Copper immobilized on magnetite nanoparticles coated with ascorbic acid: An efficient and reusable catalyst for C─N and C─O cross‐coupling reactions

In a continuation of using magnetic nanoparticle (MNP)‐supported catalysts, ascorbic acid (readily available, very safe and with strong affinity to MNPs) was used instead of the commonly used silica layer coating. This hybrid was used for immobilizing copper nanoparticles to produce Cu/ascorbic acid@MNPs catalyst. The catalyst was characterized and used in carbon–oxygen and carbon–nitrogen (various substrates) cross‐coupling reactions in aqueous media and at room temperature with excellent product yields. Furthermore, the catalyst could be quickly and completely recovered using an external magnetic field and reused for six reaction cycles without significant change in catalytic activity. Coating of magnetic Fe3O4 nanoparticles with ascorbic acid, as safe and available compound, was reported for the first time which used for immobilization of copper particles and prevention the MNPs aggregation. This new and efficient magnetic copper (I) nanocatalyst was employed in C‐N and C‐O coupling reactions in water and room temperature conditions.