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Highly Efficient Conversion of Propargylic Amines and CO2 Catalyzed by Noble-Metal-Free [Zn116] Nanocages |
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| Authors: | Chun-Shuai Cao Shu-Mei Xia Zhen-Jun Song Hang Xu Ying Shi Prof Liang-Nian He Prof Peng Cheng Prof Bin Zhao |
| Institution: | 1. Key Laboratory of Advanced Energy Material Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071 China
College of Environmental Science and Engineering, Nankai University, Tianjin, 300350 China These authors contributed equally to this work.;2. State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071 China These authors contributed equally to this work.;3. Key Laboratory of Advanced Energy Material Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071 China These authors contributed equally to this work.;4. Key Laboratory of Advanced Energy Material Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071 China;5. State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071 China |
| Abstract: | The reaction of propargylic amines and CO2 can provide high-value-added chemical products. However, most of catalysts in such reactions employ noble metals to obtain high yield, and it is important to seek eco-friendly noble-metal-free MOFs catalysts. Here, a giant and lantern-like Zn116] nanocage in zinc-tetrazole 3D framework Zn22(Trz)8(OH)12(H2O)9?8 H2O]n Trz=(C4N12O)4? ( 1 ) was obtained and structurally characterized. It consists of six Zn14O21] clusters and eight Zn4O4] clusters. To our knowledge, this is the highest-nuclearity nanocages constructed by Zn-clusters as building blocks to date. Importantly, catalytic investigations reveal that 1 can efficiently catalyze the cycloaddition of propargylic amines with CO2, exclusively affording various 2-oxazolidinones under mild conditions. It is the first eco-friendly noble-metal-free MOFs catalyst for the cyclization of propargylic amines with CO2. DFT calculations uncover that ZnII ions can efficiently activate both C≡C bonds of propargylic amines and CO2 by coordination interaction. NMR and FTIR spectroscopy further prove that Zn-clusters play an important role in activating C≡C bonds of propargylic amines. Furthermore, the electronic properties of related reactants, intermediates and products can help to understand the basic reaction mechanism and crucial role of catalyst 1 . |
| Keywords: | CO2 conversion metal–organic frameworks nanocages noble-metal-free catalysts propargylic amines |