trans-PdBr(Mes)(CN-2,6-(2,6-(i-Pr)2C6H3)2C6H3)2 | 1182649-29-1

• 英文名称: trans-PdBr(Mes)(CN-2,6-(2,6-(i-Pr)2C6H3)2C6H3)2
• 英文别名: trans-PdBr(Mes)(CN-2,6-(2,6-(i-Pr)₂C₆H₃)₂C₆H₃)₂；PdBr(mesityl)[2,6-(2,6-(i-Pr)2C6H3)2)phenylisocyanide]
• CAS: 1182649-29-1
• 化学式: C₇₁H₈₅BrN₂Pd
• 分子量: 1152.79
• InChiKey: VDKQKBGAMWCSEL-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为产物：
  描述：

  PdCl2[2,6-(2,6-(i-Pr)2C6H3)2)phenylisocyanide] 在 Mg⁽⁰⁾ 作用下， 以 四氢呋喃 、 乙醚 为溶剂， 生成 trans-PdBr(Mes)(CN-2,6-(2,6-(i-Pr)2C6H3)2C6H3)2
  参考文献：
  名称：

  可分离的双配位 Pd(0) 双异氰化物单体的键活化、底物添加和催化

  摘要：

  二价前体 PdCl(2)(CNAr(Dipp2))(2)（Dipp = 2,6-二异丙基苯基）的镁金属还原提供了可分离的双配位 Pd(0) 双异氰化物 Pd(CNAr(Dipp2) )(2)，这是第一个稳定的零价钯单体异氰化物配合物。在添加 CNAr(Dipp2) 的情况下，对 Pd(CNAr(Dipp2))(2) 的变温 (1)H NMR 和 FTIR 研究表明，游离的和配位的异氰化物会发生快速交换，但组分不会形成稳定的三异氰化物络合物。双异氰化物 Pd(CNAr(Dipp2))(2) 对氧化加成反应很活跃，很容易与苄基氯和甲基溴反应形成 Pd(Cl)(Bz)(CNAr(Dipp2))(2) 和 Pd(Br )(Mes)(CNAr(Dipp2))(2)。室温 Suzuki-Miyaura 交叉偶联反应由 Pd(CNAr(Dipp2))(2) 介导。配位和电子不饱和底物也会与 Pd(CNAr(Dipp2))(2)

  DOI：

  10.1021/ja905338x

文献信息

• Synthetic and Mechanistic Interrogation of Pd/Isocyanide-Catalyzed Cross-Coupling: π-Acidic Ligands Enable Self-Aggregating Monoligated Pd(0) Intermediates
  作者：Brandon R. Barnett、Liezel A. Labios、Julia M. Stauber、Curtis E. Moore、Arnold L. Rheingold、Joshua S. Figueroa

  DOI：10.1021/acs.organomet.7b00035

  日期：2017.2.27

  Despite the large number of judiciously designed ligands that have been exploited in palladium-catalyzed cross-coupling protocols, the incorporation of ligands bearing appreciable pi-acidic properties has remained significantly underexplored. Herein, we demonstrate that well-defined and low-coordinate Pd-0 complexes supported by m-terphenyl isocyanides function as competent catalysts for the Suzuki Miyaura cross-coupling of aryl bromides and arylboronic acids. Two-coordinate Pd(CNArDiPP2)(2) was active for the coupling of unhindered aryl bromides at room temperature in 2-propanol, while increasing the temperature to 60 degrees C allowed for the use of mono-or di-ortho-substituted aryl bromides. Oxidative addition of the aryl bromide was shown to proceed via a dissociative mechanism, implicating monoligated Pd(CNArDipp2) as the catalytically active intermediate. Attempts to access this fleeting species via activation of the Pd-II monoisocyanide PdCl(eta(3)-C3H5)(CNArDipp2) with alkoxide base yielded the dinuclear Pd-I species mu-C3H5(mu-O'Pr)[Pd(CNArDipp2)](2). Although dinuclear Pd-I complexes are often produced as off-cycle species when using complexes of the type PdCl(eta(3)-allyl)L as precatalysts, this represents the first time that the comproportionation product (mu-allyl)(mu-Cl)[PdL](2) has been observed to undergo nucleophilic substitution with alkoxide, despite the fact that activating conditions for these precatalysts typically employ alkoxide bases. Remarkably, this alkoxide complex can undergo, beta-hydride elimination with expulsion of acetone and propene to produce two equivalents of, catalytically active Pd(CNArDipp2), which can self-aggregate to yield the isolable tripalladium cluster Pd-3(eta(2)-Dipp-mu-CNArDipp2)(3). This cluster is catalytically competent for the Suzuki Miyaura reaction and functions as a formal source of monoligated Pd(CNArDipp2) in solution.