Simple and efficient method for the synthesis of highly substituted imidazoles using zeolite-supported reagents
作者:K. Sivakumar、A. Kathirvel、A. Lalitha
DOI:10.1016/j.tetlet.2010.04.013
日期:2010.6
Cu(II) nitrate impregnated zeolite has been used as an efficient supported reagent for an improved and rapid one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles in excellent yields. Condensation in the presence of supported reagents with operational simplicity, inexpensive reagents, high yield of products, and the use of non-toxic reagents makes this synthetic protocol
L-Proline Triflate as an Efficient and Reusable Catalyst for the One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles and 1,2,4,5-Tetrasubstituted Imidazoles
作者:Jianjun Li、Shouwang Lin、Jiajia Dai、Weike Su
DOI:10.3184/030823410x12698803608765
日期:2010.4
L-Proline triflate has been used as an efficient catalyst for an improved and rapid one-potsynthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstitutedimidazoles in good yields. The benefit of this approach is its operational simplicity and the catalyst can be easily recovered and reused without any loss of activity.
A robust and simple one-pot four component reaction for the efficient synthesis of tetrasubstituted imidazoles has been developed. In the presence of eutectic mixture stabilized iron oxide nanoparticles, the four-component reaction of aldehydes, amines, ammonium acetate, and 1,2-diphenylethane-1,2-dione proceeds smoothly at 60 °C to give a range of imidazole derivatives in moderate to good yields.
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。
Co(II) anchored glutaraldehyde crosslinked magnetic chitosan nanoparticles (MCS) for synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles
作者:Harminder Singh、Jaspreet Kaur Rajput
DOI:10.1002/aoc.3989
日期:2018.1
A simple, highly efficient and green synthesis of 2,4,5‐trisubsituted and 1,2,4,5‐tetrasubstituted imidazoles was developed using a novel MCS‐GT@Co(II) magnetically recoverable and recyclable catalyst under refluxing conditions with ethanol as a solvent. The catalyst was prepared by immobilization of chitosan onto Fe3O4 using glutaraldehyde as crosslinker followed by Co(II) ion immobilization via cobalt
使用新型MCS-GT @ Co(II)磁性可回收和可循环利用的催化剂,在乙醇回流条件下,开发了一种简单,高效且绿色的2,4,5-三取代和1,2,4,5-四取代的咪唑合成方法作为溶剂。通过使用戊二醛作为交联剂将壳聚糖固定在Fe 3 O 4上,然后通过乙酸钴固定Co(II)离子来制备催化剂。使用多种技术表征催化剂。对于有机产物的测定,1 H NMR,13使用13 C NMR和傅立叶变换红外光谱。还尝试了用催化剂的各个组分进行反应,但是在制备的催化剂中组分的协同作用显示出最高的产率和最短的反应时间。