Redistribution of Trialkyl Silanes Catalyzed by Iridium Silyl Complexes
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- 作者：Sehoon Park ; Bong Gon Kim ; Inigo G枚ttker-Schnetmann ; Maurice Brookhart
- 刊名：ACS Catalysis
- 出版年：2012
- 出版时间：February 3, 2012
- 年：2012
- 卷：2
- 期：2
- 页码：307-316
- 全文大小：514K
- 年卷期：v.2,no.2(February 3, 2012)
- ISSN：2155-5435
文摘
[Ir(COE)2Cl]2 reacts with Et3SiH at 23 掳C to form a binuclear iridium complex (Et3Si)2(H)2Ir(渭-Cl)2Ir(H)2(SiEt3)2, 1. Complex 1 reacts further with Et3SiH at 60 掳C to form a second binuclear iridium complex, Et3Si(H)2Ir(渭-SiEt2)2Ir(H)2SiEt3, 2, containing bridging Et2Si groups. Activation of 2 with H2 produces trace quantities of a very highly reactive but unobservable species which rapidly and efficiently catalyzes alkyl redistribution reactions of silanes, RR鈥睷鈥砈iH. D2 and silane exchange experiments establish reactivity features of both 2 and the reactive intermediate. The intermediate cannot be observed, but it is likely a monomeric iridium silyl silylene complex that catalyzes alkyl scrambling via silane exchanges coupled with 1,3-alkyl migrations between silicon centers. DFT calculations support such a mechanism.