本文中,描述了通过喹啉和相关的N-杂芳烃的氢化来制备广泛的有价值的N-杂环产物的一般方案。有趣的是,N的催化加氢当存在其他容易还原的官能团,包括烯烃,酮,氰化物,羧酸,酯和酰胺时,对-杂芳烃环进行化学选择。成功催化的关键在于使用由富含地球的金属前体水热合成的纳米层钴钼硫化钼催化剂。这种非均相系统显示出可调节的相组成,可实现催化剂再生。它的催化活性取决于硫化钴混合相的组成(存在Co 3 S 4时会更高),也可能与瞬时Co-Mo-S结构的存在有关,该结构在第一次催化运行后主要消失。
A General Catalyst Based on Cobalt Core–Shell Nanoparticles for the Hydrogenation of N‐Heteroarenes Including Pyridines
作者:Kathiravan Murugesan、Vishwas G. Chandrashekhar、Carsten Kreyenschulte、Matthias Beller、Rajenahally V. Jagadeesh
DOI:10.1002/anie.202004674
日期:2020.9.28
core–shell based nanoparticles prepared by template synthesis of cobalt‐pyromellitic acid on silica and subsequent pyrolysis. The optimal catalyst material allows for general and selective hydrogenation of pyridines, quinolines, and other heteroarenes including acridine, phenanthroline, naphthyridine, quinoxaline, imidazo[1,2‐a]pyridine, and indole under comparably mild reaction conditions. In addition
在此,我们报道了通过二氧化硅上钴均苯四酸的模板合成和随后的热解制备的特定二氧化硅负载的Co/Co 3 O 4核壳纳米粒子的合成。最佳的催化剂材料允许在相对温和的反应条件下对吡啶、喹啉和其他杂芳烃(包括吖啶、菲咯啉、萘啶、喹喔啉、咪唑并[1,2-a]吡啶和吲哚)进行全面和选择性氢化。此外,还展示了这些钴纳米颗粒的回收利用及其脱氢催化能力。
A Convenient Procedure for the Oxidative Dehydrogenation of N-Heterocycles Catalyzed by FeCl2/DMSO
A convenient catalytic procedure has been developed for the oxidativedehydrogenations of N-heterocycles. Combining catalytic FeCl2 with DMSO yields a catalyst that promotes the dehydrogenation of tetrahydroquinolines and related heterocycles under 1 bar of O2, affording the corresponding N-heteroaromatic products in moderate yields.
spectroscopy, the synthesized material is composed of Fe(0), Fe3C and FeNx in a N-doped carbon matrix. The decent catalytic activity of this robust and easily recyclable Fe-material allowed for the selective hydrogenation of various (iso)quinoline derivatives, even in the presence of reducible functional groups, such as nitriles, halogens, esters and amides. For a proof-of-concept, this nanostructured
通过应用氮掺杂碳改性铁基催化剂,实现了N-杂芳烃,特别是(异)喹诺酮类化合物的受控加氢。活性的关键是通过热解碳浸渍复合材料制备催化剂,该复合材料由乙酸铁( II )和N-芳基亚氨基吡啶获得。 TEM、XRD、XPS 和拉曼光谱表明,合成的材料由 N 掺杂碳基体中的 Fe(0)、Fe 3 C 和 FeN x组成。这种坚固且易于回收的铁材料具有良好的催化活性,即使在存在可还原官能团(例如腈、卤素、酯和酰胺)的情况下,也可以选择性氢化各种(异)喹啉衍生物。为了进行概念验证,这种纳米结构催化剂被应用于天然产物和药物先导化合物的多步合成以及光致发光材料的改性中。因此,该方法构成了具有合成重要性的取代(异)喹诺酮的第一个非均相铁催化氢化。
A General and Highly Selective Cobalt-Catalyzed Hydrogenation of N-Heteroarenes under Mild Reaction Conditions
作者:Rosa Adam、Jose R. Cabrero-Antonino、Anke Spannenberg、Kathrin Junge、Ralf Jackstell、Matthias Beller
DOI:10.1002/anie.201612290
日期:2017.3.13
Herein, a general and efficientmethod for the homogeneous cobalt‐catalyzed hydrogenation of N‐heterocycles, under mild reaction conditions, is reported. Key to success is the use of the tetradentate ligand tris(2‐(diphenylphosphino)phenyl)phosphine). This non‐noble metal catalyst system allows the selectivehydrogenation of heteroarenes in the presence of a broad range of other sensitive reducible
Low‐Temperature Nickel‐Catalyzed C−N Cross‐Coupling via Kinetic Resolution Enabled by a Bulky and Flexible Chiral
<i>N</i>
‐Heterocyclic Carbene Ligand
作者:Zi‐Chao Wang、Pei‐Pei Xie、Youjun Xu、Xin Hong、Shi‐Liang Shi
DOI:10.1002/anie.202103803
日期:2021.7.12
The transition-metal-catalyzed C−N cross-coupling has revolutionized the construction of amines. Despite the innovations of multiple generations of ligands to modulate the reactivity of the metal center, ligands for the low-temperature enantioselective amination of arylhalides remain a coveted target of catalyst engineering. Designs that promote one elementary reaction often create bottlenecks at