SiMes2-THF complex | 112400-75-6

• 英文名称: SiMes2-THF complex
• CAS: 112400-75-6
• 化学式: C₂₂H₃₀OSi
• 分子量: 338.565
• InChiKey: GAOVSPCWXSHHON-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
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• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  四氢呋喃 、 2,2-dimesitylhexamethyltrisilane 以 正己烷 为溶剂， 生成 SiMes2-THF complex
  参考文献：
  名称：

  Fast Kinetics Study of the Reactions of Transient Silylenes with Alcohols. Direct Detection of Silylene−Alcohol Complexes in Solution

  摘要：

  The kinetic behavior of dimethyl-, diphenyl-, and dimesitylsilylene in hexanes solution in the presence of methanol (MeOH), tert-butanol (t-BuOH), and the respective O-deuterated isotopomers has been studied, with the goal of elucidating a detailed mechanism for the formal O-H insertion reaction of transient silylenes with alcohols in solution. The data are in all cases consistent with a mechanism involving the intermediacy off lie corresponding silylene-alcohol Lewis acid-base complexes, which have been detected directly for each of the SiMe2-ROL and SiPh2-ROL (L = H or D) systems that were studied. Complexation proceeds effectively irreversibly (K-cq >= 2 x 10(5) M-1) and at close to the diffusion-controlled rate in these cases. I it contrast, the kinetic and spectroscopic behavior observed for SiMes(2) in the presence of these alcohols indicates the SiMes(2)-ROL complexes are involved its steady-state intermediates. Formed reversibly and 10-100 times more Slowly than is the case with SiMe2 and SiPh2 Product formation from the silylene-alcohol complexes is shown to proceed via catalytic proton transfer by it second molecule of alcohol, the rate of which exceeds that of unimolecular intracomplex H-migration in all cases, even at submillimolar alcohol concentrations. The catalytic rate constants range from 10(9) to 10(10) M-1 s(-1) for the SiMe2-ROH and SiPh2-ROH complexes, sufficiently fast that the isotope effect ranges from ca. 2.5 to close to unity for all but the SiPh2-t-BuOL complex, where it is remarkably large (k(HH)/k(DD)= 10.8 +/- 2.4). The value is consistent with a mechanism for catalysis involving double proton transfer within it cyclic five-membered transition state. The isotope effects on the ratio of the rate Constants for Catalytic proton transfer and dissociation of the SiMes(2)-MeOH and SiMes(2),-t-BuOH complexes suggest that a different mechanism for catalytic proton transfer is involved in the case of the sterically hindered diarylsilylene.

  DOI：

  10.1021/om9009747