For many years, the procurement of heterogeneous catalysts has been a main field of sub-nanotechnology and remains so nowadays [1–3]. The approach to preparation must be examined in activity and selectivity, that both depend on the atom arrangement at a scale smaller than 0.02 nm. sufficient access of reactants to the surface must be prepared. Catalysts mostly are used in the form of cylinders or pellets prepared by extraction, pressing, or other techniques . Currently, synthesis and application of functionalized magnetic particles have caused high fondness [5, 6]. Because of their wide range of applications, including magnetic resonance imaging , targeted drug delivery , environmental remediation [9, 10] and catalysis [11, 12]; magnetic nanoparticles are a great topic for research. The magnetic separation technique is a promising method for solid-liquid phase separation .
Magnetic materials are always synthesized based on a magnetic magnetite (Fe3O4) or maghemite (Fe2O3) core, which is afterward improved with other compounds to form various configurations [14, 15]. Due to their magnetic properties, a magnetic field is applied easily to separate the sorbent from the solution, which makes the separation process simple, fast and highly effective. As a result, magnetic materials have been used widely and successfully in pre-treatment of samples, specifically in biochemistry at an early period, such as drug delivery, cell image, and biomolecule detection [16–20].
Fe3O4 nanoparticles could easily be synthesized and covered in a high surface area. Meanwhile, scientists tried to functionalize Fe3O4 nano-particles with some compounds, such as chitosan , humic acid , and gum Arabic  to improve their selectivity, adsorption capacity, and stability. These functionalized magnetic nanoparticles were found to be cost-efficient, chemically stable, and environment friendly compared to the Fe3O4 nano-particles.
In this work, we prepared to functionalize Fe3O4 with glucose. Xanthenes; as a fascinating type of oxygen-containing compounds , have attracted a great notice for their vast range of medical and biological properties  such as antiviral , antibacterial  and anti-inflammatory operations ; and their wide applications in material science [30–32] and in photodynamic therapy . These various applications have led to the great interest of synthetic chemists in developing and improving their synthesis methods . In that way, the progress of nanocatalysts in various organic synthesis has received much attention [34, 35]. Especially, heterogenous nanocatalysts are suitable to synthesis of these heterocyclic compounds because of their ability to recovery and easy separation by an outer magnet, centrifugation techniques or several filtrations [36–39].
The unusual coupling of 4-(3,3-dimethyl-1-oxo-2,3,4,9-tetrahydro-1H-xanthen-9-yl)-5-hydroxycyclohex-4-ene-1,3-dione in the presence of transition metal cations has been reported solely by our research group . Herein, we could improve the coupling reaction by a novel heterogeneous nanocatalyst (Fe3O4@C/[email protected]2) as a highly efficient nanocatalyst.