Perfluoro-tagged, phosphine-free palladium nanoparticles supported on silica gel: application to alkynylation of aryl halides, Suzuki–Miyaura cross-coupling, and Heck reactions under aerobic conditions
cross-coupling, as well as in the Heck reaction between methyl acrylate and aryl iodides is described. The reactions are carried out under aerobic and phosphine-free conditions with excellent to quantitative product yields in each case. The catalysts are easily recovered and reused several times without significant loss of activity. The alkynylation of aryl halides (under copper-free conditions) and the Suzuki–Miyaura
Iron catalysis for the synthesis of ligands: Exploring the products of hydrophosphination as ligands in cross-coupling
作者:Maialen Espinal-Viguri、Mary F. Mahon、Simon N.G. Tyler、Ruth L. Webster
DOI:10.1016/j.tet.2016.11.058
日期:2017.1
Catalytic hydrophosphination is a useful technique for the synthesis of phosphines, however, the phosphine products have been little exploited as ligands in catalysis. We have selected three phosphines prepared by iron catalyzed hydrophosphination and used them as ligands in a series of cross-coupling reactions: Heck, Suzuki-Miyaura and Buchwald-Hartwig. Rather than limit the chemistry to simple cross-coupling
APPLICATION OF METAL HYDRIDE/PALLADIUM COMPOUND SYSTEM IN PREPARATION OF 1,3-DICARBONYL COMPOUND IN CASCADE REACTION OF ELECTRON-DEFICIENT ALKENE COMPOUND
申请人:SOOCHOW UNIVERSITY
公开号:US20210206707A1
公开(公告)日:2021-07-08
Provided is an application of a metal hydride/palladium compound system in the preparation of a 1,3-dicarbonyl compound in a cascade reaction of an electron-deficient alkene compound, said reaction comprising the following steps: under the protection of nitrogen, a palladium compound and a metal hydride are suspended and stirred in a solvent, then an electron-deficient alkene compound is added; the mixture reacts at 0° C. to 100° C. for 0.3 to 10 hours; a saturated ammonium chloride aqueous solution is added to stop the reaction, and then extraction, drying by evaporation and purification by column chromatography are performed to obtain the product of 1,3-dicarbonyl compound. The hydride and palladium compound catalysts used in the method are reagents easily obtained in a laboratory; compared with the commonly used methods of hydrogenation with hydrogen gas, the method can be easily operated, and has high safety, mild conditions and high reaction yield.
Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study
作者:Ning Yuan、Vlad Pascanu、Zhehao Huang、Alejandro Valiente、Niclas Heidenreich、Sebastian Leubner、A. Ken Inge、Jakob Gaar、Norbert Stock、Ingmar Persson、Belén Martín-Matute、Xiaodong Zou
DOI:10.1021/jacs.8b03505
日期:2018.7.5
mechanism of the Heck C-C coupling reactioncatalyzed by Pd@MOFs has been investigatedusing operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron
使用原位 X 射线吸收光谱 (XAS) 和粉末 X 射线衍射 (PXRD) 结合透射电子显微镜 (TEM) 分析和核磁共振 (1H) 研究了由 Pd@MOFs 催化的 Heck CC 偶联反应的机理。 NMR)动力学研究。使用定制的反应池,允许使用高能同步辐射进行操作 PXRD 和 XAS 数据收集。通过结合非原位研究分析 XAS 数据,可以跟踪钯物种从合成状态到失活形式的演变。提出了一种自适应反应机制。发现单核 Pd(II) 配合物是反应开始时的主要活性物质,然后在随后的催化转换中逐渐转变为平均具有 13-20 个 Pd 原子的 Pd 纳米团簇。可用试剂和底物的消耗导致 Cl- 离子与其表面配位,从而导致活性位点中毒。通过了解失活过程,可以调整反应条件并延长催化剂的寿命。