1-acetoxy-2,2,5,6-tetramethylindan | 136708-07-1

• 分子结构分类: 有机化合物 - 苯类化合物 - 茚满类
• 英文名称: 1-acetoxy-2,2,5,6-tetramethylindan
• 英文别名: (2,2,5,6-tetramethyl-1,3-dihydroinden-1-yl) acetate
• CAS: 136708-07-1
• 化学式: C₁₅H₂₀O₂
• 分子量: 232.323
• InChiKey: WYADRBKUQKYWKI-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.49
• 重原子数：
  17.0
• 可旋转键数：
  1.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.53
• 拓扑面积：
  26.3
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  2,2,5,6-tetramethylindan-1,3-dione 在 盐酸 、 air 、 amalgamated zinc 、 10% palladium on active carbon 、 tetrabutylammonium tetrafluoroborate 作用下， 以 乙腈 为溶剂， 反应 1.0h， 生成 1-acetoxy-2,2,5,6-tetramethylindan
  参考文献：
  名称：

  Anodic oxidation of .alpha.-substituted p-xylenes. Electronic and stereoelectronic effects of .alpha.-substituents in the deprotonation of alkylaromatic radical cations

  摘要：

  The effect of alpha-substituents on the deprotonation rate from the benzylic position of alkylaromatic radical cations, k(CH2Z)/k(CH3), has been investigated by determining the intramolecular selectivity in the anodic oxidation in acetic acid of alpha-Z-substituted p-xylenes 1 (Z = H, OMe, OH, Me, tert-butyl, OAc, COOMe, CN), 5,6-dimethylindan 4 (R = H), and 2,2,5,6-tetramethylindan 4 (R = Me). Some oxidations induced by CAN have also been carried out. It has been found that, with the exception of when Z = tert-butyl, the deprotonation rate of I.+ is always faster from the CH2Z group than from the CH3 group, independently of the electron-donating or electron-withdrawing nature of Z. The electron-donating groups (OH, OMe, Me), however, exert a larger effect than the electron-withdrawing ones (COOMe, CN). The negligible deprotonation rate from CH2-t-Bu has been ascribed to stereoelectronic effects (the bulky tert-butyl group does not allow the C-H bonds to be collinear with the pi-system), the suggestion being nicely confirmed by the observation that the deprotonation rate from the position 1(3), relative to that from the 5(6)-methyl group, is almost identical in the radical cations of 4 (R = H and Me). The effect of the other alpha-substituents is mainly of electronic nature and has been rationalized on the basis of a variable transition-state structure for the deprotonation process. It is suggested that with +R groups most of the charge, in the transition state, has been transferred to the C(alpha)-H bond where it can be stabilized by the alpha-substituent. With electron-withdrawing groups less charge transfer has taken place and the rate-enhancing effects of these groups is ascribed to their capability to significantly decrease the strength of the C(alpha)-H bond.

  DOI：

  10.1021/jo00025a036

文献信息

• Anodic oxidation of .alpha.-substituted p-xylenes. Electronic and stereoelectronic effects of .alpha.-substituents in the deprotonation of alkylaromatic radical cations
  作者：Enrico Baciocchi、Mario Mattioli、Roberta Romano、Renzo Ruzziconi

  DOI：10.1021/jo00025a036

  日期：1991.12

  The effect of alpha-substituents on the deprotonation rate from the benzylic position of alkylaromatic radical cations, k(CH2Z)/k(CH3), has been investigated by determining the intramolecular selectivity in the anodic oxidation in acetic acid of alpha-Z-substituted p-xylenes 1 (Z = H, OMe, OH, Me, tert-butyl, OAc, COOMe, CN), 5,6-dimethylindan 4 (R = H), and 2,2,5,6-tetramethylindan 4 (R = Me). Some oxidations induced by CAN have also been carried out. It has been found that, with the exception of when Z = tert-butyl, the deprotonation rate of I.+ is always faster from the CH2Z group than from the CH3 group, independently of the electron-donating or electron-withdrawing nature of Z. The electron-donating groups (OH, OMe, Me), however, exert a larger effect than the electron-withdrawing ones (COOMe, CN). The negligible deprotonation rate from CH2-t-Bu has been ascribed to stereoelectronic effects (the bulky tert-butyl group does not allow the C-H bonds to be collinear with the pi-system), the suggestion being nicely confirmed by the observation that the deprotonation rate from the position 1(3), relative to that from the 5(6)-methyl group, is almost identical in the radical cations of 4 (R = H and Me). The effect of the other alpha-substituents is mainly of electronic nature and has been rationalized on the basis of a variable transition-state structure for the deprotonation process. It is suggested that with +R groups most of the charge, in the transition state, has been transferred to the C(alpha)-H bond where it can be stabilized by the alpha-substituent. With electron-withdrawing groups less charge transfer has taken place and the rate-enhancing effects of these groups is ascribed to their capability to significantly decrease the strength of the C(alpha)-H bond.