1-(2,6-Dimethylphenyl)vinyl bromide | 74331-78-5

• 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: 1-(2,6-Dimethylphenyl)vinyl bromide
• 英文别名: α-(2,6-dimethylphenyl)vinyl bromide；2-(1-bromoethenyl)-1,3-dimethylbenzene；2-(1-Bromovinyl)-1,3-dimethylbenzene
• CAS: 74331-78-5
• 化学式: C₁₀H₁₁Br
• 分子量: 211.101
• InChiKey: AWFJPWTXIQCPJE-UHFFFAOYSA-N

物化性质

• 沸点：
  249.7±19.0 °C(Predicted)
• 密度：
  1.283±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  3.9
• 重原子数：
  11
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.2
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  1-(2,6-Dimethylphenyl)vinyl bromide 在 正丁基锂 、 碘 作用下， 以 正己烷 、 甲基叔丁基醚 、 乙醚 为溶剂， 反应 0.5h， 以31%的产率得到2,6-dimethyl-α-iodostyrene
  参考文献：
  名称：

  How Microsolvation Numbers at Li Control Aggregation Modes, sp²-Stereoinversion, and NMR Coupling Constants ²J_H,H of H₂C═C in α-(2,6-Dimethylphenyl)vinyllithium

  摘要：

  The title compound 4 is a trisolvated monomer 4&3THF in THF solution and dimerizes endothermically to form (4&THF)(2) with a strongly positive (!) dimerization entropy in toluene as the solvent. In the absence of electron-pair donor ligands, 4 aggregates (>dimer) in hydrocarbon solutions. These results followed from the C-13-alpha splitting patterns and the magnitudes of the one-bond C-13,Li-6 NMR coupling constants in combination with lithiation NMR shifts as secondary NMR criteria. The rate constants of cis/trans sp(2)-stereoinversion could be measured on the H-1 NMR time scale in THF, in which solvent the preinversion lifetime is 0.24 s at 25 degrees C. This inversion proceeds according to the pseudomonomolecular, ionic mechanism with the typical, strongly negative pseudoactivation entropy. In a different mechanism, the lifetimes are much longer at 25 degrees C for the dimer (4&t-BuOMe)(2) in toluene (ca. 2.5 min) and for donor-free, aggregated 4 in hexane solution (roughly 1 min). The olefinic interproton two-bond coupling constants (2)J(H,H) of the H2C=CLi part are proposed as an indicator of microsolvation at Li, because they were found to increase linearly with the "explicit" solvation of alpha-arylvinyllithiums by 0, 1, 2, and 3 electron-pair donor ligands.

  DOI：

  10.1021/acs.joc.5b00762
• 作为产物：
  描述：

  2,6-二甲基苯乙烯 在 18-冠醚-6 、 potassium tert-butylate 、 氢溴酸 、 溴 作用下， 以 氯仿 为溶剂， 生成 1-(2,6-Dimethylphenyl)vinyl bromide
  参考文献：
  名称：

  Dissociative ionization of aryl-substituted vinyl bromides in the gas phase: experimental and computational evidence for the formation of stable .alpha.-arylvinyl cations both by direct means and by spontaneous exothermic isomerization of unstable isomeric ions

  摘要：

  DOI：

  10.1021/ja00400a047

文献信息

• Alkenyl Bromides by Brominative Deoxygenation of Ketones in One or Two Steps
  作者：Ulrich Von Roman、Jakob Ruhdorfer、Rudolf Knorr

  DOI：10.1055/s-1993-25986

  日期：——

  The conversion of ketones into alkenyl bromides is accomplished in one or two steps by 2,2,2-tribromo-2,2-dihydro-1,3,2-benzodioxaphosphole or by the dibromomethyl methyl ether prepared therefrom. Investigations of the scope and limitations provide some hints for the preparative planning and improvement.

  通过使用2,2,2-三溴-2,2-二氢-1,3,2-苯并二氧磷杂环己烯或由此制备的二溴甲基甲醚，可以将酮转化为烯基溴，这一过程在一到两步内完成。对范畴和限制条件的研究为制备规划和改进提供了一些线索。
• Vinyl cation intermediates in solvolytic and electrophilic reactions. 1. Solvolysis of .alpha.-arylvinyl derivatives
  作者：Keith Yates、George Mandrapilias

  DOI：10.1021/jo01307a032

  日期：1980.9
• Kinetics of α-(2,6-Dimethylphenl)vinyllithium: How To Control Errors Caused by Inefficient Mixing with Pairs of Rapidly Competing Ketones
  作者：Rudolf Knorr、Monika Knittl、Claudia Behringer、Jakob Ruhdorfer、Petra Böhrer

  DOI：10.1021/acs.joc.6b02686

  日期：2017.3.17

  Kinetic studies are a suitable tool to disclose the role of tiny reagent fractions. The title compound 2 reacted in a kinetic reaction order of 0.5 (square root of its concentration) with an excess of the electrophiles ClSiMe3, 1-bromobutane (n-BuBr), or 1-iodobutane (n-BuI) at 32 degrees C in Et2O or in hydrocarbon solvents. This revealed that the tiny (NMR-invisible) amount of a deaggregated equilibrium component (presumably monomeric 2) was the reactive species, whereas the disolvated dimer 2 was only indirectly involved as a supply depot. Selectivity data (relative rate constants ?obs) were collected from competition experiments with the faster reactions of 2 in THF and the addition reactions of 2 to carbonyl compounds. This provided the rate sequences of Et2C=O > dicyclopropyl ketone > t-Bu-C(=O)-Ph > diisopropyl ketone >> t-Bu2C=O > ClSiMe3 > n-BuI > n-BuBr approximate to (bromomethyl)cyclopropane (but t-Bu2C=O < ClSiMe3 in THF only) and also of cyclopropanecarbaldehyde > acetone >= t-BuCH=O. It is suggested that a deceivingly depressed selectivity (1 < kappa(obs) < k(A)/k(B)), caused by inefficient microscopic mixing of a reagent X with two competing substrates A and B, may become evident toward zero deviation from the correlation line of the usual inverse (1/T) linear temperature dependence of ln ?obs.
• Knorr, Rudolf; Behringer, Claudia; Noeth, Heinrich, Chemische Berichte, 1997, vol. 130, # 5, p. 585 - 592
  作者：Knorr, Rudolf、Behringer, Claudia、Noeth, Heinrich、Schmidt, Martin、Lattke, Ernst、Raepple, Edith

  DOI：——

  日期：——
• Dissociative ionization of aryl-substituted vinyl bromides in the gas phase: experimental and computational evidence for the formation of stable .alpha.-arylvinyl cations both by direct means and by spontaneous exothermic isomerization of unstable isomeric ions
  作者：Yitzhak Apeloig、Wilfried Franke、Zvi Rappoport、Helmut Schwarz、Daniel Stahl

  DOI：10.1021/ja00400a047

  日期：1981.5