"Synergistic effects of two Si-H groups and a metal center" in transition metal-catalyzed hydrosilylation of unsaturated molecules: A mechanistic study of the RhCl(PPh3)3-catalyzed hydrosilylation of ketones with 1,2-bis(dimethylsilyl)benzene
"Synergistic effects of two Si-H groups and a metal center" in transition metal-catalyzed hydrosilylation of unsaturated molecules: A mechanistic study of the RhCl(PPh3)3-catalyzed hydrosilylation of ketones with 1,2-bis(dimethylsilyl)benzene
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DOI：
10.1021/om800151w
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发表时间：
2008-06
期刊：
影响因子：
2.8
通讯作者：
Y. Sunada;Y. Fujimura;H. Nagashima
中科院分区：
文献类型：
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作者：
Y. Sunada;Y. Fujimura;H. Nagashima
以1，2-双（二甲基硅基）苯为原料，分别与RhCl（PPh 3）3和Rh（H）（PPh 3）4反应，合成了三种铑二硅杂环戊烯配合物，并讨论了它们对丙酮硅氢加成反应的催化作用。铑前体RhCl（PPh 3）3或Rh（H）（PPh 3）4与1，2-双（二甲基甲硅烷基）苯的反应得到一种不稳定的具有铑二硅杂环戊烯骨架的Rh（V）-三氢化物物种Rh（Me 2SiC 6 H4 SiMe 2）（H）3（PPh 3）2（1）作为初级产物，其通过1，2-双（二甲基甲硅烷基）苯与铑中心的双氧化加成形成。络合物1在浓缩时消除H2以定量地形成Rh（III）-单氢化物络合物Rh（SiMe 2C 6 H4 SiMe 2）（H）（PPh 3）2（2）。2与1，2-双（二甲基硅基）苯进一步氧化加成得到Rh（III）-三硅基配合物Rh（Me 2SiC 6 H4 SiMe 2）（η1-HSiMe 2C 6 H4 SiMe 2）（PPh 3）（3），其中Si−H键与Rh（III）中心之间存在agostic相互作用。从1中消除H2是可逆的，并且最有效的制备方法是...
Three rhodadisilacyclopentene complexes are synthesized by the reaction of 1,2-bis(dimethylsilyl)benzene with RhCl(PPh3)3 or Rh(H)(PPh3)4, and their contributions to the catalytic hydrosilylation of acetone are discussed. Treatment of the rhodium precursor RhCl(PPh3)3 or Rh(H)(PPh3)4 with 1,2-bis(dimethylsilyl)benzene affords an unstable Rh(V)-trihydride species having a rhodadisilacyclopentene skeleton, Rh(Me2SiC6H4SiMe2)(H)3(PPh3)2 (1), as a primary product, which is formed by double oxidative addition of 1,2-bis(dimethylsilyl)benzene to the rhodium center. The complex 1 eliminates H2 upon concentration to quantitatively form a Rh(III)-monohydride complex, Rh(SiMe2C6H4SiMe2)(H)(PPh3)2 (2). Further oxidative addition of 1,2-bis(dimethylsilyl)benzene to 2 gives a Rh(III)-trisilyl complex, Rh(Me2SiC6H4SiMe2)(η1-HSiMe2C6H4SiMe2)(PPh3) (3), in which there is an agostic interaction between the Si−H bond and the Rh(III) center. Elimination of H2 from 1 is reversible, and the most effective method for preparing...