2-Bromo-propionic acid phenethyl ester | 43216-34-8

• 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: 2-Bromo-propionic acid phenethyl ester
• 英文别名: Phenethyl 2-bromopropanoate；2-phenylethyl 2-bromopropanoate
• CAS: 43216-34-8
• 化学式: C₁₁H₁₃BrO₂
• 分子量: 257.127
• InChiKey: HDTKBTHJTMZYGF-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.5
• 重原子数：
  14
• 可旋转键数：
  5
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.36
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  2-Bromo-propionic acid phenethyl ester 在 异丙醇 、 反式-二叔丁基连二次硝酸酯 作用下， 反应 5.0h， 生成 丙酸-2-苯乙酯
  参考文献：
  名称：

  Organic Reducing Agents: Some Radical Chain Reactions of Ketyl and 1,3-Dioxolanyl Radicals with Activated Bromides

  摘要：

  The radical chain reduction of primary and secondary alpha-bromo esters by 2-propanol and 2-methyldioxolane has been shown to be a kinetically viable process with average chain lengths of >10 at temperatures between 30 and 60 degrees C. For electron-deficient bromides, these simple organic reagents may effectively replace the more commonly used (and more expensive) organosilicon or tin hydides. Some mechanistic insights have been obtained from a combination of kinetic and thermodynamic measurements. The rate constants for the reaction of the 2-hydroxy-2-propyl and the 2-methyl-1,3-dioxolan-2-yl radicals with a primary bromo ester have been estimated to be 8 x 10(3) M(-1) s(-1) and 6 x 10(3) M(-1) s(-1), respectively, at 30 degrees C in acetonitrile. The electrochemical oxidation potentials of a number of electron-rich radicals derived from hydrogen atom abstraction from alcohols and dioxolanes, determined using photomodulation voltammetry, provide an assessment of the thermochemisty of the putative outer sphere electron-transfer reaction between the radical and the alpha-bromo ester (the value for 1,3-dioxolane has been redetermined and corrects an erroneous value previously published). From these data, it is shown that the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals. Rate constants for the outer sphere electron-transfer reduction of the bromo esters by electrochemically generated radical anions were used to establish a Marcus-type relationship between the rate constants and the standard potential of the reducing agent. Comparison of these rate constants with those for the reactions of the electron-rich radicals suggest that the reactions of the methanol; and ethanol-derived radicals do not proceed via outer sphere electron transfer as had been previously suggested but have significant bonding (i.e., atom transfer) character at the transition state. Electron transfer in the reactions of the 2-propanol- and 2-methyl-1,3-dioxolane-derived radicals cannot be ruled out. Nevertheless, the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals suggesting that these potentials can be used as a predictive tool for the design of new reagents.

  DOI：

  10.1021/jo00095a050
• 作为产物：
  描述：

  苯乙醇 、 2-溴丙酰溴 以 苯 为溶剂， 反应 3.0h， 生成 2-Bromo-propionic acid phenethyl ester
  参考文献：
  名称：

  Organic Reducing Agents: Some Radical Chain Reactions of Ketyl and 1,3-Dioxolanyl Radicals with Activated Bromides

  摘要：

  The radical chain reduction of primary and secondary alpha-bromo esters by 2-propanol and 2-methyldioxolane has been shown to be a kinetically viable process with average chain lengths of >10 at temperatures between 30 and 60 degrees C. For electron-deficient bromides, these simple organic reagents may effectively replace the more commonly used (and more expensive) organosilicon or tin hydides. Some mechanistic insights have been obtained from a combination of kinetic and thermodynamic measurements. The rate constants for the reaction of the 2-hydroxy-2-propyl and the 2-methyl-1,3-dioxolan-2-yl radicals with a primary bromo ester have been estimated to be 8 x 10(3) M(-1) s(-1) and 6 x 10(3) M(-1) s(-1), respectively, at 30 degrees C in acetonitrile. The electrochemical oxidation potentials of a number of electron-rich radicals derived from hydrogen atom abstraction from alcohols and dioxolanes, determined using photomodulation voltammetry, provide an assessment of the thermochemisty of the putative outer sphere electron-transfer reaction between the radical and the alpha-bromo ester (the value for 1,3-dioxolane has been redetermined and corrects an erroneous value previously published). From these data, it is shown that the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals. Rate constants for the outer sphere electron-transfer reduction of the bromo esters by electrochemically generated radical anions were used to establish a Marcus-type relationship between the rate constants and the standard potential of the reducing agent. Comparison of these rate constants with those for the reactions of the electron-rich radicals suggest that the reactions of the methanol; and ethanol-derived radicals do not proceed via outer sphere electron transfer as had been previously suggested but have significant bonding (i.e., atom transfer) character at the transition state. Electron transfer in the reactions of the 2-propanol- and 2-methyl-1,3-dioxolane-derived radicals cannot be ruled out. Nevertheless, the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals suggesting that these potentials can be used as a predictive tool for the design of new reagents.

  DOI：

  10.1021/jo00095a050

文献信息

• Organic reducing agents. Reduction of electron deficient bromides by 1,2,2,6,6-pentamethylpiperidine (PMP)/mercaptoethanol
  作者：Maryam Amoli、Mark S. Workentin、Danial D.M. Wayner

  DOI：10.1016/0040-4039(95)00697-b

  日期：1995.6

  1,2,2,6,6-pentamethylpiperidine (PMP) is shown to be an effective reducing agent for the radical chain conversion of primary bromoesters to the corresponding esters. The problem of inefficient reduction of tertiary bromoesters in these reactions has been overcome by the addition of an alkyl thiol which mediates the hydrogen atom transfer between the two hindered alkyl centers.
• Organic Reducing Agents: Some Radical Chain Reactions of Ketyl and 1,3-Dioxolanyl Radicals with Activated Bromides
  作者：Francesca Fontana、Ralph J. Kolt、Youqin Huang、Danial D. M. Wayner

  DOI：10.1021/jo00095a050

  日期：1994.8

  The radical chain reduction of primary and secondary alpha-bromo esters by 2-propanol and 2-methyldioxolane has been shown to be a kinetically viable process with average chain lengths of >10 at temperatures between 30 and 60 degrees C. For electron-deficient bromides, these simple organic reagents may effectively replace the more commonly used (and more expensive) organosilicon or tin hydides. Some mechanistic insights have been obtained from a combination of kinetic and thermodynamic measurements. The rate constants for the reaction of the 2-hydroxy-2-propyl and the 2-methyl-1,3-dioxolan-2-yl radicals with a primary bromo ester have been estimated to be 8 x 10(3) M(-1) s(-1) and 6 x 10(3) M(-1) s(-1), respectively, at 30 degrees C in acetonitrile. The electrochemical oxidation potentials of a number of electron-rich radicals derived from hydrogen atom abstraction from alcohols and dioxolanes, determined using photomodulation voltammetry, provide an assessment of the thermochemisty of the putative outer sphere electron-transfer reaction between the radical and the alpha-bromo ester (the value for 1,3-dioxolane has been redetermined and corrects an erroneous value previously published). From these data, it is shown that the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals. Rate constants for the outer sphere electron-transfer reduction of the bromo esters by electrochemically generated radical anions were used to establish a Marcus-type relationship between the rate constants and the standard potential of the reducing agent. Comparison of these rate constants with those for the reactions of the electron-rich radicals suggest that the reactions of the methanol; and ethanol-derived radicals do not proceed via outer sphere electron transfer as had been previously suggested but have significant bonding (i.e., atom transfer) character at the transition state. Electron transfer in the reactions of the 2-propanol- and 2-methyl-1,3-dioxolane-derived radicals cannot be ruled out. Nevertheless, the order of reactivity of the organic reducing agents follows the same trend as the oxidation potentials of the corresponding radicals suggesting that these potentials can be used as a predictive tool for the design of new reagents.