Highly Efficient Conversion of Propargylic Amines and CO2 Catalyzed by Noble-Metal-Free [Zn116] Nanocages
Highly Efficient Conversion of Propargylic Amines and CO2 Catalyzed by Noble-Metal-Free [Zn116] Nanocages
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DOI：
10.1002/anie.201914596
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发表时间：
2020-03-20
影响因子：
16.6
通讯作者：
Zhao, Bin
中科院分区：
文献类型：
--
作者：
Cao, Chun-Shuai;Xia, Shu-Mei;Zhao, Bin
炔丙胺与CO2的反应可以提供高附加值的化工产品。然而，在这些反应中，大多数催化剂使用贵金属以获得高收率，并且重要的是寻求环境友好的无贵金属的MOFs催化剂。在此，获得了一个巨大的灯笼状的[Zn-116]纳米笼，其在锌-四唑三维框架[Zn-22（Trz）（8）（OH）（12）（H2O）（9.8）H2O]（n）Trz =（C4 N12 O）（4-）（1）中，并进行了结构表征。它由6个[Zn 14021]团簇和8个[Zn 4 O 4]团簇组成。据我们所知，这是迄今为止由锌团簇作为构建块构建的最高核密度的纳米笼。重要的是，催化研究表明，1可以有效地催化炔丙胺与CO2的环加成反应，在温和的条件下专门提供各种2-恶唑烷酮。它是第一个环保的无贵金属MOFs催化剂，用于炔丙胺与CO2的环化反应。密度泛函理论计算表明，ZnII离子能通过配位作用有效地活化炔丙胺的C-C键和CO。NMR和FTIR光谱进一步证明了Zn原子簇在活化炔丙胺的C-C键中起着重要作用。此外，相关反应物、中间体和产物的电子性质有助于理解基本反应机理和催化剂1的关键作用。
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-metalfree MOFs catalysts. Here, a giant and lantern-like [Zn-116] nanocage in zinc-tetrazole 3D framework [Zn-22(Trz)(8)(OH)(12)(H2O)(9.8) H2O](n) Trz = (C4N12O)(4-) (1) was obtained and structurally characterized. It consists of six [Zn14021 clusters and eight [Zn4O4] clusters. To our knowledge, this is the highestnuclearity 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 ofpropargylic amines and CO, by coordination interaction. NMR and FTIR spectroscopy further prove that Zn-clusters play an important role in activating C C bonds ofpropargylic 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.