COF@Fe3O4 under hydrothermal conditions for the first time. The high surface area magnetic COF could exhibit superior catalytic activity for sustainable synthesis of trisubstituted and tetrasubstituted imidazoles and pyrroles in good to excellent yields in PEG as solvent under environmentally friendly, ambient conditions and making the overall process economical, efficient, and green. The retrievable
为环境良性过程的广泛应用设计廉价而高效的纳米多孔磁性催化剂是一个极具吸引力且具有挑战性的化学研究领域。通过三聚氰胺与对苯二醛在3,4-二羟基苯甲醛包覆磁性Fe 3 O 4纳米颗粒COF@Fe 3 O 4表面缩合反应制备新型多孔磁性共价有机骨架第一次在热液条件下。高表面积磁性 COF 可以在环境友好、环境条件下以 PEG 作为溶剂的良好收率,对三取代和四取代咪唑和吡咯的可持续合成表现出优异的催化活性,并使整个过程经济、高效和绿色。PEG中的可回收催化剂是通用的,适用于广泛的底物范围和官能团兼容性。通过FTIR、XRD、EDX和SEM光谱对COF@Fe 3 O 4的结构和形貌进行了表征。COF@Fe 3 O 4 磁性催化剂通过外部磁铁回收并使用多个循环而没有显着的催化活性损失。
An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent
A mild and highly efficient reaction for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magneticallysupported Lewis acidic deepeutecticsolvent on magneticnanoparticles (LADES@MNP) has been developed via one-pot multicomponent processes under solvent-free sonication. These reactions have good to excellent yields, mild conditions, and work-up simplicity
Treatment of benzoin with an aldehyde and NH4OAc in polyethylene glycol (PEG-400) under reflux afforded a 5-substituted 2,3-diphenyl imidazole while the same reaction along with an additional aniline produced 5-substituted 1-aryl 2,3-diphenyl imidazole. No any catalyst or solvent was required to carry out this conversion, and the imidazoles were formed in excellent yields.
Sulfonated-polyvinyl amine coated on Fe3O4 nanoparticles: a high-loaded and magnetically separable acid catalyst for multicomponent reactions
作者:Maryam Arghan、Nadiya Koukabi、Eskandar Kolvari
DOI:10.1007/s13738-019-01700-8
日期:2019.11
onto the surface of magneticnanoparticles without using organosilane precursors. In order to obtain amine-functionalized magnetic, Hofmann degradation was carried out. In the following, sulfonated-polyvinyl amine coated on Fe3O4 nanoparticles was prepared by covalent grafting of chlorosulfonic acid on amine groups. The introduction of polymer to the surface of magneticnanoparticles increases the loading
摘要在这项研究中,通过不带有机硅烷前体的丙烯酰胺在磁性纳米粒子表面上的简单且原位聚合制备了带有PVAm的SO 3 H基团/ Fe 3 O 4纳米复合材料。为了获得胺官能化的磁性,进行了霍夫曼降解。在下文中,将磺化聚乙烯胺涂覆在Fe 3 O 4上通过将氯磺酸共价接枝到胺基上制备纳米颗粒。将聚合物引入磁性纳米颗粒的表面极大地增加了带有官能团的负载量。所得的杂化材料有效地用作了无溶剂条件下一锅合成2,4,5-三取代和1,2,4,5-四取代的咪唑的空前的酸性磁性催化剂。催化剂的显着特征是高收率,温和的反应条件,较短的反应时间,操作简便且可重复使用。使用TGA,FT-IR,SEM,TEM,VSM,EDX,CHNS和XRD分析表征了新开发的催化剂的结构。可以进行催化剂的磁分离和循环至少8次,而催化活性没有任何显着降低。 图形概要
Synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles in water using p-dodecylbenzenesulfonic acid as catalyst
2,4,5-Trisubstituted imidazoles have been synthesized by treatment of benzil with aldehydes and ammonium acetate in water under reflux in the presence of p-dodecylbenzenesulfonic acid as catalyst. The same reaction using an additional amine affords 1,2,4,5-tetrasubstituted imidazoles. The products are formed in high yields within 4 h under eco-friendly conditions.