Efficient synthesis of polyhydroquinoline derivatives using a magnetic gelatin-chitosan hydrogel incorporating with ZnCo layered double hydroxide as a novel catalyst

Nanocatalysts play a crucial role in various fields, including chemical synthesis, energy production, energy conservation, and the reduction of environmental pollutants. A series of experiments was carried out at ambient temperature to assess the catalytic performance of a novel gelatin-chitosan hydrogel/ZnCo LDH/Fe₃O₄ nanocomposite in the asymmetric Hantzsch reaction. The individual components of the nanocomposite demonstrated a cooperative effect as a Lewis acid, facilitating the chemical reaction. The synthesis involved dimedone, ammonium acetate, ethyl acetoacetate, and various substituted aldehydes to produce a range of polyhydroquinoline derivatives. The nanocomposite displayed remarkable catalytic efficiency (exceeding 91 %) and stability (maintaining 83 % of its initial activity after four cycles) during the one-pot asymmetric synthesis. The findings highlighted numerous advantages, such as high product yields, short reaction times, operation at room temperature without special conditions, and easy recovery through an external magnetic field post-reaction. These results indicate the potential of this magnetic nanocatalyst for outstanding performance. Comprehensive characterization of the Ge-Cs hydrogel/ZnCo LDH/Fe₃O₄ nanocomposite was performed using techniques such as FT-IR, XRD, FE-SEM, EDX, VSM, and TGA. These analyses provided valuable insights into the composition and properties of the nanocomposite, contributing to a deeper understanding of its potential applications.