Development of a recyclable GO-metformin-Pd(0) nanocatalyst for ecofriendly synthesis of quinoline-4(1H)-ones and flavones via multicomponent-carbonylation reactions

In this method, a sustainable and reusable nanocatalyst, GO/MNPs-Met-Pd(0), was developed by anchoring Pd(0) complexes onto metformin-functionalized graphene oxide-magnetic nanoparticles. Comprehensive characterization using FT-IR, XRD, VSM, SEM, TEM, TGA, BET, EDX, elemental mapping, and ICP-OES confirmed the catalyst’s structure and composition. The catalytic performance of GO/MNPs-Met-Pd(0) was evaluated in two multicomponent reactions for the efficient synthesis of quinoline-4(1H)-one and flavone derivatives. Conducted in ionic liquid media, the reactions yielded quinoline-4(1H)-ones (15 examples) with 88–99 % yields and flavones (12 examples) with 85–98 % yields. The catalyst demonstrated excellent reusability with minimal activity loss over multiple cycles. These results highlight GO/MNPs-Met-Pd(0) as a highly efficient, selective, and eco-friendly catalyst for the sustainable synthesis of valuable heterocyclic scaffolds. Compared to previously reported methods for preparing quinoline derivatives via carbonylation reactions, this method has prominent features such as the following: use of a green catalyst with high efficiency, recyclability, and stability, carrying out carbonylation reactions in an ionic liquid as a green solvent, and synthesis of products with very high yields in 1 h.