Palladium nanoparticles from β-cyclodextrin and cellulose methyl carboxylate as an effective catalyst for Sonogashira coupling and the reduction of alkynes

This research presents an effective approach for synthesizing palladium nanoparticle (PdNP) catalysts, employing β-cyclodextrin (β-CD) as a reducing agent and cellulose methyl carboxylate (CMC) as a stabilizer. PdNP-based nanocomposites were prepared by varying the mass ratios of CMC to β-CD from 1 : 1 to 3 : 2. Their structural and physicochemical properties were thoroughly analyzed using multiple characterization techniques, including ultraviolet-visible spectroscopy (UV-vis), FTIR, DLS, Zeta potential, XRD, TGA, and TEM. The resulting PdNPs exhibited a crystalline structure with particle dimensions spanning from 2 to 10 nm, with the majority falling between 4 and 6 nm. These nanoparticles demonstrated outstanding catalytic activity in Sonogashira coupling reactions, operating without additional catalysts and efficiently converting alkynes into (<i>Z</i>)-alkenes utilizing KOH/DMF as a hydrogen donor. The high yield and selectivity observed highlight the potential of CMC/β-CD-stabilized PdNPs as promising catalysts for organic synthesis applications.