Innovative approach to synthesizing polyhydroquinoline and dihydropyrimidine derivatives from alcohols by g-C3N4/PANI/Cu2+ nanocomposite

This study introduces an innovative and sustainable approach for synthesizing polyhydroquinoline and dihydropyrimidine derivatives directly from alcohols via in situ oxidation to aldehydes, using a nanocomposite catalyst composed of graphitic carbon nitride (g-C₃N₄), polyaniline (PANI), and copper ions (Cu²⁺). The g-C₃N₄/PANI/Cu²⁺ catalyst exhibited excellent catalytic performance, affording yields of 63-84% under relatively mild and environmentally acceptable conditions. Comprehensive characterization by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM) supported the successful formation and structural stability of the nanocomposite. Mechanistic insights suggest that cooperative interactions among g-C₃N₄, PANI, and Cu²⁺ species facilitate the in situ oxidation of alcohols and subsequent multicomponent condensation, leading to heterocyclic frameworks. Overall, this methodology provides an efficient and sustainable catalytic pathway for synthesizing biologically relevant heterocycles with potential applications in pharmaceuticals and materials science.