4-Chloro-2,6-dimethoxy-5-trimethylsilanylethynyl-pyrimidine | 216979-85-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二嗪类
• 英文名称: 4-Chloro-2,6-dimethoxy-5-trimethylsilanylethynyl-pyrimidine
• 英文别名: 4-Chloro-2,6-dimethoxy-5-[(trimethylsilyl)ethynyl]pyrimidine；2-(4-chloro-2,6-dimethoxypyrimidin-5-yl)ethynyl-trimethylsilane
• CAS: 216979-85-0
• 化学式: C₁₁H₁₅ClN₂O₂Si
• 分子量: 270.791
• InChiKey: HDNAWCWYQABPCL-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.38
• 重原子数：
  17
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  44.2
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  4-Chloro-2,6-dimethoxy-5-trimethylsilanylethynyl-pyrimidine 在 氢氟酸 、 sodium fluoride 作用下， 以 乙醇 、 水 为溶剂， 以78%的产率得到6-chloro-5-ethynyl-2,4-dimethoxypyrimidine
  参考文献：
  名称：

  Rapid Bergman Cyclization of 1,2-Diethynylheteroarenes

  摘要：

  The synthesis and cyclization of acyclic quinoxaline, pyridine, and pyrimidine enediynes (1-3) are described. These compounds were prepared using palladium(0) coupling of trimethylsilyl acetylene to o-dihalo- or o-halotriflic heteroarenes. All compounds were prepared in modest to good yields. The enediynes prepared were shown to undergo Bergman cyclization. Kinetics over a minimum of 3 half-lives were used to construct Arrhenius plots. Pyrimidine 3 was found to have an activation energy of 16.1 kcal/mol. Cyclization of the closest known aromatic analogue, o-diethynylbenzene (15), has E-a = 25.1 kcal/mol (Grissom, J. W.; Calkins, T. L.;McMillen, H. A.; Jiang, Y. J. Org. Chem. 1994, 59, 5833-5835). Pyridine 2 and quinoxaline 1 gave activation energies of 21.5 and 33.6 kcal/mol, respectively. The results illustrate that heteroarenes can be used to activate Bergman cyclization. We expect these compounds to play an important role in furthering the understanding of Bergman cyclization and in aiding the development of new biologically significant enediynes.

  DOI：

  10.1021/jo980879p
• 作为产物：
  描述：

  6-氯-2,4-甲氧基嘧啶 在 四(三苯基膦)钯 N-碘代丁二酰亚胺 、 二异丙胺 、 三氟乙酸酐 作用下， 以 三氟乙酸 为溶剂， 反应 5.3h， 生成 4-Chloro-2,6-dimethoxy-5-trimethylsilanylethynyl-pyrimidine
  参考文献：
  名称：

  Rapid Bergman Cyclization of 1,2-Diethynylheteroarenes

  摘要：

  The synthesis and cyclization of acyclic quinoxaline, pyridine, and pyrimidine enediynes (1-3) are described. These compounds were prepared using palladium(0) coupling of trimethylsilyl acetylene to o-dihalo- or o-halotriflic heteroarenes. All compounds were prepared in modest to good yields. The enediynes prepared were shown to undergo Bergman cyclization. Kinetics over a minimum of 3 half-lives were used to construct Arrhenius plots. Pyrimidine 3 was found to have an activation energy of 16.1 kcal/mol. Cyclization of the closest known aromatic analogue, o-diethynylbenzene (15), has E-a = 25.1 kcal/mol (Grissom, J. W.; Calkins, T. L.;McMillen, H. A.; Jiang, Y. J. Org. Chem. 1994, 59, 5833-5835). Pyridine 2 and quinoxaline 1 gave activation energies of 21.5 and 33.6 kcal/mol, respectively. The results illustrate that heteroarenes can be used to activate Bergman cyclization. We expect these compounds to play an important role in furthering the understanding of Bergman cyclization and in aiding the development of new biologically significant enediynes.

  DOI：

  10.1021/jo980879p

文献信息

• Rapid Bergman Cyclization of 1,2-Diethynylheteroarenes
  作者：Chang-Sik Kim、K. C. Russell

  DOI：10.1021/jo980879p

  日期：1998.11.1

  The synthesis and cyclization of acyclic quinoxaline, pyridine, and pyrimidine enediynes (1-3) are described. These compounds were prepared using palladium(0) coupling of trimethylsilyl acetylene to o-dihalo- or o-halotriflic heteroarenes. All compounds were prepared in modest to good yields. The enediynes prepared were shown to undergo Bergman cyclization. Kinetics over a minimum of 3 half-lives were used to construct Arrhenius plots. Pyrimidine 3 was found to have an activation energy of 16.1 kcal/mol. Cyclization of the closest known aromatic analogue, o-diethynylbenzene (15), has E-a = 25.1 kcal/mol (Grissom, J. W.; Calkins, T. L.;McMillen, H. A.; Jiang, Y. J. Org. Chem. 1994, 59, 5833-5835). Pyridine 2 and quinoxaline 1 gave activation energies of 21.5 and 33.6 kcal/mol, respectively. The results illustrate that heteroarenes can be used to activate Bergman cyclization. We expect these compounds to play an important role in furthering the understanding of Bergman cyclization and in aiding the development of new biologically significant enediynes.