نتایج جستجو برای: tetrasubstituted imidazoles

تعداد نتایج: 4152  

2015
Nicolas Gigant François Quintin Jan-E. Bäckvall

A novel protocol for the synthesis of tetrasubstituted olefins through a biomimetic approach has been explored. Both mono- and diarylations were performed under ambient oxygen pressure, giving a range of highly hindered tetrasubstituted alkenes. For diarylation of disubstituted substrates, it was demonstrated that the second arylation is the rate-limiting step of the overall transformation.

Journal: :Acta poloniae pharmaceutica 2009
Asif Husain Sushma Drabu Nitin Kumar

Disubstituted imidazoles were prepared by reacting appropriate phenylglyoxal with different aryl aldehydes in the presence of ammonium acetate. Trisubstituted imidazoles were prepared by reacting disubstituted imidazoles with chlorobenzene in the presence of catalytic amount of triethylamine (TEA). The synthesized compounds were characterized on the basis of IR, 1H-NMR and mass spectral data an...

Journal: :Molecules 2015
Yan Ran Ming Li Zong-Ze Zhang

Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. T...

2014
Debasish Bandyopadhyay Lauren C Smith Daniel R Garcia Ram N Yadav Bimal K Banik

BACKGROUND Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research. FINDINGS An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Fo...

Journal: :Advanced Synthesis & Catalysis 2021

A diastereoselective and enantioselective construction of 2,3-disubstituted 1,4-dicarbonyl compounds is reported. Nishiyama's RuPhebox complex (2.0 mol% catalyst loading) serves as a chiral Lewis acid in conjunction with BrCCl3 base for the oxidative homocoupling 2-acyl imidazoles via stereocontrolled reaction intermediate Ru enolates situ brominated imidazoles. Cleavage achiral imidazole auxil...

A one pot four-component reaction of 9,10-phenanthraquinone, aromatic aldehyde, aniline, and ammonium acetate was designed for the preparation of tetrasubstituted imidazoles (phenanthro[9,10-d]imidazole) derivatives in the presence of SBA-Pr-SO3H as a mesoporous solid acid catalyst. Phenanthro[9,10-d]imidazole derivatives were produced by the use of this technique in short reaction times and go...

2012
Mingjuan Su Stephen L. Buchwald Satoshi Ueda

The completely N1-selective Pd-catalyzed arylation of unsymmetric imidazoles with aryl halides and triflates is described. This study showed that imidazoles have a strong inhibitory effect on the in situ formation of catalytically-active Pd(0)-ligand complex. The efficacy of the N-arylation reaction was improved drastically by the use of pre-activated solution of Pd2(dba)3 and L1. From these fi...

Journal: :Green and Sustainable Chemistry 2023

Substituted imidazoles are of interest because their useful biological activities. While several methods have been developed for the synthesis such compounds, some reported utilize corrosive or toxic catalysts. We report a bismuth (III) triflate catalyzed multicomponent 2,4,5-trisubstituted imidazoles. Bismuth compounds attractive from green chemistry perspective they remarkably non-toxic and n...

2009
Ajay Kumar Dubey Neeraj Kumar Manmohan Singh Anil Pratap Singh Praveen Kumar Ashok

Di & tri substituted imidazoles were prepared by condensing phenylglyoxal with different aryl aldehydes in presence of ammonium acetate and glacial acetic acid. All the di and tri substituted imidazoles were characterized by spectral analysis i.e. HNMR and Mass spectral data. All the synthetic compounds were screened for there anti-inflammatory and anti bacterial activity.

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