Disilametallacyclic chemistry for efficient catalysis
Disilametallacyclic chemistry for efficient catalysis
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用于高效催化的二硅金属环化学
DOI：
10.1039/c7dt01275f
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Sunada;Y.; Nagashima;H.
本文讨论了二硅金属环化学的两个新特征，它们有助于有机合成中高效催化反应的发展。第一个是羰基化合物的氢硅烷还原中的二硅金属环中间体。对二硅铂环的实验和理论研究表明，通过 1,2-双（二甲基甲硅烷基）苯氧化加成生成的 H2Pt(IV)Si2 物种表现为高反应性氢化物，可将酰胺还原为胺。这种通过二硅金属环中间体的机制解释了在其他过渡金属催化下，α,ω-双功能氢硅烷能够有效地还原羰基化合物。第二种是通过二硅铁环或二硅钌环络合物作为催化剂前体对烯烃进行氢化。 DFT计算提出了一种不涉及传统的H2氧化加成的新机制，其中H-H键的活化发生在二硅金属环中间体的金属-硅键中。二硅金属环中间体通过这种 σ-CAM（σ-复合辅助机制）类型的机制有助于有效的催化反应。
This article discusses two new features of disilametallacyclic chemistry that contribute to the development of efficient catalytic reactions in organic synthesis. The first is disilametallacyclic intermediates in the hydrosilane reduction of carbonyl compounds. Experimental and theoretical studies on disilaplatinacycles suggested that the H2Pt(IV)Si2 species generated by oxidative addition of 1,2-bis(dimethylsilyl)benzene behaves as a highly reactive hydride to reduce amides to amines. This mechanism via disilametallacyclic intermediates explains the efficient hydrosilane reduction of carbonyl compounds with α,ω-bifunctional hydrosilanes catalyzed by other transition metals. The second is hydrogenation of alkenes by disilaferra- or disilaruthenacyclic complexes as catalyst precursors. A new mechanism not involving the conventional oxidative addition of H2 was suggested from DFT calculations, in which activation of the H–H bond occurs in the metal–silicon bond of the disilametallacyclic intermediate. Disilametallacyclic intermediates contribute to efficient catalytic reactions through this σ-CAM (σ-complex assisted mechanism) type mechanism.