Hyper-Cross-Linked Pyridine-Functionalized Bis(imino)acenaphthene-<i>N</i>-heterocyclic Carbene (BIAN-NHC) Palladium Catalysts for Superior Suzuki–Miyaura and Buchwald–Hartwig Coupling Reactions

Abstract

The design and synthesis of a series of palladium-loaded hyper-cross-linked polymer (HCP) catalysts, demonstrating high catalytic activity and excellent cycling stability in Suzuki–Miyaura and Buchwald–Hartwig coupling reactions is reported. By employing pyridine-functionalized BIAN-NHC as the building unit, HCPs with rich hierarchical pore structures and high surface areas were prepared. Notably, HCP-BIAN-Pd-2 exhibited superior catalytic activity and achieved a 99% yield with less reactive benzyl chloride, maintaining a 95% yield even after 10 cycles. This study addresses the issues of cost, toxicity, and recyclability associated with traditional homogeneous palladium catalysts, significantly enhancing the catalytic activity and stability by selectively introducing pyridine-functionalized BIAN-NHC ligands. These findings highlight the immense potential of these catalysts for large-scale production and practical applications, underscoring their significant practical implications in the field of heterogeneous catalysis.