Precise Tailoring of the Coordination Environment of Single‐Atom Cu(I) on Trifurcate AlL ₃ Supports for Click Chemistry

ABSTRACT Single‐atom catalysis hinges on fundamental challenges in precisely controlling metal‐support interactions and rationally regulating metal–adsorbate relationships. Herein, we report a universal strategy for constructing highly efficient and well‐defined Cu(I) single‐atom catalysts based on a trifurcate AlL 3 molecular support. This approach effectively stabilizes monovalent copper centers against disproportionation and aggregation—issues commonly encountered in conventional synthesis methods dependent on redox reactions and external ligands. By leveraging noncovalent interaction‐mediated disassembly and coordination microenvironment engineering, we achieve systematic control over the Cu(I) coordination geometry, progressively reducing the coordination number from 3 to mixed 3/2 and finally to purely 2, thereby creating highly unsaturated and accessible active sites. The resulting catalyst exhibits exceptional performance in copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) at room temperature, attributed to its high dispersion, optimized electronic structure, and intrinsic photothermal enhancement. This work provides atomic‐level insights into active‐site engineering and offers a versatile platform for energy‐efficient click chemistry under mild conditions.