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 beta-cyclodextrin (beta-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 beta-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 (Z)-alkenes utilizing KOH/DMF as a hydrogen donor. The high yield and selectivity observed highlight the potential of CMC/beta-CD-stabilized PdNPs as promising catalysts for organic synthesis applications.