Direct Knitting of Pincer Palladium Complexes into Hyper-crosslinked Polymers for Superior Catalytic Performance in Suzuki-Miyaura Reactions.

Using a direct knitting strategy, we successfully prepared a novel heterogeneous catalyst consisting of pyridine-bridged bis(imidazolium-2-ylidene) palladium complexes (CNC-Pd) embedded in a knitted network polymer. The resulting catalysts (HCP-CNC-Pd-d) exhibited high specific surface areas of 982 m2 g-1 with microporous and mesoporous structures. The large surface area enhances contact between the substrate and the catalytic center, while the strong chelation between CNC and the metal ion ensures the catalyst's durability. The HCP-CNC-Pd-d catalysts exhibited superior performance, achieving an impressive 99% yield in the Suzuki coupling reaction between bromobenzene and phenylboronic acid. The catalyst also demonstrated good performance across a range of substrates in the Suzuki-Miyaura coupling reactions. Furthermore, the catalyst could be recycled for over 10 cycles without any significant loss in activity and selectivity. This highly cost-effective and convenient approach provides valuable insights into the design and application of heterogeneous catalysts in various fields.