In this study, the Zn (II)-Schiff base covalently anchored onto the surface of CaO@SiO2 nanoparticles. The structure of this hybrid nanomaterial (CaO@SiO2-NH2-Sal-Zn) was characterized using the analytical techniques such as Fourier transform infrared spectroscopy, field emission-scanning electron microscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma atomic mass spectrometry. The catalytic activity of this organic–inorganic hybrid nanostructure was investigated through the green synthesis of 4H-pyran derivatives via one-pot threecomponent condensation reaction which high yields of desired products obtained under green media. The reusability experiments confirmed the stability and high performance of this hybrid nanomaterial under the reaction conditions. The retrievability of this catalyst was proved by recycling six times in reactions without significant loss in its activity. Green conditions, use of available materials, easy work-up procedure, and high yield of products, low reaction times, and simple purification are some advantages of this protocol over earlier ones.
