Pd Nanoparticles Immobilized on Nanosilica Triazine Dendritic Polymer: A Reusable Catalyst for the Synthesis of Mono‐, Di‐, and Trialkynylaromatics by Sonogashira Cross‐Coupling in Water

Abstract Palladium nanoparticles immobilized on nano‐silica triazine dendritic polymer (Pd np ‐nSTDP) was found to be a highly effective catalyst for the Sonogashira cross‐coupling of aryl halides (iodides, bromides, and chlorides) with aromatic and aliphatic terminal alkynes. This reaction was best performed in water as a green solvent in the presence of just 0.01 mol‐% of the catalyst at room temperature. Efficient synthesis of V‐ and star‐shaped polyalkynylated molecules with a benzene, pyridine, or pyrimidine central core was also achieved through Sonogashira cross‐coupling of dihalo and trihalo aromatics with terminal alkynes in the presence of this catalytic system. The Pd np ‐nSTDP catalyst was easily recovered and reused several times without significant loss of reactivity.