((1S,4R)-3-Bromo-4-methoxy-cyclopent-2-enyloxy)-tert-butyl-dimethyl-silane | 188438-23-5

• 分子结构分类: 有机化合物 - 有机金属化合物 - 有机类金属化合物
• 英文名称: ((1S,4R)-3-Bromo-4-methoxy-cyclopent-2-enyloxy)-tert-butyl-dimethyl-silane
• 英文别名: {[(1S,4R)-3-Bromo-4-methoxy-2-cyclopenten-1-YL]oxy}(tert-butyl)dimethylsilane；[(1S,4R)-3-bromo-4-methoxycyclopent-2-en-1-yl]oxy-tert-butyl-dimethylsilane
• CAS: 188438-23-5
• 化学式: C₁₂H₂₃BrO₂Si
• 分子量: 307.303
• InChiKey: FNPYTMVWCQCQKK-MWLCHTKSSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.07
• 重原子数：
  16
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  ((1S,4R)-3-Bromo-4-methoxy-cyclopent-2-enyloxy)-tert-butyl-dimethyl-silane 在 四丁基氟化铵 、 sodium hydride 作用下， 以 四氢呋喃 为溶剂， 反应 3.5h， 生成 (3S,5R)-1-bromo-3,5-dimethoxycyclopentene
  参考文献：
  名称：

  Enhanced Channeling of the Squarate Cascade through the Dianionic Oxy-Cope Option. Oxy Substitution Markedly Augments Syn Delivery of the Second Alkenyllithium

  摘要：

  A general means for enhancing the extent to which squarate esters enter into cascade processes involving a dianionic oxy-Cope rearrangement as the key step is presented. Adoption of this sigmatropic process requires that the two alkenyllithium reagents being introduced add cis to each other, a kinetic bias which can be realized simply by the proper incorporation of ethereal oxygen substituents in the first organometallic reagent. Structural reorganization occurs via boat-like transition states such that stereoinduction manifests itself with high fidelity.

  DOI：

  10.1021/ja964140d
• 作为产物：
  描述：

  (4S)-(-)-2-bromo-4-<(tert-butyldimethylsilyl)oxy>2-cyclopentenone 在 sodium tetrahydroborate 、 cerium(III) chloride 、 sodium hydride 作用下， 以 四氢呋喃 、 甲醇 为溶剂， 反应 10.0h， 生成 ((1S,4R)-3-Bromo-4-methoxy-cyclopent-2-enyloxy)-tert-butyl-dimethyl-silane
  参考文献：
  名称：

  Sensitivity of Substitution to the Extent of Self-Immolative Chirality Transfer during Reaction Cascades Originating from Squarate Esters

  摘要：

  Reaction cascades induced by the addition to diisopropyl squarate of at least one cycloalkenyl anion possessing an oxygenated leaving group have been examined for the purpose of evaluating the level of chirality transferred to several new stereogenic centers as the original one is destroyed through beta-elimination. A methoxy group alone necessarily resides too far from the bonding sites involved in conrotatory ring closure of the coiled octatetraene intermediate to have a large impact, viz, greater than 22% ee. The situation is considerably improved if a (tert-butyldimethylsilyl)oxy (OTBS) substituent is positioned nearer to this key helical biasing site. The relative rates of ring closure from the two helices of different pitch now become sufficiently different (>100:1) that mechanistic control by OTBS dominates completely, Finally, an example of overwhelming steric bias is detailed (see 30), showing that electrocyclic control can also be achieved in this manner.

  DOI：

  10.1021/jo962182e

文献信息

• Enhanced Channeling of the Squarate Cascade through the Dianionic Oxy-Cope Option. Oxy Substitution Markedly Augments Syn Delivery of the Second Alkenyllithium
  作者：Leo A. Paquette、Lung Huang Kuo、Julien Doyon

  DOI：10.1021/ja964140d

  日期：1997.4.1

  A general means for enhancing the extent to which squarate esters enter into cascade processes involving a dianionic oxy-Cope rearrangement as the key step is presented. Adoption of this sigmatropic process requires that the two alkenyllithium reagents being introduced add cis to each other, a kinetic bias which can be realized simply by the proper incorporation of ethereal oxygen substituents in the first organometallic reagent. Structural reorganization occurs via boat-like transition states such that stereoinduction manifests itself with high fidelity.
• Sensitivity of Substitution to the Extent of Self-Immolative Chirality Transfer during Reaction Cascades Originating from Squarate Esters
  作者：Leo A. Paquette、Lung Huang Kuo、Ashton T. Hamme、Rüdiger Kreuzholz、Julien Doyon

  DOI：10.1021/jo962182e

  日期：1997.3.1

  Reaction cascades induced by the addition to diisopropyl squarate of at least one cycloalkenyl anion possessing an oxygenated leaving group have been examined for the purpose of evaluating the level of chirality transferred to several new stereogenic centers as the original one is destroyed through beta-elimination. A methoxy group alone necessarily resides too far from the bonding sites involved in conrotatory ring closure of the coiled octatetraene intermediate to have a large impact, viz, greater than 22% ee. The situation is considerably improved if a (tert-butyldimethylsilyl)oxy (OTBS) substituent is positioned nearer to this key helical biasing site. The relative rates of ring closure from the two helices of different pitch now become sufficiently different (>100:1) that mechanistic control by OTBS dominates completely, Finally, an example of overwhelming steric bias is detailed (see 30), showing that electrocyclic control can also be achieved in this manner.