Nano-peanut shell-OSO3H: Green and natural-based renewable nanocatalyst for one-pot synthesis of dihydropyrano[3,2-b]chromenedione derivatives

Nano-peanut shell‑OSO3H nanoparticles were simply prepared and characterized by the scanning electron microscopy (SEM), transmission electron microscope (TEM), fourier transform infrared (FT-IR), energy dispersive X-ray spectroscopy (EDX), and thermal analysis techniques (TGA/DTG). The catalytic activity of nano-peanut shell‑OSO3H was studied in the synthesis of biologically important 4H-pyran derivatives. The reaction involves the use of Kojic acid, 5,5-dimethyl-1,3-cyclohexanedione, and various benzaldehydes. A wide range of benzaldehydes is compatible in this reaction, producing excellent yields in a short time. The successful synthesis of dihydropyrano[3,2-b]chromenedione derivatives shows that nano-peanut shell‑OSO3H has high catalytic activity and can be effectively used as a green catalyst.