نتایج جستجو برای: 5 tetrasubstituted imidazoles
تعداد نتایج: 1218724 فیلتر نتایج به سال:
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...
The Diels-Alder cycloadducts of 4-vinylimidazoles and N-phenylmaleimide are shown to undergo facile intermolecular ene reactions. Overall the reaction of three simple molecules (a diene, a dienophile and an enophile) in a two-step process gives 4,5,6,7-tetrahydro-1H-benzo[d]imidazoles with high yields, high atom economy and diastereocontrol of up to 5 new stereocentres.
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...
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...
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.
Abstract Enolates formed from 1‐phenyl‐5‐tetrazolyl β‐ketosulfones containing a tetrasubstituted α carbon centre undergo elimination to allenes with up four substituents at the cumulene unit when treated weak base (phenolate) in DMSO room temperature. The reaction is completely regioselective for allene vs diene formation nearly all investigated cases and it proceeds central‐to‐axial chirality ...
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