1,1,2,2-tetramethylcyclopropane radical | 133753-28-3

• 分子结构分类: 有机化合物
• 英文名称: 1,1,2,2-tetramethylcyclopropane radical
• CAS: 133753-28-3
• 化学式: C₇H₁₃
• 分子量: 97.1802
• InChiKey: FVABXSZJOAOUKG-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.26
• 重原子数：
  7.0
• 可旋转键数：
  0.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.86
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  1,1,2,2-tetramethylcyclopropane radical 在 potassium phosphate buffer 、 乙二胺四乙酸 、 microsomal cytochrome P-450 、 potassium chloride 、 氧气 、 还原型辅酶II(NADPH)四钠盐 作用下， 反应 0.5h， 生成 1,2,2-trimethylcyclopropanemethanol
  参考文献：
  名称：

  A radical clock investigation of microsomal cytochrome P-450 hydroxylation of hydrocarbons. Rate of oxygen rebound

  摘要：

  A number of alkyl-substituted cyclopropanes for which the rates of ring opening of the corresponding cyclopropylcarbinyl radicals have been determined (see preceding paper in this issue) have been used as substrates for hydroxylation by phenobarbital-induced, rat liver microsomal cytochrome P-450 at 37-degrees-C. Three of these compounds gave both ring-closed and ring-opened alcohols, thus allowing the rate constant, k(OH), for ''oxygen rebound'' onto the corresponding carbon-centered radicals to be determined. In particular, both trans- (1bH) and cis- (1cH) 1,2-dimethylcyclopropane gave 4-penten-2-ol (2bOH) and 2-methyl-3-buten-1-ol (3bOH) together with the corresponding trans- (1bOH) or cis-(1cOH) 2-methylcyclopropanemethanols. Of much greater importance, for both 1bH and 1cH the ratios of the yields of the secondary-to-primary ring-opened alcohols, i.e., [2bOH]/[3bOH], were the same, within experimental error as the ratio of the rates of ring opening of the corresponding trans- (1b.) and cis- (1c.) methylcyclopropylmethyl radicals in solution at 37-degrees-C. This indicates that when lb. and lc. are formed from their parent hydrocarbons by H-atom abstraction in the hydrophobic pocket of cytochrome P-450 they are not detectably constrained in their subsequent reactions by their unusual environment. From the ratio of the yields of the unrearranged alcohol to each of the rearranged alcohols we calculate k(OH) values of 1.5 and 1.6 x 10(10) s-1 for lbH as substrate and values of 1.9 and 1.8 x 10(10) s-1 for 1cH as substrate. Consistent with these values we have obtained k(OH) = 2.2 x 10(10) s-1 for bicyclo[2.1.0]pentane as substrate. Substrates such as methylcyclopropane and 1,1-dimethylcyclopropane, for which the corresponding cyclopropylmethyl radicals undergo relatively slow ring opening, yielded only the ring-closed alcohols on oxidation with cytochrome P-450. 1,1,2,2-Tetramethylcyclopropane gave only a trace of a ring-opened alcohol, corresponding to k(OH) = 2.5 x 10(11) s-1 for this substrate. Hexamethylcyclopropane gave no detectable ring-opened alcohol from which observation a limit for k(OH) > 5 X 10(11) s-1 can bc calculated. Possible explanations for the unexpected behavior of these last two, relatively bulky, substrates are discussed.

  DOI：

  10.1021/ja00015a025

文献信息

• Kinetics of nitroxide radical trapping. 2. Structural effects
  作者：V. W. Bowry、K. U. Ingold

  DOI：10.1021/ja00039a006

  日期：1992.6

  Laser flash photolysis and kinetic competition product studies have demonstrated that in isooctane at ambient temperatures the rate constant for coupling of carbon-centered radicals with persistent nitroxides, k T , depends upon the degree of steric hindrance to coupling and upon the extent of resonance stabilization of the carbon radical. Sterically induced reductions in the magnitude of k T are observed

  激光闪光光解和动力学竞争产物研究表明，在环境温度下，在异辛烷中，以碳为中心的自由基与持久性氮氧化合物的偶联速率常数 k T 取决于偶联的空间位阻程度和共振稳定的程度。碳自由基。对于氮氧化合物结构和碳自由基结构的变化，观察到 k T 大小的空间诱导减少。因此，对于任何特定的碳基，k T 对于 Bredt 规则保护的氮氧化物、9-氮杂双环 [3.3.1] 壬烷-N-氧基 (ABNO) 和去甲托烷-N-氧基而言是最大的，而对于通常的'二叔-烷基氮氧化物 k T 沿系列递减，1,1,3,3-四甲基异碘啉-2-氧基≥2,2,5,5-四甲基哌啶-1-氧基（Tempo）>二叔丁基氮氧化物，i．
• Bowry, Vincent W.; Lusztyk, Janusz; Ingold, Journal of the American Chemical Society, 1991, vol. 113, # 15, p. 5687 - 5698
  作者：Bowry, Vincent W.、Lusztyk, Janusz、Ingold

  DOI：——

  日期：——