Cooperative CO 2 Scission by Anomalous Insertion into a Rh–Si Bond
Cooperative CO 2 Scission by Anomalous Insertion into a Rh–Si Bond
复制标题
通过反常插入RhâSi 键的协同CO 2 断裂
DOI：
10.1021/acs.organomet.9b00556
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发表时间：
2019
期刊：
影响因子：
2.8
通讯作者：
Taylor, Buck L.
中科院分区：
文献类型：
--
作者：
Whited, Matthew T.;Zhang, Jia;Donnell, Theodore M.;Eng, Vanessa H.;Peterson, Paul O.;Trenerry, Michael J.;Janzen, Daron E.;Taylor, Buck L.
钳型[P2 Si]Rh配合物具有铑-硅键的特征，通过两种不同的途径促进CO2的化学计量还原与Si-O键的形成：（a）氢化物转移到CO2，然后甲酸盐迁移到硅，或（B）在Rh-Si单元处完全切断C = O键，以提供具有硅氧化物和羰基配体的产物。实验和计算相结合的研究表明，后一个过程是通过将CO2异常插入到极化的Rhδ−-Siδ+键中而发生的，这一发现通过将反应性扩展到非螯合体系而得到证实。硅氧羰基产物可以通过与水或频哪醇硼烷反应进一步加工，得到结构不同的CO2还原产物。两者合计，这些结果表明金属/主基团键如何可以调整到直接迁移插入反应性。
Pincer-type [P2Si]Rh complexes featuring a rhodium–silicon bond are shown to facilitate well-defined stoichiometric reductions of CO2with Si–O bond formation by two different pathways: (a) hydride transfer to CO2followed by formate migration to silicon, or (b) complete scission of the C═O bond at the Rh–Si unit to afford a product with siloxide and carbonyl ligands. A combined experimental and computational study shows that the latter process occurs by anomalous insertion of CO2into the polarized Rhδ−–Siδ+bond, a finding that is confirmed by extending the reactivity to an unchelated system. The siloxide carbonyl product can be further elaborated by reaction with water or pinacolborane to give structurally distinct CO2reduction products. Taken together, these results demonstrate how metal/main-group bonds can be tuned to direct migratory insertion reactivity.