1,3-dibromohexafluorobicyclo[1.1.1]pentane | 199917-46-9

• 分子结构分类: 有机化合物 - 有机卤素化合物 - 有机氟化物
• 英文名称: 1,3-dibromohexafluorobicyclo[1.1.1]pentane
• 英文别名: 1,3-Dibromo-2,2,4,4,5,5-hexafluorobicyclo[1.1.1]pentane
• CAS: 199917-46-9
• 化学式: C₅Br₂F₆
• 分子量: 333.853
• InChiKey: SOSFVFGOSHFBOR-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.1
• 重原子数：
  13
• 可旋转键数：
  0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  1,3-dibromohexafluorobicyclo[1.1.1]pentane 在 samarium diiodide 作用下， 以 四氢呋喃 为溶剂， 生成 1,3-diiodohexafluorobicyclo[1.1.1]pentane
  参考文献：
  名称：

  Preparation, Structure, and Properties of Symmetrically 1,3-Difunctionalized Penta- and Hexafluorobicyclo[1.1.1]pentanes

  摘要：

  Exhaustive direct fluorination of dimethyl bicyclo[1.1.1]pentane-1,3-dicarboxylate leads to dimethyl pentafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (2) and hexafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (3). The latter was hydrolyzed to the diacid (4) and converted to the 1,3-dibromo and 1,3-diiodo analogues (5 and 6) by the Hunsdieker reaction followed by treatment with SmI2. Na/NH3 reduction of the disodium salt 10 causes cage C-C bond cleavage. Single-crystal X-ray diffraction analysis of 3 revealed very short nonbonded F-F separations of 2.41 Angstrom and an interbridgehead distance of 1.979 Angstrom, long compared with 1.875 Angstrom in 1,3-diacetylbicyclo[1.1.1]pentane [19; cf. 1.954 Angstrom calculated (MP2/6-31G*) for 2,2,4,4,5,5-hexafluorobicyclo[1.1.1]pentane (13)]. Calculation suggests a strain energy of 101 kcal/mol (MP2/6-31G*) for the hexafluorinated cage, compared with 68 kcal/mol for the parent bicyclo[1.1.1]pentane (20). The remarkably low pK(a) values of 4 [0.73 and 1.34; cf. 3.22 and 4.26 for the parent diacid 24] originate in a direct field effect of fluorine atoms, combined with an increased s character of the exocyclic hybrid orbital on the bridgehead carbon in 4 (calculated 34% in 13) relative to 24 (calculated 30% in 20). Analysis of the strongly coupled nuclear spin systems of 2 and 3, based on a combination of two-dimensional NMR, spectral simulations, and GIAO-HF/6-31G* calculations of chemical shifts, revealed large and stereospecific long-range H-1-C-13, H-1-F-19, C-13-F-19, and F-19-F-19 spin-spin coupling constants.

  DOI：

  10.1021/ja9710518
• 作为产物：
  描述：

  1,3-二甲酸甲酯双环[1.1.1]戊烷 在 sodium hydroxide 、 溴 、 magnesium sulfate 、 fluorine 、 mercury(II) oxide 作用下， 以 甲醇 、 1,1,2-三氯三氟乙烷（CFC-113） 为溶剂， 反应 41.0h， 生成 1,3-dibromohexafluorobicyclo[1.1.1]pentane
  参考文献：
  名称：

  Preparation, Structure, and Properties of Symmetrically 1,3-Difunctionalized Penta- and Hexafluorobicyclo[1.1.1]pentanes

  摘要：

  Exhaustive direct fluorination of dimethyl bicyclo[1.1.1]pentane-1,3-dicarboxylate leads to dimethyl pentafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (2) and hexafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (3). The latter was hydrolyzed to the diacid (4) and converted to the 1,3-dibromo and 1,3-diiodo analogues (5 and 6) by the Hunsdieker reaction followed by treatment with SmI2. Na/NH3 reduction of the disodium salt 10 causes cage C-C bond cleavage. Single-crystal X-ray diffraction analysis of 3 revealed very short nonbonded F-F separations of 2.41 Angstrom and an interbridgehead distance of 1.979 Angstrom, long compared with 1.875 Angstrom in 1,3-diacetylbicyclo[1.1.1]pentane [19; cf. 1.954 Angstrom calculated (MP2/6-31G*) for 2,2,4,4,5,5-hexafluorobicyclo[1.1.1]pentane (13)]. Calculation suggests a strain energy of 101 kcal/mol (MP2/6-31G*) for the hexafluorinated cage, compared with 68 kcal/mol for the parent bicyclo[1.1.1]pentane (20). The remarkably low pK(a) values of 4 [0.73 and 1.34; cf. 3.22 and 4.26 for the parent diacid 24] originate in a direct field effect of fluorine atoms, combined with an increased s character of the exocyclic hybrid orbital on the bridgehead carbon in 4 (calculated 34% in 13) relative to 24 (calculated 30% in 20). Analysis of the strongly coupled nuclear spin systems of 2 and 3, based on a combination of two-dimensional NMR, spectral simulations, and GIAO-HF/6-31G* calculations of chemical shifts, revealed large and stereospecific long-range H-1-C-13, H-1-F-19, C-13-F-19, and F-19-F-19 spin-spin coupling constants.

  DOI：

  10.1021/ja9710518

文献信息

• Preparation, Structure, and Properties of Symmetrically 1,3-Difunctionalized Penta- and Hexafluorobicyclo[1.1.1]pentanes
  作者：Michael D. Levin、Steven J. Hamrock、Piotr Kaszynski、Alexander B. Shtarev、Galina A. Levina、Bruce C. Noll、Martin E. Ashley、Richard Newmark、George G. I. Moore、Josef Michl

  DOI：10.1021/ja9710518

  日期：1997.12.1

  Exhaustive direct fluorination of dimethyl bicyclo[1.1.1]pentane-1,3-dicarboxylate leads to dimethyl pentafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (2) and hexafluorobicyclo[1.1.1]pentane-1,3-dicarboxylate (3). The latter was hydrolyzed to the diacid (4) and converted to the 1,3-dibromo and 1,3-diiodo analogues (5 and 6) by the Hunsdieker reaction followed by treatment with SmI2. Na/NH3 reduction of the disodium salt 10 causes cage C-C bond cleavage. Single-crystal X-ray diffraction analysis of 3 revealed very short nonbonded F-F separations of 2.41 Angstrom and an interbridgehead distance of 1.979 Angstrom, long compared with 1.875 Angstrom in 1,3-diacetylbicyclo[1.1.1]pentane [19; cf. 1.954 Angstrom calculated (MP2/6-31G*) for 2,2,4,4,5,5-hexafluorobicyclo[1.1.1]pentane (13)]. Calculation suggests a strain energy of 101 kcal/mol (MP2/6-31G*) for the hexafluorinated cage, compared with 68 kcal/mol for the parent bicyclo[1.1.1]pentane (20). The remarkably low pK(a) values of 4 [0.73 and 1.34; cf. 3.22 and 4.26 for the parent diacid 24] originate in a direct field effect of fluorine atoms, combined with an increased s character of the exocyclic hybrid orbital on the bridgehead carbon in 4 (calculated 34% in 13) relative to 24 (calculated 30% in 20). Analysis of the strongly coupled nuclear spin systems of 2 and 3, based on a combination of two-dimensional NMR, spectral simulations, and GIAO-HF/6-31G* calculations of chemical shifts, revealed large and stereospecific long-range H-1-C-13, H-1-F-19, C-13-F-19, and F-19-F-19 spin-spin coupling constants.