Effects of NHC-Backbone Substitution on Efficiency in Ruthenium-Based Olefin Metathesis
Effects of NHC-Backbone Substitution on Efficiency in Ruthenium-Based Olefin Metathesis
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DOI：
10.1021/ja900067c
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发表时间：
2009-04-15
影响因子：
15
通讯作者：
Grubbs, Robert H.
中科院分区：
文献类型：
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作者：
Kuhn, Kevin M.;Bourg, Jean-Baptiste;Grubbs, Robert H.
制备了一系列具有不同骨架和n -芳基取代度的n -杂环羰基（NHC）配体的钌烯烃复分解催化剂。这些配合物通过C-H活化n -芳基表现出更强的抗分解能力，从而增加了催化剂的使用寿命。这项工作利用机器人技术来检查复分解中每种催化剂的活性和稳定性，为配体结构和提高效率之间的关系提供了见解。该机器人方法的发展也表明，在优化条件下，低至25 ppm的催化剂负载可以导致二乙基二烯丙二酸二乙基闭合环复分解的转化率达到100%。
A series of ruthenium olefin metathesis catalysts bearing N-heterocyclic carbene (NHC) ligands with varying degrees of backbone and N-aryl substitution have been prepared. These complexes show greater resistance to decomposition through C-H activation of the N-aryl group, resulting in increased catalyst lifetimes. This work has utilized robotic technology to examine the activity and stability of each catalyst in metathesis, providing insights into the relationship between ligand architecture and enhanced efficiency. The development of this robotic methodology has also shown that, under optimized conditions, catalyst loadings as low as 25 ppm can lead to 100% conversion in the ring-closing metathesis of diethyl diallylmalonate.