Ultrafast Conversion of CO <sub>2</sub> into Quinazoline-2,4(1 <i>H</i> ,3 <i>H</i> )-diones Catalyzed by a [Co <sub>3</sub> ] Cluster-Based Metal–Organic Framework at Room Temperature
Xinyuan Zhao, Le‐Yan Li, Xiang‐Shuai Li, Fang‐Yu Ren, Wen Wang, Xiang‐Yu Zhang, Jian Zhao, Sheng‐Li Hou, Yue Ma, Bin Zhao
Abstract
The conversion of CO 2 into quinazoline-2,4(1 H,3 H )-diones is a vital process in the pharmaceutical industry; however, developing efficient catalysts to realize ultrafast reaction rates remains challenging due to the complex reaction steps. Herein, the novel metal–organic framework {[(CH 3 ) 2 NH 2 ][Co 3 (μ 3 –OH)(BTB) 2 (BPT)]·4DMF·2H 2 O} n ( Z-1 ) was synthesized, exhibiting high solvent and thermal stability, and featuring asymmetric [Co 3 ]-clusters, abundant open metal sites, and nanocages. Remarkably, Z-1 catalyzed the reaction between CO 2 and 2-amino- N -methylbenzamide at an ultrafast rate, achieving a 92% yield of 3-methylquinazoline-2,4(1 H,3 H )-diones within 2 min at room temperature. Its turnover frequency (613 h –1 ) is the highest value recorded in all catalytic systems for synthesizing quinazoline-2,4(1 H,3 H )-diones. Additionally, Z-1 accommodated 16 diverse substrates and maintained a high yield over ten catalytic cycles. Mechanistic studies revealed that the [Co 3 ]-clusters effectively activated the amino group of substrates (the rate-determining step), while the thiadiazole moieties created alkaline microenvironments that enriched and activated CO 2 . Density functional theory calculations further confirmed that Z-1 effectively reduced the activation energy barrier of the rate-determining step, thereby accelerating the generation of the carbamate intermediate from CO 2 and 2-aminobenzamide. This work presents the first heterogeneous catalyst capable of efficiently catalyzing the reaction between 2-aminobenzamide and CO 2, providing new insights into the design of catalysts for the chemical fixation of CO 2 .