Nickel-embedded three-in-one pyridyl-quinoline-linked covalent organic framework photocatalysts for universal C(sp2) cross-coupling reactions

)-carbon and heteroatom (S, N, O, B, P, Se, and Cl) bond formations across a broad range of aromatic halides and nucleophiles, while maintaining low metal loading (1-2 mol%). The Ni-PQCOFs, featuring fully conjugated and tunable pyridyl-quinoline (PQ) motifs, exhibit exceptional (photo)chemical stability, broadened absorption wavelength range, and enhanced redox capability. Remarkably, these COF-based heterogeneous metallaphotocatalysts exhibited significantly enhanced catalytic efficiency compared to their homogeneous counterparts. The versatility and practicality of this photocatalytic system extend to diverse synthetic applications, including late-stage functionalization of complex molecules, sequential functionalizations, and decagram-scale synthesis assisted by an in-house-built high-speed circulation flow system. Moreover, the micrometer-sized Ni-PQCOF catalyst could be recycled over 10 times through direct filtration with minimal activity loss and negligible metal leaching. All these advantages establish Ni-PQCOFs as versatile, effective, and sustainable metallaphotocatalysts for cross-coupling reactions.