p-Methoxyphenyl-metoxy-carbonium Ion | 878044-11-2

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: p-Methoxyphenyl-metoxy-carbonium Ion
• 英文别名: (4-Methoxyphenyl)methylidene-methyloxidanium
• CAS: 878044-11-2
• 化学式: C₉H₁₁O₂
• 分子量: 151.185
• InChiKey: CIABEJDCNNVPOL-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.7
• 重原子数：
  11
• 可旋转键数：
  2
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.22
• 拓扑面积：
  10.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  p-Methoxyphenyl-metoxy-carbonium Ion 在 叠氮阴离子 作用下， 以 水 为溶剂， 生成 Azidomethoxy(4-methoxyphenyl)methane
  参考文献：
  名称：

  Carbocation lifetimes that are independent of carbocation stability: the reaction of α-substituted 4-methoxybenzyl carbocations

  摘要：

  α-甲氧基-4-甲氧基苄基碳正离子与溶剂三氟乙醇→水（50：50 v/v）反应，速率常数ks= 3 × 107 s→1；当碳正离子通过强吸电子α-CF3 取代基取代强给电子α-OMe 取代基而不稳定时，ks 增加不到两倍。

  DOI：

  10.1039/c39910000200
• 作为产物：
  描述：

  Azidomethoxy(4-methoxyphenyl)methane 以 水 为溶剂， 生成 p-Methoxyphenyl-metoxy-carbonium Ion
  参考文献：
  名称：

  Carbocation lifetimes that are independent of carbocation stability: the reaction of α-substituted 4-methoxybenzyl carbocations

  摘要：

  α-甲氧基-4-甲氧基苄基碳正离子与溶剂三氟乙醇→水（50：50 v/v）反应，速率常数ks= 3 × 107 s→1；当碳正离子通过强吸电子α-CF3 取代基取代强给电子α-OMe 取代基而不稳定时，ks 增加不到两倍。

  DOI：

  10.1039/c39910000200

文献信息

• The effects of .alpha.-substituents on the kinetic and thermodynamic stability of 4-methoxybenzyl carbocations: carbocation lifetimes that are independent of their thermodynamic stability
  作者：Tina L. Amyes、Ishmael W. Stevens、John P. Richard

  DOI：10.1021/jo00074a036

  日期：1993.10

  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
• Mayr, Herbert; Gorath, Gorden, Journal of the American Chemical Society, 1995, vol. 117, # 30, p. 7862 - 7867
  作者：Mayr, Herbert、Gorath, Gorden

  DOI：——

  日期：——