Boron-Doped Nanomaterials/Copper Synergistic Photocatalytic C(sp3)-N Cross-Coupling

Heterogeneous photocatalysis has emerged as a sustainable paradigm for C-N bond construction; however, its application has been predominantly confined to C(sp2)-N couplings, typically relying on the modulation of nickel catalytic cycles. The efficient construction of C(sp3)-N bonds remains a formidable challenge due to the high energy barriers of alkyl-metal oxidative addition and the inability of traditional semiconductors to orchestrate radical kinetics. Herein, we report a robust and versatile C(sp3)-N cross-coupling system enabled by a boron-doped nanomaterial (BDN) in synergy with a copper catalyst. The strategic incorporation of boron atoms─characterized by their vacant p-orbitals and Lewis acidity─into the heptazine framework transcends the role of simple light-harvesting, creating chemically active sites that effectively direct charge carrier separation and dictate alkyl radical generation. Extensive characterization, including quasi-in situ XPS and EPR, confirms that boron centers act as efficient electron acceptors, facilitating spatially directed charge transfer. This synergistic BDN/Cu platform accommodates an exceptionally broad substrate scope, including various N-nucleophiles (amides, sulfonamides, heterocycles) and diverse radical precursors (alkanes, alkyl boronic acids, and alkyl iodides). Furthermore, the protocol's synthetic utility is underscored by its successful extension to C(sp2)-N arylation and its seamless transition to a continuous-flow system, achieving gram-scale production. This work provides a general strategy for molecular-level engineering of heterogeneous catalysts to unlock challenging bond-forming transformations.