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Effective CO2transformations hold essential significance for carbon neutrality and sustainable energy development. Carboxylative cyclization of propargylic amines with CO2serves as an atom-economic reaction to afford oxazolidinones, showing broad applications in organic synthesis and pharmaceutical fields. However, most catalysts involved noble metals, exhibited low efficiency, or required large amounts of base. Hence, it is imperative to explore alternative noble-metal-free catalysts in order to achieve efficient conversion while minimizing the use of additives. Herein, a novel nanopore-based Cu(II)–organic framework (1) based on a new imidazole carboxylic ligand was successfully constructed and exhibited excellent stability. Catalytic investigations revealed that the combination of 1with 1,4-diaza[2.2.2]bicyclooctane (DABCO) efficiently catalyzed the carboxylative cyclization of propargylic amines with CO2, achieving turnover numbers of 142 based on the catalyst and 7.1 based on DABCO. 1as a heterogeneous catalyst maintained high catalytic performance even after being reused at least 5 cycles, with its structure remaining stable. The strong activation of Cu(II) cluster nodes of catalyst 1toward −NH– groups within organic substrates, as demonstrated by mechanism experiments, along with excellent CO2adsorption performance and the presence of regular 1D channels, synergistically facilitates the reaction rate. This research presents the first instance of a Cu(II)–organic framework achieving this cyclization reaction, offering wide prospects for novel catalyst design and CO2utilization.

Efficient and multiple CO2utilization into high-value-added chemicals holds significant importance in carbon neutrality and industry production. However, most catalysis systems generally exhibit only one type of CO2transformation with the efficiency to be improved. The restricted abundance of active catalytic sites or an inefficient utilization rate of these sites results in the constraint. Consequently, we designed and constructed two metal hydrogen-bonded organic frameworks (M-HOFs) {[M3(L3–)2(H2O)10]·2H2O}n(M = Co (1), Ni (2); L = 1-(4-carboxyphenyl)-1H-pyrazole-3,5-dicarboxylic acid) in this research. 1and 2are well-characterized, and both show excellent stability. The networks connected by multiple hydrogen bonds enhance the structural flexibility and create accessible Lewis acidic sites, promoting interactions between the substrates and catalytic centers. This enhancement facilitates efficient catalysis for two types of CO2transformations, encompassing both cycloaddition reactions with epoxides and aziridines to afford cyclic carbonates and oxazolidinones. The catalytic activities (TON/TOF) are superior compared with those of most other catalysts. These heterogeneous catalysts still exhibited high performance after being reused several times. Mechanistic studies indicated intense interactions between the metal sites and substrates, demonstrating the reason for efficient catalysis. This marks the first instance on M-HOFs efficiently catalyzing two types of CO2conversions, finding important significance for catalyst design and CO2utilization.