Hierarchical phosphorus-enriched organic polymer supports for immobilized palladium catalysts: enabling green and efficient Buchwald–Hartwig amination

Abstract

Heterogeneous palladium catalysts supported on phosphorus-rich cross-linked organic polymers provide a sustainable solution to the scarcity of Pd resources in the chemical industry. We synthesized COP-BINAP by utilizing (±)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) as monomers and then supported palladium on COP-BINAP to generate the heterogeneous Pd catalyst COP-BINAP-PdCl₂. This catalyst demonstrated excellent catalytic activity and substrate adaptability in Buchwald–Hartwig cross-coupling reactions. Even after five reuse cycles, COP-BINAP-PdCl₂ maintained high catalytic activity and structural stability, with consistent Pd loading amounts. This approach effectively addresses challenges related to recycling and reusing homogeneous precious metal catalysts, offering a promising strategy to alleviate precious metal scarcity and reduce environmental pollution risks.