Catalytic carboxylation of sp ² and sp ³ C–H bonds with CO ₂ under atmospheric pressure conditions: an integrated experimental and theoretical study

The dramatic rise in CO₂ emissions from numerous anthropogenic sources is fundamentally disrupting the natural carbon cycle. Consequently, developing efficient, low-cost catalysts for effective carbon capture and utilization (CCU) as a C1 building block for the preparation of valuable chemicals and fuels will be a prominent step toward alleviating the growing atmospheric CO₂ concentration. Herein, we report the development of a two-dimensional (2D) covalent organic framework (Ag₃-TAPT-COF), constructed from an Ag(I)-based cyclic trinuclear complex (Ag₃-cluster) and a 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline (TAPT) linker. Ag₃-TAPT-COF is composed of a CO₂-philic nitrogen-rich triazine ring and catalytically active Ag₃ clusters (SBUs) highly exposed in one-dimensional (1D) channels of the framework, promoting efficient CO₂ fixation through C(sp²)-H and C(sp³)-H carboxylation, producing corresponding high-value carboxylic acids with significant biological relevance. This work introduces a sustainable strategy employing an Ag(I)-cluster-based catalytic system for the efficient transformation of CO₂ to significant compounds through the carboxylation of inert C(sp²)-H and C(sp³)-H bonds, producing important commodity compounds under mild conditions.