1-(Benzyloxy)-5-(trimethylsilyl)pyrazole | 166820-36-6

• 分子结构分类: 有机化合物 - 有机金属化合物 - 有机类金属化合物
• 英文名称: 1-(Benzyloxy)-5-(trimethylsilyl)pyrazole
• 英文别名: 1-benzyloxy-5-(trimethylsilyl)pyrazole；Trimethyl-(2-phenylmethoxypyrazol-3-yl)silane
• CAS: 166820-36-6
• 化学式: C₁₃H₁₈N₂OSi
• 分子量: 246.384
• InChiKey: RNJSMYWZZSZENS-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.06
• 重原子数：
  17
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.31
• 拓扑面积：
  27
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  1-(Benzyloxy)-5-(trimethylsilyl)pyrazole 在 palladium on activated charcoal 氢气 作用下， 以 甲醇 为溶剂， 反应 2.0h， 以99%的产率得到1-Hydroxy-5-(trimethylsilyl)pyrazole
  参考文献：
  名称：

  Synthesis of 5-Substituted 1-Hydroxypyrazoles through Directed Lithiation of 1-(Benzyloxy)pyrazole

  摘要：

  1-Hydroxypyrazoles have been converted to 1-(benzyloxy), [(9-phenylfluorenyl)oxy], [(N,N-diethylcarbamoyl)oxy], and (-silyloxy)pyrazoles. 1-(Benzyloxy)pyrazole was lithiated selectively in the 5-position. Subsequent reaction with electrophiles gives rise to 1-(benzyloxy)pyrazole with carbon, halogen, silicon, sulfur, or tin substituents at the 5-position. 1-(Benzyloxy)pyrazoles could be debenzylated by hydrogen bromide or hydrogenolysis producing 5-substituted 1-hydroxypyrazoles in high overall yield.

  DOI：

  10.1021/jo00121a017
• 作为产物：
  描述：

  三甲基氯硅烷 、 1-(苄氧基)吡唑 在 四甲基乙二胺 正丁基锂 作用下， 以 四氢呋喃 、 正己烷 为溶剂， 以87%的产率得到1-(Benzyloxy)-5-(trimethylsilyl)pyrazole
  参考文献：
  名称：

  Synthesis of 5-Substituted 1-Hydroxypyrazoles through Directed Lithiation of 1-(Benzyloxy)pyrazole

  摘要：

  1-Hydroxypyrazoles have been converted to 1-(benzyloxy), [(9-phenylfluorenyl)oxy], [(N,N-diethylcarbamoyl)oxy], and (-silyloxy)pyrazoles. 1-(Benzyloxy)pyrazole was lithiated selectively in the 5-position. Subsequent reaction with electrophiles gives rise to 1-(benzyloxy)pyrazole with carbon, halogen, silicon, sulfur, or tin substituents at the 5-position. 1-(Benzyloxy)pyrazoles could be debenzylated by hydrogen bromide or hydrogenolysis producing 5-substituted 1-hydroxypyrazoles in high overall yield.

  DOI：

  10.1021/jo00121a017

文献信息

• Regioselective Introduction of Electrophiles in the 4-Position of 1-Hydroxypyrazole via Bromine−Lithium Exchange
  作者：Thomas Balle、Per Vedsø、Mikael Begtrup

  DOI：10.1021/jo981970w

  日期：1999.7.1

  Two protocols for introduction of electrophiles at the 4-position of 1-hydroxypyrazoles have been developed. The first is deprotonation of 4-bromo-1-[(tert-butyldiphenylsilyl)oxy]pyrazole (6) with LDA to produce the 5-lithio derivative in which the silyl group migrates spontaneously from oxygen to C-5 affording 4-bromo-5-(tert-butyldiphenylsilyl)-1-lithoxypyrazole (8). Subsequent treatment with t-BuLi causes bromine-lithium exchange to give 5-tert-butyldiphenylsilyl-4-lithio-1-lithoxypyrazole which is trapped with electrophiles affording 4-substituted 5-(tert-butyldiphenylsilyl)-1-hydroxypyrazoles 9a-e in a one-pot sequence. The second is treatment of 4-bromo-1-hydroxypyrazole (5) with excess LDA and trimethylsilyl chloride to produce 3,5-bis(trimethylsilyl)-4-bromo-1-hydropyrazole (12), which upon sequential metalation with n-BuLi and reaction with electrophiles affords 4-substituted 3,5-bis(trimethylsilyl)-1-hydroxypyrazol 13a-e. The tert-butyldiphenylsilyl group of 9a and the trimethylsilyl groups of 12 can be removed selectively by treatment with tetrabutylammonium fluoride in THF in the presence of trifluoroacetic acid.
• Synthesis of 5-Substituted 1-Hydroxypyrazoles through Directed Lithiation of 1-(Benzyloxy)pyrazole
  作者：Per Vedso、Mikael Begtrup

  DOI：10.1021/jo00121a017

  日期：1995.8

  1-Hydroxypyrazoles have been converted to 1-(benzyloxy), [(9-phenylfluorenyl)oxy], [(N,N-diethylcarbamoyl)oxy], and (-silyloxy)pyrazoles. 1-(Benzyloxy)pyrazole was lithiated selectively in the 5-position. Subsequent reaction with electrophiles gives rise to 1-(benzyloxy)pyrazole with carbon, halogen, silicon, sulfur, or tin substituents at the 5-position. 1-(Benzyloxy)pyrazoles could be debenzylated by hydrogen bromide or hydrogenolysis producing 5-substituted 1-hydroxypyrazoles in high overall yield.