Cage-Confined CuO Nanoparticles: Unlocking Site-Selective Catalysis for Borylation of α,β-Unsaturated Conjugated Compounds

The borylation of α,β-unsaturated carbonyl compounds is pivotal for constructing multifunctional organoboron intermediates in pharmaceuticals and materials. Here, the study reports CuO@COP1-T, a novel catalyst integrating CuO nanoparticles (NPs) within a covalent organic porous cage (COP1-T), which achieves unprecedented site-selectivity in the borylation of α,β-unsaturated conjugated compounds. Experimental results demonstrate CuO@COP1-T exhibits 100% monoboration selectivity for trans-dibenzylideneacetone, surpassing unsupported CuO@NPs (8%). Molecular dynamics (MD) simulations reveal the 1.2 nm triangular cage pores enforce selectivity via geometric matching with reaction intermediates. Optimization of reaction conditions clarifies the impacts of methanol amount, solvent type, and base addition. The catalyst retains >95% activity over five cycles, showcasing robust stability. This work establishes a synergistic platform where COP1-T stabilizes CuO NPs while creating a confined microenvironment to enforce spatial confinement effects, providing a rational design strategy for confined-metal catalysts in organoboron chemistry.