Asparagine-modified magnetic graphene oxide as efficient green nanocatalyst for synthesis of chromenes and pyrano pyrazoles derivatives

The primary focus of this study involved the fabrication of a novel nanocatalyst Fe₃O₄-supported asparagine functionalized graphene oxide Fe₃O₄@GO-N-(Asparagine). The catalyst was synthesized through a four-step procedure. The chemical composition of Fe₃O₄@GO-N-(Asparagine) was examined using various analytical methods, including scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and a Raman. The Fe₃O₄@GO-N-(Asparagine) catalyst demonstrated remarkable catalytic action in the synthesis of 5-oxo-dihydropyrano[3,2-c]chromenes as well as dihydropyrano[2,3-c]pyrazole derivatives. The protocol offered several benefits, including short reaction times, the utilization of green solvents, outstanding product yields, and a straightforward work-up procedure. Eventually, density functional theory (DFT) computations were utilized to calculate several parameters, including energy levels, electrostatic potential, and chemical reactivity descriptors based on highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies. Based on the calculations obtained from DFT, it was determined that the type and position of functional groups on the synthesized compounds had the most significant impact on the calculations.