Fe(3)O(4)@nano-almondshell/Si(CH(2))(3)/2-(1-piperazinyl)ethylamine as an effective magnetite almond shell-based nanocatalyst for the synthesis of dihydropyrano[3,2-c]chromene and tetrahydrobenzo[b]pyran derivatives

The preparation and design of nano-catalysts based on magnetic biopolymers as green and biocompatible nano-catalysts have made many advances. This paper deals with the preparation of magnetite biopolymer-based Brønsted base nano-catalyst from a nano-almond (Prunus dulcis) shell. This magnetite biopolymer-based nano-catalyst was obtained through a simple process based on the core-shelling of nano-almond shell and Fe(3)O(4) NPs and then the immobilization of 3-chloropropyltrimethoxysilane as linker and 2-aminoethylpiperazine as a basic section. Structural and morphological analysis of this magnetite biopolymer-based nano-catalyst were done using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, Thermogravimetric analysis, Vibrating sample magnetization, Energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, and Transmission electron microscopy techniques. The performance of the synthesized Fe(3)O(4)@nano-almondshell/Si(CH(2))(3)/2-(1-piperazinyl)ethylamine as a novel magnetite biopolymer-based nano-catalyst for the synthesis of dihydropyrano[3,2-c]chromene and tetrahydrobenzo[b]pyran was investigated and showed excellent efficiency.