نتایج جستجو برای: trisubstituted imidazoles
تعداد نتایج: 4534 فیلتر نتایج به سال:
We describe here a tandem catalytic route to prepare imidazoles in a single operation from aryl iodides, imines and CO. The reaction involves a catalytic carbonylation of aryl halides with imines to form 1,3-dipoles, which undergo spontaneous 1,3-dipolar cycloaddition. Overall, this offers an alternative to coupling reactions to construct the (hetero)aryl-imidazole motif, where variation of the...
We describe here a tandem catalytic route to prepare imidazoles in a single operation from aryl iodides, imines and CO. The reaction involves a catalytic carbonylation of aryl halides with imines to form 1,3dipoles, which undergo spontaneous 1,3-dipolar cycloaddition. Overall, this offers an alternative to coupling reactions to construct the (hetero)aryl-imidazole motif, where variation of the ...
Examination of the bulbs of Lilium pumilum (Liliaceae) led to the isolation of four novel steroidal glycosides (1-4) with a 2,3,4-trisubstituted β-d-glucopyranosyl unit. In 1 and 3, the α-L-arabinopyranosyl moiety is linked to C-3 of the inner trisubstituted β-D-glucopyranosyl group and is present as an usual ⁴C₁ conformation. In contrast, in 2 and 4, the α-L-arabinopyranosyl moiety, which is a...
Caro’s acid-silicagel was found to be a mild and effective catalyst for the one –pot multicomponent condensation of benzyl, aldehydes and ammonium acetate used for synthesis of 2, 4, 5-trisubstituted imidazole derivatives under solvent–free conditions. This catalyst has several advantages such as simple work-up, low cost and reusability.
A convenient one-pot Mannich-type-cyclization-oxidation tandem process has been developed for the synthesis of 1,3,5-trisubstituted pyrazoles derivatives from aldehydes, hydrazines and alkynes using p-toluenesulfonic acid monohydrate (PTSA) as a multifunctional catalyst. This method provides a flexible and rapid route to 1,3,5-trisubstituted pyrazoles.
A survey of the pertinent literature reveals that aryl imidazoles have been found to possess a wide spectrum of biological activity such as antibacterial [1], antirheumatoid arthritis [2], antitubercular [3], antiviral [4], anti-inflammatory [5] and anticancer activities [6-8]. Specifically, it has been revealed from the literature that imidazoles fused with indole nucleus possess various biolo...
A one-pot, two step synthesis of highly substituted imidazoles has been carried out in good to excellent yields for the first time via a cascade intermolecular aza-SN2'-intramolecular aza-Michael addition involving a variety of Morita-Baylis-Hillman acetates of nitroalkenes and amidines in the presence of DABCO at room temperature. The synthetic and biological utility of the products has been d...
A novel method for the synthesis of trisubstituted oxazoles via a one-pot oxazole synthesis/Suzuki-Miyaura coupling sequence has been developed. One-pot formation of 5-(triazinyloxy)oxazoles using carboxylic acids, amino acids and a dehydrative condensing reagent, DMT-MM, followed by Ni-catalyzed Suzuki-Miyaura coupling with boronic acids provided the corresponding 2,4,5-trisubstituted oxazoles...
A method is described which provides for the direct asymmetric catalytic synthesis of trisubstituted aziridines from imines and diazo compounds. While unactivated imines were not reactive to α-diazo carbonyl compounds in which the diazo carbon was disubstituted, N-Boc imines react with both α-diazo esters and α-diazo-N-acyloxazolidinones to give trisubstituted aziridines with excellent diastere...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید