In Situ Generation of an N-Heterocyclic Carbene Functionalized Metal-Organic Framework by Postsynthetic Ligand Exchange: Efficient and Selective Hydrosilylation of CO2
In Situ Generation of an N-Heterocyclic Carbene Functionalized Metal-Organic Framework by Postsynthetic Ligand Exchange: Efficient and Selective Hydrosilylation of CO2
复制标题
通过后合成配体交换原位生成 N-杂环卡宾功能化金属有机框架：CO2 的高效选择性硅氢加成
DOI：
10.1002/anie.201813064
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Fei Honghan
中科院分区：
文献类型：
--
作者：
Zhang Xu;Sun Jiao;Wei Guangfeng;Liu Zhipan;Yang Huimin;Wang Kaimin;Fei Honghan
本文报道的金属有机骨架（MOF）催化剂在环境条件下实现了二氧化碳到甲醇的转化。MOF是一个罕见的含有不含金属的N杂环碳（NHC）基团的例子，其安装使用原位生成策略，包括通过合成后配体交换将咪唑溴基连接剂结合到MOF中。重要的是，所得到的NHC功能化MOF是第一个能够从硅烷到二氧化碳进行定量氢转移的催化剂，从而实现定量（bbb99 %）甲醇收率。密度泛函理论计算表明，mof中NHC位点的高催化活性归因于NHC -硅烷加合物形成的反应途径的反应势垒降低。此外，MOF‐固定化NHC催化剂在没有碱基活化的情况下，可以达到8个循环，并且对所需的硅基甲氧基产物具有很高的选择性。
The reported metal–organic framework (MOF) catalyst realizes CO2to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO2, thus achieving quantitative (>99 %) methanol yield. Density‐functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product.