Theoretical Study of Reactivity of Ge(II)-hydride Compound: Comparison with Rh(I)-Hydride Complex and Prediction of Full Catalytic Cycle by Ge(II)-hydride.
The reaction of a Ge(II) hydride compound HC{CMeArN}GeH (Ar = 2,6-iPrCH) 1 with 2,2,2-trifluoroacetophenone (CFPhCO) is theoretically investigated with density functional theory and spin-component-scaled second-order Møller–Plesset methods. This reaction easily occurs with moderate activation barrie...
| Publicado en: | Journal of the American Chemical Society Vol. 135; no. 24; pp. 8955 - 8966 |
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| Autores principales: | , |
| Formato: | Artículo |
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American Chemical Society
6/19/2013
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=89498671&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 89498671 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 6/19/2013 vid: 135 iid: 24 pid: 997 pub: American Chemical Society artinfo: ui: 89498671 10.1021/ja402039b ppf: 8955 ppct: 11 formats: tig: atl: Theoretical Study of Reactivity of Ge(II)-hydride Compound: Comparison with Rh(I)-Hydride Complex and Prediction of Full Catalytic Cycle by Ge(II)-hydride. aug: au: Nozomi Takagi Shigeyoshi Sakaki affil: Fukui Institute for Fundamental Chemistry, Kyoto University Takano, Nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103, Japan su: Germanium Hydrides Reactivity (Chemistry) Density functional theory Exothermic reactions Activation energy Ketones Hydrogenation sug: subj: Germanium Hydrides Reactivity (Chemistry) Density functional theory Exothermic reactions Activation energy Ketones Hydrogenation ab: The reaction of a Ge(II) hydride compound HC{CMeArN}GeH (Ar = 2,6-iPrCH) 1 with 2,2,2-trifluoroacetophenone (CFPhCO) is theoretically investigated with density functional theory and spin-component-scaled second-order Møller–Plesset methods. This reaction easily occurs with moderate activation barrier and considerably large exothermicity, to afford a Ge(II) alkoxide 2 through a four-membered transition state. In the transition state, the charge transfer from the Ge–H σ-bonding molecular orbital (MO) to the C=O π*-antibonding MO of CFPhCO plays an important role. Acetone ((CH)CO) and benzophenone (PhCO) are not reactive for 1, because their π*-antibonding MOs exist at higher energy than that of CFPhCO. Though 2 is easily formed, the catalytic hydrogenation of CFPhCO by 1 is difficult because the reaction of 2 with a dihydrogen molecule needs a large activation energy. On the other hand, our calculations clearly show that the catalytic hydrogenation of ketone by cis-RhH(PPh)4 easily occurs, as expected. The comparison of catalytic cycle between 1 and 4 suggests that the strong Ge–O bond of 2 is the reason of the very large activation energy for the hydrogenation by 1. To overcome this defect, we investigated various reagents and found that the catalytic cycle can be completed with the use of SiFH. The product is silylether CFPhCHOSiF, which is equivalent to alcohol because it easily undergoes hydrolysis to afford CFPhCHOH. The similar catalytic cycles are also theoretically predicted for hydrosilylations of CO and imine. This is the first theoretical prediction of the full catalytic cycle with a heavier main-group element compound. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2013 holdings: @attributes: islocal: N |
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