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。
A facile strategy for the synthesis of highly substituted imidazole using tetrabutyl ammoniumbromide as catalyst
A simple and facile strategy for the synthesis of highly substituted imidazoles has been developed by multi-component condensation of 1,2-diketone, aldehyde, amine, and ammonium acetate in presence of tetrabutyl ammonium bromide as catalyst.
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
A series of substituted imidazoles have been synthesized in very good yield under solvent free condition by grinding 1,2-diketone, aromatic aldehyde and ammonium acetate in the presence of molecular iodine as the catalyst. The short reaction time, good yield and easy workup make this protocol practically and economically attractive and characterized by NMR spectra, X-ray, mass and CHN analysis. An excited state intramolecular proton transfer (ESIPT) process in hydroxy imidazoles (dpip and dptip) have been studied using emission spectroscopy and it was detected that the two distinct ground state rotamers are responsible for the normal and the tautomer emissions. DFT calculations on energy, dipole moment, charge distribution of the rotamers in the ground and excited states of the imidazole derivatives were performed and discussed. DFT analysis about HOMO, HOMO-1, LUMO and LUMO + 1 were carried out and discussed. PES calculation indicates that the energy barrier for the interconversion of two rotamers is too high in the excited state than the ground state.
Tetrasubstituted imidazoles were synthesized in high yields via the four-component reaction of aromatic aldehydes, amines, substituted benzils and ammonium acetate catalyzed by a porous CeO2 nanorod. Their anti-cancer activities on the Huh-7 hepatocellular carcinoma cell and antibacterial activities on four bacterial species (wild-type Escherichia coli, wild-type Staphylococcus aureus, Pseudomonas