三叔戊基膦(TNpP)与钯的结合为空间受限的芳族溴化物和氯化物与空间受阻的苯胺衍生物的布赫瓦尔德-哈特维格偶联提供了一种高效的催化剂。即使两个底物都包含2,6-二异丙基取代基,也可获得优异的产率。值得注意的是,反应速率与底物的空间需求成反比。Pd(TNpP)2,[Pd(4- t -Bu-C 6 H 4)(TNpP)(μ-Br)] 2和[Pd(2-Me-C 6 H 4)的X射线晶体结构(TNpP)(μ-Br)] 2被报道。这些结构表明,TNpP配体的构象柔韧性在允许催化剂偶联受阻底物方面起着关键作用。Pd / TNpP系统对受阻芳基溴化物的Suzuki偶联也显示出良好的活性。
Effect of Aryl Ligand Identity on Catalytic Performance of Trineopentylphosphine Arylpalladium Complexes in <i>N</i>-Arylation Reactions
作者:Huaiyuan Hu、Corrie E. Burlas、Sabrina J. Curley、Tomasz Gruchala、Fengrui Qu、Kevin H. Shaughnessy
DOI:10.1021/acs.organomet.0c00140
日期:2020.10.26
A series of air-stable [(Np3P)Pd(Ar)Br]2 (Np = neopentyl) and (Np3P)Pd(Ar)(amine)Br complexes (amine = morpholine and isobutylamine) have been prepared and tested as precatalysts for the coupling of sterically demanding aryl bromides and aniline derivatives. The complexes are more active than the catalyst generated in situ from Pd2(dba)3 and PNp3. Increasing steric demand of the aryl group on palladium
Synthesis, Structural Characterization, and Coordination Chemistry of (Trineopentylphosphine)palladium(aryl)bromide Dimer Complexes ([(Np<sub>3</sub>P)Pd(Ar)Br]<sub>2</sub>)
作者:Huaiyuan Hu、Monica Vasiliu、Trent H. Stein、Fengrui Qu、Deidra L. Gerlach、David A. Dixon、Kevin H. Shaughnessy
DOI:10.1021/acs.inorgchem.9b02164
日期:2019.10.7
equilibria of the [(PNp3)Pd(Ar)Br]2 complexes with pyridinederivatives were determined experimentally and analyzed computationally. The binding equilibria are sensitive to the steric demand of the pyridine ligand and less sensitive to the steric demand of the aryl ligand on palladium. In contrast to previous studies, the binding equilibria do not correlate with pyridine basicity. The binding equilibria
Mechanistic Study of the Role of Substrate Steric Effects and Aniline Inhibition on the Bis(trineopentylphosphine)palladium(0)-Catalyzed Arylation of Aniline Derivatives
作者:Huaiyuan Hu、Fengrui Qu、Deidra L. Gerlach、Kevin H. Shaughnessy
DOI:10.1021/acscatal.7b00024
日期:2017.4.7
The mechanism of the bis(trineopentylphosphine)palladium(0) (Pd(PNp3)2)-catalyzed coupling of aryl halides and aniline derivatives was studied in an effort to understand the role of substrate steric effects on the reaction. Prior studies had shown that the rate of Pd/PNp3-catalyzed coupling of aryl bromides and aniline derivatives was largely unaffected by substrate steric demand. The oxidative addition
Air-Stable [(R<sub>3</sub>P)PdCl<sub>2</sub>]<sub>2</sub>Complexes of Neopentylphosphines as Cross-Coupling Precatalysts: Catalytic Application and Mechanism of Catalyst Activation and Deactivation
作者:Kerry L. Barnett、James R. Howard、Colin J. Treager、Adam T. Shipley、Renee M. Stullich、Fengrui Qu、Deidra L. Gerlach、Kevin H. Shaughnessy
DOI:10.1021/acs.organomet.8b00082
日期:2018.5.14
performed in air. The precatalyst systems provided much higher activity catalysts in toluene/water in comparison to acetonitrile/water. Precatalyst loadings could be decreased by a factor of 50 in toluene in comparison to acetonitrile, while achieving equal or better yields. In acetonitrile/water, ligand metalation to form a [(κ2-P,C-DTBNpP)PdX]2 palladacycle was found to compete with formation of
The(akoxycarbonyl) cobalt tetracarbonylnBuOC(O)(Co(CO)4(Ia) was treated with the ligands ER3 (E = P, As, Sb; R= alkyl, aryl, alkoxy, dialkylamino) to give 37 monosubstituted products (IIa). Disubstituted derivatives (IIIa) containing PR3(R = Et, OMe)ligands were also made from Ia. The IR spectra of compouns IIa containing various PR3 ligands were correlated with the electronic and steric parameters of the P-ligands