NMR Quantification of Halogen-Bonding Ability To Evaluate Catalyst Activity
摘要:
Quantification of halogen-bonding abilities is described for a series of benzimidazolium-, imidazolium- and bis(imidazolium) halogen-bond donors (XBDs) using P-31 NMR spectroscopy. The measured Delta delta(P-31) values correlate with calculated activation free energy Delta G(double dagger) and catalytic activity for a Friedel-Crafts indole addition. This rapid method also serves as a sensitive indicator for Bronsted acid impurities.
prepared and anchored with copper salts for use as the catalyst for the Ullmann C–X couplingreaction. The Schiff-basic chitosan supported coppercomplex (PCCS@CuI) exhibits the highest catalytic activity. The structure of the catalyst was characterized by FTIR spectroscopy, TG, XRD, SEM, EDS and XPS. This catalyst exhibited high applicability for the C–N and C–S couplingreactions, in which good to excellent
A bi-functional sugar-based surfactant ALA14 was designed as the ligand and micelle constructor and demonstrated to promote the copper-catalyzed C–X coupling reaction in water. The nature of this micelle, formed by sugar-based surfactants, was investigated with CMC, DLS, and TEM, by which encapsulation and aggregation of the substrates in micelles were verified. Additionally, it was addressed by 1H-NMR
Synthesis and Physical Properties of Tunable Aryl Alkyl Ionic Liquids (TAAILs)
作者:Swantje Lerch、Thomas Strassner
DOI:10.1002/chem.202102545
日期:2021.11.5
Tunablearylalkylionicliquids (TAAILs) based on the imidazolium cation were first reported in 2009. Since then, a series of TAAILs with different properties due to the electron-donating or -withdrawing effect of the substituents at the aryl ring has been developed. Herein, a wide variety of those ionicliquids (ILs) is presented in terms of their cation structure. The authors synthesized ILs containing
2009 年首次报道了基于咪唑鎓阳离子的可调谐芳烷基离子液体 (TAAIL)。此后,由于芳环上取代基的给电子或吸电子作用,开发了一系列具有不同性质的 TAAIL。在本文中,根据它们的阳离子结构呈现了多种这些离子液体 (IL)。作者合成了含有溴化物或双(三氟甲烷)磺酰亚胺阴离子和 1-芳基-3-烷基咪唑鎓阳离子的离子液体,在苯环的邻位和/或对位具有各种取代基以及不同长度的烷基链,从丁基到十二烷基不等. 根据它们的结构报告了这些 IL 的物理性质(熔点、热分解、粘度、电化学窗口)的差异。
Framework-Copper-Catalyzed C−N Cross-Coupling of Arylboronic Acids with Imidazole: Convenient and Ligand-Free Synthesis of N-Arylimidazoles
作者:Nainamalai Devarajan、Palaniswamy Suresh
DOI:10.1002/cctc.201600480
日期:2016.9.21
A convenient and environmentally benign synthesis of N‐arylimidazoles has been demonstrated by a straightforward reaction catalyzed by the unsaturated coordination sites of Cu in the copper terephthalate metal–organic framework (Cu(tpa)‐MOF). A series of N‐arylimidazoles has been synthesized in excellent yields by the C−N cross‐coupling reaction of arylboronic acids and imidazoles catalyzed by the
A Newly Designed Carbohydrate-Derived Alkylamine Promotes Ullmann Type C–N Coupling Catalyzed by Copper in Water
作者:Xin Ge、Hua-Jun Fan、Guoquan Zhou、Wen Chen、Shihui Zhang、Xuemin Liu、Zehui Yang
DOI:10.1055/s-0037-1611695
日期:2019.1
biodegradable carbohydrate-derived alkylamine was designed and employed as ligand for Ullmann type C–N coupling catalyzed by copper in water. The coupling of aryl iodide and N-nucleophiles were examined and moderate to excellent yields were obtained. In addition, the in-water coupling strategy was expanded successfully to the reaction of indoles with 4-iodoanisole. By measuring the solubility, it is speculated