2-(4,5-diethyl-1H-imidazol-2-yl)-4-nitrophenol | 1604034-47-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: 2-(4,5-diethyl-1H-imidazol-2-yl)-4-nitrophenol
• CAS: 1604034-47-0
• 化学式: C₁₃H₁₅N₃O₃
• 分子量: 261.28
• InChiKey: XBLQMHHQEGGTLW-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  19
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.31
• 拓扑面积：
  94.7
• 氢给体数：
  2
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  3,4-己二酮 、 5-硝基水杨醛 在 ammonium acetate 、 溶剂黄146 作用下， 反应 1.5h， 以43%的产率得到2-(4,5-diethyl-1H-imidazol-2-yl)-4-nitrophenol
  参考文献：
  名称：

  Ligand characteristics and in situ generation of Pd active species towards CC coupling using series of 2-(1H-imidazol-2-yl)phenols

  摘要：

  Series of systematically varied 2-(1H-imidazol-2-yl)phenol ligand frameworks, which were synthesized and properly characterized, have been used to investigate favourable ligand characteristics towards in situ formation of active palladium species in Suzuki-Miyaura coupling. Structures of 2-(4,5-diethy1-1Himidazol-2-y1)-4-nitrophenol (p-N similar to de) and 4-(tert-butyl)-2-(4,5-dipheny1-1H-imidazol-2-yl)phenol (p-tBu similar to dp) as well as the palladium complex of 2-(4,5-diethyl-1H-imidazol-2-y1)phenol (Pd.de(2)) were confirmed. Structural analyses show that para-nitro-substituted phenol moieties bear poor oxo-donor atom while the reverse was observed for para-dlu-substituted analogues. Ligand donor strengths were also determined by pK(a) analysis.Under the same reaction conditions for palladium catalyzed Suzuki-Miyaura coupling in the presence of 'ligand + palladium( II) acetate' catalyst system, results show that electronic properties of the ligands are more important than the variation in steric properties. In particular, ligands with strong bidentate chelate coordination potentials acted as poisons while those with monodentate coordination potential proved to be very beneficial towards in situ generation of superior active species. Furthermore, correlation between donor strength pKa data and the trends in catalytic efficiencies as a consequence of ligand presence was studied. Therefore, it was concluded that ligands with strong chelation tendencies adversely impacted in situ palladium catalyst generation efficiency and that there appears to be moderate steric requirement from ligands for optimal catalyst efficiency. (C) 2014 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/j.molcata.2014.02.032
• 作为试剂：
  描述：

  4-溴苄醇 、 4-乙酰基苯硼酸 在 2-(4,5-diethyl-1H-imidazol-2-yl)-4-nitrophenol 、 palladium diacetate 作用下， 以 水 、 N,N-二甲基甲酰胺 为溶剂， 反应 1.0h， 以90%的产率得到1-(4'-(hydroxymethyl)biphenyl-4-yl)ethanone
  参考文献：
  名称：

  Ligand characteristics and in situ generation of Pd active species towards CC coupling using series of 2-(1H-imidazol-2-yl)phenols

  摘要：

  Series of systematically varied 2-(1H-imidazol-2-yl)phenol ligand frameworks, which were synthesized and properly characterized, have been used to investigate favourable ligand characteristics towards in situ formation of active palladium species in Suzuki-Miyaura coupling. Structures of 2-(4,5-diethy1-1Himidazol-2-y1)-4-nitrophenol (p-N similar to de) and 4-(tert-butyl)-2-(4,5-dipheny1-1H-imidazol-2-yl)phenol (p-tBu similar to dp) as well as the palladium complex of 2-(4,5-diethyl-1H-imidazol-2-y1)phenol (Pd.de(2)) were confirmed. Structural analyses show that para-nitro-substituted phenol moieties bear poor oxo-donor atom while the reverse was observed for para-dlu-substituted analogues. Ligand donor strengths were also determined by pK(a) analysis.Under the same reaction conditions for palladium catalyzed Suzuki-Miyaura coupling in the presence of 'ligand + palladium( II) acetate' catalyst system, results show that electronic properties of the ligands are more important than the variation in steric properties. In particular, ligands with strong bidentate chelate coordination potentials acted as poisons while those with monodentate coordination potential proved to be very beneficial towards in situ generation of superior active species. Furthermore, correlation between donor strength pKa data and the trends in catalytic efficiencies as a consequence of ligand presence was studied. Therefore, it was concluded that ligands with strong chelation tendencies adversely impacted in situ palladium catalyst generation efficiency and that there appears to be moderate steric requirement from ligands for optimal catalyst efficiency. (C) 2014 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/j.molcata.2014.02.032