A series of core–shell-structured poly(methylmethacrylate)@BaTiO 3 (PMMA@BT) composite particles were constructed via the self-assembly of BT nanoparticles on the surfaces of PMMA cores through the covalent bonding of siloxane groups at room temperature.
In the quest for efficient and recyclable heterogeneous catalysts for Sonogashira coupling reactions, a PEG-OMe (Methoxy Polyene Glycol) - mediated method was developed to immobilize Pd/Cu bimetallic nanoparticles on activated carbon (AC). Catalytic experiments showed that Pd/Cu@AC prepared in a PEG-OMe 500 had the highest activity. The morphology and composition of the catalyst were determined, and the identified crystallized and heterometallic nanoparticles of Pd/Cu were essential for an efficient catalytic cycle. The Pd/Cu@AC catalyst was successfully used in Sonogashira reactions (21 examples) including with aryl bromides as the coupling partner in EtOH at 80–100 °C. The catalyst was recycled at least nine times.
28 May 2019 in Journal of Materials Science: Materials in Electronics
In the palladium-catalyzed C−C coupling reaction, electron-rich phosphine ligands and a catalytic amount of catalyst loading are required in most cases. Herein, a bench-stable, easily modified and less toxic alkynone was utilized in palladium-catalyzed Sonogashira coupling to replace conventional phosphine ligands. With 1-(4-methoxyphenyl)-3-phenyl-2-yn-1-one (L2) as the ligand, catalyst loading was reduced to 5-10 ppm. In this newly developed catalytic system, a variety of (hetero)arene iodines and alkynes could be tolerated, resulting in good yields of the corresponding cross-coupling products.