Efficient and Reusable Metal–Organic Framework Catalysts for Carboxylative Cyclization of Propargylamines with Carbon Dioxide

Abstract Carbon dioxide (CO 2 ) capture and transformation are important for decreasing the concentration of atmospheric CO 2 . To effectively capture CO 2 and further fix it into valuable chemical products, functionalized dynamic metal–organic frameworks (MOFs) have been utilized not only because of their inherent cavity for accommodating CO 2 but also owing to their reversible structural transformations in response to external stimuli for regulating the reaction. Herein, we report a dynamic and functional MOF [Cd 3 (L) 2 (BDC) 3 ] 2 ⋅ 16 DMF ( MOF‐1 a ; DMF= N , N ‐dimethylformamide) achieved by reaction of the amino tripodal imidazole ligand N 1 ‐(4‐(1 H ‐imidazol‐1‐yl)benzyl)‐ N 1 ‐ (2‐aminoethyl)ethane‐1,2‐diamine (L) and 1,4‐benzenedicarboxylic acid (H 2 BDC) with cadmium salt. MOF‐1 a not only shows unprecedented high catalytic activity [initial turnover number (TON) up to 9300] and broad substrate scope for the carboxylative cyclization of propargylamines with CO 2 , but also can be switched on and off upon reversible structural transformation owing to its dynamic five‐fold interpenetrating structure. Further studies demonstrate that MOF‐1 a shows selective catalytic properties depending on the size of substrates, similarly to sophisticated biological systems.