Pd Nanoparticles Immobilized on Biomimetically Synthesized Carboxymethylcellulose/Calcium Carbonate Hybrids for Ligand-Free Suzuki-Miyaura Reactions

The efficient biomimetically fabricated Pd nanoparticles immobilized on carboxymethylcellulose/calcium carbonate (Pd(0)NPs@CMC/CaCO3) hybrid have been developed for ligand-free SuzukiMiyaura cross-couplings. The Pd(0)NPs@CMC/CaCO3 hybrid was well characterized and evaluated over a wide range of substrates with both functional group and halide substituents. The results demonstrated that the Pd(0)NPs@CMC/CaCO3 possesses remarkable catalytic activity, good substrate tolerance, and high stability. These unique characteristics may be attributed to the chelation of Pd-0 species with the carboxylate and hydroxy groups of CMC entrapped in the Na-CMC/CaCO3 hybrids. Moreover, the catalyst could be reused at least six times with virtually no evident loss of its catalytic activity and degradation of its structure, thereby offering a sustainable and practical synthetic methodology.