α-(ethoxycarbonyl)-4-methoxybenzyl alcohol pentafluorobenzoate ester | 136878-05-2

• 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: α-(ethoxycarbonyl)-4-methoxybenzyl alcohol pentafluorobenzoate ester
• 英文别名: Ethyl 4-methoxymandelate pentafluorobenzoate；[2-ethoxy-1-(4-methoxyphenyl)-2-oxoethyl] 2,3,4,5,6-pentafluorobenzoate
• CAS: 136878-05-2
• 化学式: C₁₈H₁₃F₅O₅
• 分子量: 404.29
• InChiKey: DPQAPRWDDXGPFZ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.85
• 重原子数：
  28.0
• 可旋转键数：
  6.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.22
• 拓扑面积：
  61.83
• 氢给体数：
  0.0
• 氢受体数：
  5.0

反应信息

• 作为反应物：
  描述：

  α-(ethoxycarbonyl)-4-methoxybenzyl alcohol pentafluorobenzoate ester 在 sodium perchlorate 、 水 、 三氟乙酸 作用下， 生成 [4-(2-Ethoxy-2-oxoethylidene)cyclohexa-2,5-dien-1-ylidene]-methyloxidanium
  参考文献：
  名称：

  Generation and determination of the lifetime of an α-carbonyl substituted carbocation

  摘要：

  The alpha-carboxyethyl-4-methoxybenzyl carbocation reacts with a solvent of 50:50 (v:v) trifluoroethanol/water with a rate constant k(S) = 1.4 x 10(7) s-1, which is 14-fold slower than the capture of the unsubstituted 4-methoxybenzyl carbocation.

  DOI：

  10.1016/s0040-4039(00)92142-7
• 作为产物：
  描述：

  对甲氧基苦杏仁酸 在 4-吡咯烷基吡啶 、 对甲苯磺酸 、 N,N'-二环己基碳二亚胺 作用下， 以 乙醚 为溶剂， 反应 7.0h， 生成 α-(ethoxycarbonyl)-4-methoxybenzyl alcohol pentafluorobenzoate ester
  参考文献：
  名称：

  The effects of .alpha.-substituents on the kinetic and thermodynamic stability of 4-methoxybenzyl carbocations: carbocation lifetimes that are independent of their thermodynamic stability

  摘要：

  The following new rate constants for reaction of alpha-substituted 4-methoxybenzyl carbocations, 4-MeOC6H4CR1(R2)+, With a solvent of 50:50 (v/v) trifluoroethanol/water at 25-degrees-C and ionic strength 0.50 (NaClO4) are reported: 4-MeOC6H4CH(OMe)+, k(S) = 2.2 X 10(7) s-1; 4-MeOC6H4CH(N3)+, k(S) = 3.3 X 10(5) s-1; 4-MeOC6H4C(CH3)2+, k(S) = 1.3 x 10(7) s-1; 4-MeOC6H4CH(CO2Et)+, k(S) = 1.4 X 10(7) s-1; 4-MeOC6H4CCH3(CF3)+, k(S) = 2.5 x 10(7) s-1. The values of k(S) for reaction of 4-MeOC6H4CR1(R2)+ with 50:50 (v/v) trifluoroethanol/water are nearly independent of very large changes in the thermodynamic stability of these carbocations caused by the addition of a wide range of electron-withdrawing or electron-donating groups at the alpha-position. In the most extreme case, the change from an alpha-methoxy to two alpha-(trifluoromethyl) substituents leads to a 23 kcal/mol thermodynamic destabilization of 4-MeOCrH4CR1(R2)+ relative to the neutral azide ion adducts but a 5-fold decrease in its reactivity toward solvent. The data show that the effects of alpha-substituents on the kinetic stability of 4-MeOC6H4CR1(R2)+ are complex and do not parallel the thermodynamic stability of these carbocations. The results are explained by consideration of the polar and resonance effects of the alpha-substituents on both the thermodynamic driving force and the intrinsic barrier for capture of the carbocations by solvent. These reactions are a new example of the consequences of the ''principle of nonperfect synchronization''.41

  DOI：

  10.1021/jo00074a036

文献信息

• How Does Organic Structure Determine Organic Reactivity? Nucleophilic Substitution and Alkene-Forming Elimination Reactions of α-Carbonyl and α-Thiocarbonyl Substituted Benzyl Derivatives
  作者：John P. Richard、Shrong-Shi Lin、Jeanne M. Buccigross、Tina L. Amyes

  DOI：10.1021/ja9629064

  日期：1996.1.1

  The effect of α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents on the rate constants for partitioning of α-substituted 1-(4-methoxyphenyl)ethyl carbocations between nucleophilic addition of 50:50 (v:v) MeOH/H2O (ks, s-1) and deprotonation by this solvent (ke, s-1) have been investigated. The data show that these α-amide and α-thioamide substituents result in 80-fold and ≥30 000-fold

  α-(N,N-二甲基氨基甲酰基)和α-(N,N-二甲基硫代氨基甲酰基)取代基对α-取代的1-(4-甲氧基苯基)乙基碳正离子在50:50亲核加成之间分配速率常数的影响( v:v) MeOH/H2O (ks, s-1) 和该溶剂的去质子化 (ke, s-1) 已被研究。数据显示，这些 α-酰胺和 α-硫代酰胺取代基分别导致溶剂捕获 4-甲氧基苄基碳正离子的 ks 减少 80 倍和≥30 000 倍，但它们导致的变化要小得多。 ke用于通过溶剂使相应的α-取代的1-（4-甲氧基苯基）乙基碳正离子去质子化。因此，α-硫代酰胺取代基对 α-取代的 1-苯乙基碳正离子在溶剂分解和消除产物的形成之间分配的巨大影响主要是由于该 α-取代基对溶剂捕获碳正离子的 ks 的影响. 实验和计算研究的结果与共同...