Cu (II) Complex Stabilized on Fe3O4@SiO2 Nanoparticles: An Effective and Recoverable Catalyst for the Preparation of Chromene Derivatives.

In the present research, we introduce a simple and efficient method for the synthesis of a new heterogeneous nanocatalyst including [Fe3O4@SiO2-L-Cu(II)] via immobilizing Cu (II) on the surfaces of Fe3O4@SiO2 nanoparticles (NPs). The prepared nanocatalyst was characterized by vibration sample magnetometer (VSM), EDS, X-ray diffraction (XRD), TGA, and Field emission scanning microscopy (FE-SEM) spectroscopic methods. The obtained magnetic nanocomposite showed excellent catalytic activity for the preparation of some chromene derivatives via a three-component reaction of aldehydes, 4‐hydroxycoumarin, and 2‐hydroxynaphthalene‐1,4‐dione. This synthetic procedure provides various benefits, including cost-saving, excellent yields in short reaction times (88–98%), low catalyst loading, and catalyst reusability. [ABSTRACT FROM AUTHOR]