Tetrachlorohydroquinone mono(trimethylsilyl) ether

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: Tetrachlorohydroquinone mono(trimethylsilyl) ether
• 英文别名: tetrachlorohydroquinone；2,3,5,6-Tetrachloro-4-trimethylsilyloxyphenol
• 化学式: C₉H₁₀Cl₄O₂Si
• 分子量: 320.075
• InChiKey: YAXLLMKXBMITCR-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.22
• 重原子数：
  16
• 可旋转键数：
  2
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  29.5
• 氢给体数：
  1
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  四氯氰醌 、 N,O-双(三甲基硅烷基)三氟乙酰胺 以 四氢呋喃 为溶剂， 生成 Tetrachlorohydroquinone mono(trimethylsilyl) ether
  参考文献：
  名称：

  Chloranil-Sensitized Photolysis of Benzyltrimethylsilanes. Solvent Effect on the Competition between Carbon-Hydrogen and Carbon-Silicon Bond Cleavage

  摘要：

  A steady state and laser flash photolysis study of the chloranil (CA)-sensitized oxidation of benzyltrimethylsilane (BTS) and (4-methoxybenzyl)trimethylsilane (MBTS) in different solvents (benzene, CH2Cl2, and MeCN) has been carried out. In benzene, BTS reacts with (3)CA* to give exclusively alpha-substituted benzyltrimethylsilane, whereas with MBTS the alpha-substituted silane is formed together with benzylic desilylation products. The latter situation also holds in CH2Cl2 for BTS. Only desilylation products are obtained from MBTS in CH2Cl2 and from both BTS and MBTS in MeCN. Higher quantum yields in the reactions with BTS than in those with MBTS have been observed in benzene and CH2Cl2. In MeCN, no significant change in quantum yield has been observed on going from BTS to MBTS. In MeCN with both BTS and MBTS and in CH2Cl2 with MBTS, the laser photolysis experiments have shown evidence for the formation of transients which can be attributed to MBTS(.+) and CA(.-) (MBTS in MeCN and CH2Cl2) and to CA(.-) (BTS in MeCN). This indicates that quenching of (3)CA* has taken place via an electron transfer process. Once formed, both BTS.+ and MBTS(.+) undergo exclusive C-Si bond cleavage. In CH2Cl2, this reaction is promoted by CA(.-), and accordingly, MBTS(.+) decays by a second-order kinetics. In MeCN, MBTS(.+) decays by a first-order kinetics and desilylation is promoted by the solvent itself. The same holds for BTS.+ as the decay reaction of this cation radical in MeCN appears much faster than that of CA(.-). In fact, only the transient assigned to the latter species has been observed in the laser photolysis experiments. A different situation has been found for both MBTS and BTS in benzene and BTS in CH2Cl2, where quenching of (3)CA* occurs via a partial charge transfer (CT) triplet complex. The reversible formation of this complex with MBTS in benzene is clearly indicated by the dependence of the observed rate constant for 3CA* quenching on the substrate concentration, which has allowed the association constant for the complex(ca. 400 M(-1)) to be determined. With BTS in benzene and CH2Cl2, the formation of the CT triplet complex is irreversible and rate determining, and the main evidence in this respect comes from the absence of a sizable deuterium kinetic isotope effect for the 3CA* quenching rate. With BTS in benzene, the CT complex undergoes C-H bond cleavage as the exclusive chemical reaction. With MBTS in benzene and BTS in CH2Cl2, both C-H and C-Si bond cleavages take place, and it is suggested that the cleavage of the latter bond requires more transfer of charge in the complex than the cleavage of the C-H bond. Alternatively, in CH2Cl2, the CT complex might evolve in part to a solvent-separated radical ion pair, exclusively leading to the C-Si bond cleavage products. The above results have also allowed an assessment of the scope of the benzyltrimethylsilane probe to detect electron transfer mechanisms.

  DOI：

  10.1021/jo00129a044

文献信息

• Photoinduced electron transfer from enol silyl ethers to quinone. Part 1. Pronounced effects of solvent polarity and added salt on the formation of α-enones
  作者：T. Michael Bockman、D. Shukla、Jay K. Kochi

  DOI：10.1039/p29960001623

  日期：——

  The enol silyl ethers (ESE) of various ketones are efficiently oxidized to the corresponding α,β-unsaturated enones (E) when a dichloromethane solution containing equimolar amounts of chloranil is irradiated with filtered light (λexc > 380 nm). The 1 : 1 adduct (A) of enol silyl ether and quinone is a byproduct, the structure of which is established by X-ray crystallography. Solvent polarity and added

  各种酮的烯醇甲硅烷基醚（ESE）被有效地氧化成相应的α，β不饱和烯酮（E）当将含有等摩尔量的氯醌的二氯甲烷溶液照射过滤的光（λ EXC > 380纳米）。烯醇甲硅烷基醚和醌的1：1加合物（A）是副产物，其结构通过X射线晶体学确定。溶剂极性和添加的盐在建立E与A之间的产物分布中起着重要作用。这种中等作用，再加上由2-甲基环己酮甲硅烷基化衍生的动力学-热力学异构体的现成异构化，指出了该化合物的阳离子基团。烯醇甲硅烷基醚（ESE˙ +）作为反应性中间体。讨论了一种自由基-离子对机制，涉及光活化的氯腈对烯醇甲硅烷基醚的快速单电子氧化。
• Bockman, T. Michael; Kochi, Jay K., Journal of the Chemical Society. Perkin transactions II, 1996, # 8, p. 1633 - 1644
  作者：Bockman, T. Michael、Kochi, Jay K.

  DOI：——

  日期：——
• Chloranil-Sensitized Photolysis of Benzyltrimethylsilanes. Solvent Effect on the Competition between Carbon-Hydrogen and Carbon-Silicon Bond Cleavage
  作者：Enrico Baciocchi、Tiziana Del Giacco、Fausto Elisei、Marcella Ioele

  DOI：10.1021/jo00129a044

  日期：1995.12

  A steady state and laser flash photolysis study of the chloranil (CA)-sensitized oxidation of benzyltrimethylsilane (BTS) and (4-methoxybenzyl)trimethylsilane (MBTS) in different solvents (benzene, CH2Cl2, and MeCN) has been carried out. In benzene, BTS reacts with (3)CA* to give exclusively alpha-substituted benzyltrimethylsilane, whereas with MBTS the alpha-substituted silane is formed together with benzylic desilylation products. The latter situation also holds in CH2Cl2 for BTS. Only desilylation products are obtained from MBTS in CH2Cl2 and from both BTS and MBTS in MeCN. Higher quantum yields in the reactions with BTS than in those with MBTS have been observed in benzene and CH2Cl2. In MeCN, no significant change in quantum yield has been observed on going from BTS to MBTS. In MeCN with both BTS and MBTS and in CH2Cl2 with MBTS, the laser photolysis experiments have shown evidence for the formation of transients which can be attributed to MBTS(.+) and CA(.-) (MBTS in MeCN and CH2Cl2) and to CA(.-) (BTS in MeCN). This indicates that quenching of (3)CA* has taken place via an electron transfer process. Once formed, both BTS.+ and MBTS(.+) undergo exclusive C-Si bond cleavage. In CH2Cl2, this reaction is promoted by CA(.-), and accordingly, MBTS(.+) decays by a second-order kinetics. In MeCN, MBTS(.+) decays by a first-order kinetics and desilylation is promoted by the solvent itself. The same holds for BTS.+ as the decay reaction of this cation radical in MeCN appears much faster than that of CA(.-). In fact, only the transient assigned to the latter species has been observed in the laser photolysis experiments. A different situation has been found for both MBTS and BTS in benzene and BTS in CH2Cl2, where quenching of (3)CA* occurs via a partial charge transfer (CT) triplet complex. The reversible formation of this complex with MBTS in benzene is clearly indicated by the dependence of the observed rate constant for 3CA* quenching on the substrate concentration, which has allowed the association constant for the complex(ca. 400 M(-1)) to be determined. With BTS in benzene and CH2Cl2, the formation of the CT triplet complex is irreversible and rate determining, and the main evidence in this respect comes from the absence of a sizable deuterium kinetic isotope effect for the 3CA* quenching rate. With BTS in benzene, the CT complex undergoes C-H bond cleavage as the exclusive chemical reaction. With MBTS in benzene and BTS in CH2Cl2, both C-H and C-Si bond cleavages take place, and it is suggested that the cleavage of the latter bond requires more transfer of charge in the complex than the cleavage of the C-H bond. Alternatively, in CH2Cl2, the CT complex might evolve in part to a solvent-separated radical ion pair, exclusively leading to the C-Si bond cleavage products. The above results have also allowed an assessment of the scope of the benzyltrimethylsilane probe to detect electron transfer mechanisms.