9-(o-tert-butylphenyl)-9-fluorofluorene | 259186-13-5

• 分子结构分类: 有机化合物 - 苯类化合物 - 芴
• 英文名称: 9-(o-tert-butylphenyl)-9-fluorofluorene
• 英文别名: 9-(2-Tert-butylphenyl)-9-fluorofluorene
• CAS: 259186-13-5
• 化学式: C₂₃H₂₁F
• 分子量: 316.418
• InChiKey: YRYAEZSIILUELH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.6
• 重原子数：
  24
• 可旋转键数：
  2
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.22
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  9-(o-tert-butylphenyl)-9-fluorofluorene 在 silica gel 作用下， 生成 sp-9-(o-tert-butylphenyl)-9-fluorenol
  参考文献：
  名称：

  The First Reported Halogenation of a tert-Butyl Group with HCl or HBr in CHCl₃. Unexpected Differences in the Reactions of HCl, HBr, HI, and HF with sp-9-(o-tert-Butylphenyl)-9-fluorenol

  摘要：

  The reactions of sp-9-(o-tert-butylphenyl)-9-fluorenol (1) with HCl, HBr, HI, and HF, respectively, were found to follow diverse pathways. Most unexpected is the unprecedented monohalogenation of a tert-butyl group, sp-9-[o-(beta-chloro-alpha,alpha-dimethylethyl)phenyl]fluorene (2) being formed quantitatively from 1 treated with HCl-CHCl3 and sp-9-[o-(beta-bromo-alpha,alpha-dimethylethyl)phenyl]fluorene (3) (>90%), along with a very small amount of sp-9-(o-tert-butylphenyl)fluorene (4), being formed from 1 treated with HBr-CHCl3. The absolute structure of 2 was ascertained by X-ray crystal analysis. Likewise, the expected 9-chloro- and 9-bromofluorenes from the usual substitution of OH by halogen in reactions of alcohols with SOCl4 and SOBr2 were not obtained from treatment of 1 with these reagents; the only products were 2 and 3, respectively. These products are formed by nucleophilic attack of halide ion on a tert-butyl methyl group of the 9-cation (1a) with concerted intramolecular displacement of hydride to 9-C+, while 4 results from the slower electron transfer from Br- to 1a to form free radical 1b, which captures an H atom from HBr. The high redox potential of I- and weak HI bond ensures the rapid conversions 1a --> 1b --> 4, making 4 the exclusive product from treatment of 1 with HI-CHCl3. In contrast to the other halides, fluoride is a poor nucleophile in displacement reactions and poor electron-transfer agent. Consequently, strongly electrophilic la reacts with F- to provide sp-9-(o-tert-butylphenyl)-9-fluorofluorene (5) as the only product from the reaction of 1 with pyridine(HF)(x). Dynamic NMR provided strong evidence that the reaction with HI occurs with inversion, the ap rotamer (4a) of 9-(o-tert-butylphenyl)fluorene being formed initially, followed by rotation to the isolated sp rotamer, 4. The largely planar configuration of C-9 of the unsymmetrically hindered cation intermediate 1a, responsible for this inversion and the related inversions, was supported by NMR.

  DOI：

  10.1021/jo9910280
• 作为产物：
  描述：

  sp-9-(o-tert-butylphenyl)-9-fluorenol 在 氟化氢吡啶 作用下， 反应 1.0h， 生成 9-(o-tert-butylphenyl)-9-fluorofluorene
  参考文献：
  名称：

  The First Reported Halogenation of a tert-Butyl Group with HCl or HBr in CHCl₃. Unexpected Differences in the Reactions of HCl, HBr, HI, and HF with sp-9-(o-tert-Butylphenyl)-9-fluorenol

  摘要：

  The reactions of sp-9-(o-tert-butylphenyl)-9-fluorenol (1) with HCl, HBr, HI, and HF, respectively, were found to follow diverse pathways. Most unexpected is the unprecedented monohalogenation of a tert-butyl group, sp-9-[o-(beta-chloro-alpha,alpha-dimethylethyl)phenyl]fluorene (2) being formed quantitatively from 1 treated with HCl-CHCl3 and sp-9-[o-(beta-bromo-alpha,alpha-dimethylethyl)phenyl]fluorene (3) (>90%), along with a very small amount of sp-9-(o-tert-butylphenyl)fluorene (4), being formed from 1 treated with HBr-CHCl3. The absolute structure of 2 was ascertained by X-ray crystal analysis. Likewise, the expected 9-chloro- and 9-bromofluorenes from the usual substitution of OH by halogen in reactions of alcohols with SOCl4 and SOBr2 were not obtained from treatment of 1 with these reagents; the only products were 2 and 3, respectively. These products are formed by nucleophilic attack of halide ion on a tert-butyl methyl group of the 9-cation (1a) with concerted intramolecular displacement of hydride to 9-C+, while 4 results from the slower electron transfer from Br- to 1a to form free radical 1b, which captures an H atom from HBr. The high redox potential of I- and weak HI bond ensures the rapid conversions 1a --> 1b --> 4, making 4 the exclusive product from treatment of 1 with HI-CHCl3. In contrast to the other halides, fluoride is a poor nucleophile in displacement reactions and poor electron-transfer agent. Consequently, strongly electrophilic la reacts with F- to provide sp-9-(o-tert-butylphenyl)-9-fluorofluorene (5) as the only product from the reaction of 1 with pyridine(HF)(x). Dynamic NMR provided strong evidence that the reaction with HI occurs with inversion, the ap rotamer (4a) of 9-(o-tert-butylphenyl)fluorene being formed initially, followed by rotation to the isolated sp rotamer, 4. The largely planar configuration of C-9 of the unsymmetrically hindered cation intermediate 1a, responsible for this inversion and the related inversions, was supported by NMR.

  DOI：

  10.1021/jo9910280

文献信息

• The First Reported Halogenation of a <i>tert-</i>Butyl Group with HCl or HBr in CHCl₃. Unexpected Differences in the Reactions of HCl, HBr, HI, and HF with <i>sp-</i>9-(<i>o</i><i>-tert-</i>Butylphenyl)-9-fluorenol
  作者：Cal Y. Meyers、Yuqing Hou、Hisham G. Lutfi、Howard L. Saft

  DOI：10.1021/jo9910280

  日期：1999.12.1

  The reactions of sp-9-(o-tert-butylphenyl)-9-fluorenol (1) with HCl, HBr, HI, and HF, respectively, were found to follow diverse pathways. Most unexpected is the unprecedented monohalogenation of a tert-butyl group, sp-9-[o-(beta-chloro-alpha,alpha-dimethylethyl)phenyl]fluorene (2) being formed quantitatively from 1 treated with HCl-CHCl3 and sp-9-[o-(beta-bromo-alpha,alpha-dimethylethyl)phenyl]fluorene (3) (>90%), along with a very small amount of sp-9-(o-tert-butylphenyl)fluorene (4), being formed from 1 treated with HBr-CHCl3. The absolute structure of 2 was ascertained by X-ray crystal analysis. Likewise, the expected 9-chloro- and 9-bromofluorenes from the usual substitution of OH by halogen in reactions of alcohols with SOCl4 and SOBr2 were not obtained from treatment of 1 with these reagents; the only products were 2 and 3, respectively. These products are formed by nucleophilic attack of halide ion on a tert-butyl methyl group of the 9-cation (1a) with concerted intramolecular displacement of hydride to 9-C+, while 4 results from the slower electron transfer from Br- to 1a to form free radical 1b, which captures an H atom from HBr. The high redox potential of I- and weak HI bond ensures the rapid conversions 1a --> 1b --> 4, making 4 the exclusive product from treatment of 1 with HI-CHCl3. In contrast to the other halides, fluoride is a poor nucleophile in displacement reactions and poor electron-transfer agent. Consequently, strongly electrophilic la reacts with F- to provide sp-9-(o-tert-butylphenyl)-9-fluorofluorene (5) as the only product from the reaction of 1 with pyridine(HF)(x). Dynamic NMR provided strong evidence that the reaction with HI occurs with inversion, the ap rotamer (4a) of 9-(o-tert-butylphenyl)fluorene being formed initially, followed by rotation to the isolated sp rotamer, 4. The largely planar configuration of C-9 of the unsymmetrically hindered cation intermediate 1a, responsible for this inversion and the related inversions, was supported by NMR.