Ionic liquids containing plant derived benzoate as anions, exhibiting supramolecular polymeric aggregation: Impact of the aggregation on organic catalysis in aqueous medium
作者:Muhammad Naveed Javed、Imran Ali Hashmi、Shoaib Muhammad、Ahmed Bari、Syed Ghulam Musharraf、Syed Junaid Mahmood、Saima Javed、Firdous Imran Ali、Faisal Rafique、Muhammad Amjad Ilyas、Waqas Ahmed Waseem
DOI:10.1016/j.molliq.2021.116329
日期:2021.8
The supramolecular polymeric aggregation behaviour of these ILs has been studied through high-resolution electron spray ionization mass spectrometry (HR-ESI-MS). Furthermore, these ILs were applied as catalyst/phase transfer catalyst in the synthesis of tetrahydrobenzo[b]pyran and its derivatives. These reactions were conducted in aqueous medium under ultrasound assistance. The results suggested that
天然存在的苯甲酸 (BA) 衍生阴离子已被用于制备无卤素亲水性离子液体 (ILs 1-4)。这些 IL 的超分子聚合物聚集行为已通过高分辨率电子喷雾电离质谱 (HR-ESI-MS) 进行了研究。此外,这些 ILs 被用作催化剂/相转移催化剂合成四氢苯并[b]吡喃及其衍生物。这些反应在超声辅助下在水性介质中进行。结果表明,1-乙基-3-甲基咪唑鎓 2-羟基苯甲酸酯 (IL-1) 是一种高效的催化剂,在 30 分钟内产生 86.9% 的产物。此外,还研究了 ILs 的聚集行为对其催化活性的影响。
Introduction of organic/inorganic Fe<sub>3</sub>O<sub>4</sub>@MCM-41@Zr-piperazine magnetite nanocatalyst for the promotion of the synthesis of tetrahydro-4<i>H</i>-chromene and pyrano[2,3-<i>d</i>]pyrimidinone derivatives
highly dispersed in the tetrahedral environment of silica framework and piperazine is successfully attached to the surface of the nanocatalyst in connection with zirconium. The prepared nanosized reagent (10–30 nm), shows excellent catalytic activity in the synthesis of tetrahydro‐4H‐chromene and pyrano[2,3‐d]pyrimidinone derivatives. All reactions are performed under mild and completely heterogeneous
Magnetic core–shell titanium dioxide nanoparticles as an efficient catalyst for domino Knoevenagel–Michael-cyclocondensation reaction of malononitrile, various aldehydes and dimedone
Magnetic core–shell titaniumdioxide nanoparticles (Fe3O4@SiO2@TiO2) were efficiently used for the preparation of tetrahydrobenzo[b]pyran derivatives via a one-pot three component condensation reaction of various aldehydes, dimedone and malononitrile at 100 °C under solvent-free conditions. The catalyst was synthesized and characterized by several techniques including X-ray diffraction (XRD), transmission
磁性核-壳二氧化钛纳米颗粒(Fe 3 O 4 @SiO 2 @TiO 2)可通过各种浓度的醛,二甲酮和丙二腈的一锅三组分缩合反应有效地用于制备四氢苯并[ b ]吡喃衍生物。无溶剂条件下的℃。通过几种技术合成并表征了催化剂,包括X射线衍射(XRD),透射电子显微镜(TEM),场发射扫描电子显微镜(FESEM)和能量色散X射线光谱(EDX)。
Introduction of taurine (2-aminoethanesulfonic acid) as a green bio-organic catalyst for the promotion of organic reactions under green conditions
作者:Farhad Shirini、Nader Daneshvar
DOI:10.1039/c6ra15432h
日期:——
derivatives are simply prepared via a three-component reaction in the presence of taurine as the catalyst. All these reactions are performed in water, a green solvent. The advantages of using of taurine as the catalyst are it is environmentally friendly, low cost, commercially available, easy to separate from the reaction mixture, and has high reusability. Use of this catalyst results in acceptable reaction
exhibited the excellent catalytic efficiency in condensation reaction for the preparation of tetrahydrobenzo[b]pyrans under solvent-free conditions as well as in the synthesis of 2-aminothiophenes via Gewald reaction. It must be noted that, HPA supported magnetite nanoparticles catalyzed the preparation of tetrahydrobenzo[b]pyrans, whereas for Gewald reaction amine-functionalized magnetite nanoparticles acted
摘要 我们在此报告了一种新型的可磁循环催化剂,该催化剂由接枝在改性的Fe 3 O 4上的铁取代的Keggin型杂多酸(HPA)组成纳米粒子。合成的杂化纳米材料在无溶剂条件下制备四氢苯并[b]吡喃的缩合反应以及通过Gewald反应合成2-氨基噻吩中均具有优异的催化效率。必须注意的是,HPA负载的磁铁矿纳米颗粒催化了四氢苯并[b]吡喃的制备,而对于Gewald反应,胺官能化的磁铁矿纳米颗粒充当了催化剂。使用不同的表征技术,例如傅立叶变换红外(FT-IR),X射线粉末衍射(XRD),场发射扫描电子显微镜(FESEM),透射电子显微镜(TEM)和振动样品磁力计(VSM)来表征。杂化纳米材料。通过连续运行五次来确认催化剂的可重复使用性。将制得的催化剂的性能与先前报道的各种催化剂进行了比较。发现新合成的催化剂在反应时间,产率和催化剂分离容易性方面是最有效的。 图形概要