Palladium‐Based Catalysts Supported by Unsymmetrical XYC
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Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
作者:Ankur Maji、Ovender Singh、Sain Singh、Aurobinda Mohanty、Pradip K. Maji、Kaushik Ghosh
DOI:10.1002/ejic.202000211
日期:2020.5.10
methyl)phenyl)morpholine H = dissociableproton). Molecular structure of catalysts (C1–C4) were further established by single X‐ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate
使用简单的锚定配体L 1-4 H(L 1 H = 2-(((2-(4-‐甲氧基亚苄基)-1-1-苯基肼基)),设计并合成了一系列新的不对称(XYC –1型)Palladacycles(C1 – C4))甲基)吡啶,L 2 H = N,N-二甲基-4-((2-苯基-2-(吡啶-2-基甲基)肼基)甲基)苯胺,L 3 H = N,N-二乙基-4- ((2-苯基-2-(吡啶-2-基甲基)肼基)甲基)苯胺和L 4 H = 4-(4-((2-苯基-2-(吡啶-2-基甲基)肼基)甲基)苯基吗啉H =游离质子)。催化剂的分子结构(C1 - C4)通过单X射线晶体学研究进一步确定。通过咪唑与芳基卤化物衍生物的直接Csp 2 -H芳基化研究了palladacycles(C1 - C4)的催化性能。这些palladacycles还用于研究与芳基卤化物和丙烯酸酯衍生物的Mizoroki-Heck反应。在催化循环过
Palladium–Polypyrrole Nanocomposites Pd@PPy for Direct C–H Functionalization of Pyrroles and Imidazoles with Bromoarenes
nanocomposites (Pd@PPy) with unique combination of high palladium dispersion (nanoparticle size 2.4 nm) and high palladium content (35 wt%) are efficientcatalysts for the selective arylation of substituted pyrroles and imidazoles with either activated or deactivated aryl bromides. The performances of the recoverable supportedpalladiumcatalyst matches the best performances of homogeneous systems based
4,5‐Dihydro‐imidazol‐2‐ylidene‐linked palladium complexes as catalysts for the direct CH bond arylation of azoles
作者:Murat Kaloğlu、Namık Özdemir、İsmail Özdemir
DOI:10.1002/aoc.6551
日期:——
In most of previous studies catalyzed by such complexes, unsaturated ring carbene ligands such as benzo[d]imidazol-2-ylidene and imidazol-2-ylidene were used. However, the use of saturatedring carbene ligands such as 4,5-dihydro-imidazol-2-ylidene has been highly limited. Therefore, in this study, four novel 4,5-dihydro-1H-imidazolium salts were synthesized as saturatedring carbene precursors. Then
Dimetallic Palladium‐NHC Complexes: Synthesis, Characterization, and Catalytic Application for Direct C−H Arylation Reaction of Heteroaromatics with Aryl Chlorides
作者:Jhen‐Yi Lee、Debalina Ghosh、Ya‐Ting Kuo、Hon Man Lee
DOI:10.1002/adsc.201901189
日期:2020.2.6
A series of dimetallic palladium(II)‐NHC complexes comprised of 1,4‐naphthalenyl or 9,10‐anthracenyl spacer sandwiched between two imidazole rings was successfully synthesized. These complexes were characterized by 1H and 13C1H} NMR spectroscopy and elemental analysis. The structures of two dimetallic palladium complexes and a related mononuclear palladium complex to be used for comparative studies
成功合成了一系列由1,4-萘基或9,10-蒽基间隔基夹在两个咪唑环之间的双金属钯(II)-NHC配合物。这些配合物的特征在于1 H和13 C 1 H} NMR光谱法和元素分析。X射线衍射进一步表征了用于比较研究的两种双金属钯配合物和一个相关的单核钯配合物的结构。具有9,10-蒽基连接基的双金属钯配合物在催化杂芳族化合物(咪唑,咪唑[1,2- a]吡啶和噻唑)与各种芳基氯化物,使用1.5摩尔%的中等单钯负载量。它允许有效地使用芳基氯化物来制备芳基化的杂环,以前只能与反应性较强的溴化物对应物接触。重要的是,发现双金属预催化剂的催化活性高于类似的单核配合物。
Palladium Complexes of Thio/Seleno‐Ether Containing
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‐Heterocyclic Carbenes: Efficient and Reusable Catalyst for Regioselective C‐H Bond Arylation
C1–C3 have been explored in the catalysis of C–H bond arylation of imidazoles. The protocol operates under mild reaction conditions in air with an excellent regioselective C–H bond arylation at C‐5 position in imidazoles. All the complexes were found to be efficient (yield up to 97 % in 12 h) in the catalysis; however, the activating pincer ligand framework containing Pd catalyst C3, was found to be utmost