4-bromo-2-(p-fluorophenyl)pyridine | 916824-57-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡啶及其衍生物
• 英文名称: 4-bromo-2-(p-fluorophenyl)pyridine
• 英文别名: 4-bromo-2-(4-fluorophenyl)pyridine；4-Bromo-2-(4-fluorophenyl)pyridine
• CAS: 916824-57-2
• 化学式: C₁₁H₇BrFN
• 分子量: 252.086
• InChiKey: WJFDGYZUBKOQNY-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.3
• 重原子数：
  14
• 可旋转键数：
  1
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  12.9
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  2,4-二溴吡啶 、 4-氟苯硼酸 在 四(三苯基膦)钯 氢氧化铊(Ⅰ) 作用下， 以 四氢呋喃 、 水 为溶剂， 反应 16.0h， 以68%的产率得到4-bromo-2-(p-fluorophenyl)pyridine
  参考文献：
  名称：

  Regioselectivity in alkenyl(aryl)-heteroaryl Suzuki cross-coupling reactions of 2,4-dibromopyridine. A synthetic and mechanistic study

  摘要：

  2,4-Dibromopyridine undergoes a regioselective Suzuki cross-coupling reaction at position 2 with several alkenyl(aryl) boronic acids to render 4-bromo-2-carbon substituted pyridines, difficult to be prepared otherwise, in good yields under palladium catalysis, either Pd(PPh3)(4)/TlOH or Pd(2)dba(3)/PCy3/K3PO4 at 25 degrees C. This behavior is explained on the basis of the electrophilic character of both C-Br bonds, being their relative reactivity in 2,4-dibromopyridine similar to that in the corresponding monobromopyridines. In addition, the dicoupled compound 6 is not formed through a double oxidative addition of 2,4-dibromopyri dine to Pd(PPh3). (c) 2006 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2006.09.040

文献信息

• A Dichotomy in Cross-Coupling Site Selectivity in a Dihalogenated Heteroarene: Influence of Mononuclear Pd, Pd Clusters, and Pd Nanoparticles—the Case for Exploiting Pd Catalyst Speciation
  作者：Neil W. J. Scott、Mark J. Ford、Neda Jeddi、Anthony Eyles、Lauriane Simon、Adrian C. Whitwood、Theo Tanner、Charlotte E. Willans、Ian J. S. Fairlamb

  DOI：10.1021/jacs.1c05294

  日期：2021.6.30

  Given that Pd speciation, particularly aggregation, is known to lead to the formation of catalytically competent multinuclear Pdn species, the influence of these species on cross-coupling site-selectivity remains largely unknown. Herein, we disclose that multinuclear Pd species, in the form of Pd3-type clusters and nanoparticles, switch arylation site-selectivity from C2 to C4, in 2,4-dibromopyridine cross-couplings

  与有机金属试剂的位点选择性二卤杂芳烃交叉偶联通常发生在接近杂原子的卤素处，这是由内在的相对亲电性实现的，特别是在强极化体系中。一个典型的例子是 2,4-二溴吡啶与有机硼物质的 Suzuki-Miyaura 交叉偶联 (SMCC)，通常使用单核 Pd（前）催化剂表现出 C2-芳基化位点选择性。鉴于已知 Pd 形态（特别是聚集）会导致具有催化能力的多核 Pd n物种的形成，因此这些物种对交叉偶联位点选择性的影响仍然很大程度上未知。在此，我们公开了Pd 3型簇和纳米颗粒形式的多核Pd物种，在与有机硼酸（SMCC反应）和格氏试剂的2,4-二溴吡啶交叉偶联中将芳基化位点选择性从C2切换到C4试剂（熊田型反应）。发现 Pd/配体比率和合适的稳定盐的存在对于切换位点选择性至关重要。更一般地说，这项研究提供了实验证据，表明聚集的钯催化剂物种不仅具有催化能力，而且还可以通过产物选择性的变化来改变反应结果。
• Regioselectivity in alkenyl(aryl)-heteroaryl Suzuki cross-coupling reactions of 2,4-dibromopyridine. A synthetic and mechanistic study
  作者：Cristina Sicre、J.-Lorenzo Alonso-Gómez、M. Magdalena Cid

  DOI：10.1016/j.tet.2006.09.040

  日期：2006.11

  2,4-Dibromopyridine undergoes a regioselective Suzuki cross-coupling reaction at position 2 with several alkenyl(aryl) boronic acids to render 4-bromo-2-carbon substituted pyridines, difficult to be prepared otherwise, in good yields under palladium catalysis, either Pd(PPh3)(4)/TlOH or Pd(2)dba(3)/PCy3/K3PO4 at 25 degrees C. This behavior is explained on the basis of the electrophilic character of both C-Br bonds, being their relative reactivity in 2,4-dibromopyridine similar to that in the corresponding monobromopyridines. In addition, the dicoupled compound 6 is not formed through a double oxidative addition of 2,4-dibromopyri dine to Pd(PPh3). (c) 2006 Elsevier Ltd. All rights reserved.