Ultrafast Conversion of CO 2 into Quinazoline-2,4(1 H ,3 H )-diones Catalyzed by a Co 3 Cluster-Based Metal–Organic Framework at Room Temperature

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.