Bis-(pentamethylbenzyl)-durol | 21979-72-6

• 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: Bis-(pentamethylbenzyl)-durol
• 英文别名: 1,2,3,4,5-Pentamethyl-6-[[2,3,5,6-tetramethyl-4-[(2,3,4,5,6-pentamethylphenyl)methyl]phenyl]methyl]benzene
• CAS: 21979-72-6
• 化学式: C₃₄H₄₆
• 分子量: 454.739
• InChiKey: NQJLGUUBPALCME-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  10.9
• 重原子数：
  34
• 可旋转键数：
  4
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.47
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为产物：
  描述：

  1,2,4,5-四甲苯 、 1-acetoxymethyl-2,3,4,5,6-pentamethylbenzene 在 三氟甲磺酸 作用下， 以 二氯甲烷 为溶剂， 反应 0.08h， 以57%的产率得到Bis-(pentamethylbenzyl)-durol
  参考文献：
  名称：

  Transmission of internal rotations: correlated, uncorrelated, and localized disrotatory rotations in propeller chains

  摘要：

  The stereochemistry of the propeller chain systems 5 and 6 is analyzed. These systems possessing two or three partially overlapping diarylmethyl moieties, respectively, exist in several conformations arising from the different possible helicities and chain arrangements. System 5 was prepared by acid-catalyzed reaction of pentamethylbenzyl acetate with durene. The H-1 NMR spectrum of 5 indicates, even at 150 K, that there is a rapid rotation of the rings on the NMR time scale. The relative energies of the conformations and the barriers for the internal rotation of the systems were calculated using molecular mechanics, and the results were compared with the parent system decamethyldiphenylmethane (4). The rotational mechanism of lowest activational energy of 5 and 6 is a localized disrotation in which only two neighboring rings in the chain rotate in unison. This results in a helicity reversal of the two rings and a change in the conformation of the chain. Enantiomerization of any conformation of 6 is achieved by at least three successive localized disrotatory rotations. The calculations show that the longer the propeller chain, the larger the energy barrier for a correlated rotation pathway involving all rings and this results in a smaller energetic preference of the correlated over uncorrelated (180-degrees) rotations. This poses a limitation on the transmission of internal rotation of coupled rotors along a chain. Only systems with tightly meshed rotors and with a large energy gap between correlated and uncorrelated rotations may have efficient transmission of correlated rotations.

  DOI：

  10.1021/jo00076a027