Silver and copper-magnetite nanocomposites as green and magnetic recoverable catalysts for the preparation of cyclopentadiene derivatives from a tri-component condensation

Utilizing Citrus sinensis peels extract, acting as the stabilizing and reducing agents, an eco-friendly and green method is described for the preparation of copper/magnetite and silver/magnetite nanocomposites (NCs) via biological reduction of Ag+ and Cu2+ ions. The total phenolic compounds of the C. sinensis peels extract and extract's ability to inhibition the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical were determined. The obtained results verified which the C. sinensis peels extract has the capability to reduce the silver(I) and copper(II) ions to its metallic nanoparticles (NPs). The deposition of silver and copper NPs on magnetite (Fe3O4) ones was confirmed by absorption bands at lambda(max) values of 422 and 732 nm in their UV-Vis spectra, being related to the plasmon bands of silver and copper NPs. The catalytic performance of silver/Fe3O4 and copper/Fe3O4 NCs was investigated in the three-component condensation reaction of synthesis of 1,3-cyclopentadiene derivatives. The present synthetic method is the simple, economic, green route and effective with high efficiency.