly procedure for the synthesis of 3, 4-dihydropyrano [3,2-c]chromenes from aromatic aldehyde or aromatic glyoxal, malononitrile, and cyclohaxane-1,3-dione in water at room temperature. The prepared nanocatalyst will be quickly recovered employing an external magnet and reused several times without significant activity loss.

A magnetic nanostructured iron/silica/ linker/ gold ions/ chitosan, has been synthesised to achieve an efficient and reusable catalyst characterised by X-ray diffraction, scanning, and transmission electron microscopies, energy-dispersive X-ray spectroscopy,...