Carbon Dioxide Insertion into Group 9 and 10 Metal-Element σ Bonds
Carbon Dioxide Insertion into Group 9 and 10 Metal-Element σ Bonds
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DOI：
10.1021/acs.inorgchem.7b02315
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发表时间：
2017-11-20
影响因子：
4.6
通讯作者：
Heimann, Jessica E.
中科院分区：
文献类型：
--
作者：
Hazari, Nilay;Heimann, Jessica E.
二氧化碳（CO2）是一种有吸引力的原料，用于可持续地制备各种碳基商品化学品，因为它的高丰度，低成本和无毒。然而，CO2的高动力学和热力学稳定性意味着目前只有有限数量的实用催化系统用于将CO2转化为更有价值的化学品，并且需要在该领域继续研究。最终转化CO2的一种有希望的方法是首先将分子插入过渡金属元素σ键，如M-H，M-OR，M-NR2和M-CR3键，以形成M-OC（O）E（E = H，OR，NR2或CR3）类型的产物。CO2插入已经被证明了许多涉及过渡金属络合物的化学计量反应，但是在插入导致形成强M-O键的情况下，产物通常太稳定而不能进行进一步的转化。第9族和第10族过渡金属络合物（M = Ni、Pd、Pt、Co、Rh或Ir）形成相对弱的M-O键，因此，已经开发了许多第9族和第10族过渡金属催化剂，其中提出将CO2插入作为催化中的基本步骤。在这篇获奖文章中，我们总结了第9族和第10族过渡金属络合物，其中观察到CO2插入金属元素σ键形成M-OC（O）E型产物。通过比较不同类型的第9和10族金属元素σ键中的CO2插入反应，突出了机制的相似性和差异，并基于σ键中元素的亲核性描述了预测插入过程的速率决定步骤的一般趋势。虽然我们专注于化学计量的反应，相关的CO2插入催化反应也强调了整个文件。
Carbon dioxide (CO2) is an appealing feedstock for the sustainable preparation of a variety of carbon-based commodity chemicals because of its high abundance, low cost, and nontoxicity. The high :kinetic and thermodynamic stability of CO2, however, means that there are Currently only a limited number of practical catalytic systems for the conversion of CO2 into more valuable chemicals, and continued research in this area is required. One promising approach for the eventual transformation of CO2 is to initially insert the molecule into transition-metal element sigma bonds such as M-H, M-OR, M-NR2, and M-CR3 bonds to form products of the type M-OC(O)E (E = H, OR, NR2, or CR3). CO2 insertion has been demonstrated numerous, stoichiometric reactions involving transition-metal complexes, but in cases where insertion results in the formation of strong M-O bonds, the products are often too stable to undergo further transformations. Group 9 and 10 transition-metal complexes (M = Ni, Pd, Pt, Co, Rh, or Ir) form relatively weak M-O bonds, and as a consequence, a number of group 9 and 10 transition-metal catalysts in which CO2 insertion is proposed as an elementary step in catalysis have been developed. In this Award Article, we summarize group 9 and 10 transition-metal complexes in which CO2 insertion into a metal-element sigma bond to form a M-OC(O)E-type product has been observed. Mechanistic similarities and differences are highlighted by comparing CO2 insertion reactions in different types of group 9 and 10 metal-element sigma bonds, and a general trend for predicting the rate-determining step of the insertion process is described based on the nucleophilicity of the element in the sigma bond. Although we focus on stoichiometric reactivity, the relevance of CO2 insertion to catalytic reactions is also emphasized throughout the paper.