نتایج جستجو برای: trisubstituted imidazoles

تعداد نتایج: 4534  

Journal: :Chemical science 2017
Jevgenijs Tjutrins Bruce A Arndtsen

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...

2017
Jevgenijs Tjutrins Bruce A. Arndtsen

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 ...

Journal: :Molecules 2015
Yukiko Matsuo Reina Takaku Yoshihiro Mimaki

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...

Khalil Pourshamsian Naser Montazeri Sadegh Asadyan

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.

Journal: :Organic & biomolecular chemistry 2012
Pei Liu Ying-Ming Pan Yan-Li Xu Heng-Shan Wang

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.

2011
Saman Damavandi

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...

Journal: :Organic & biomolecular chemistry 2015
Tarun Kumar Deepti Verma Rubem F S Menna-Barreto Wagner O Valença Eufrânio N da Silva Júnior Irishi N N Namboothiri

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...

2017
Kohei Yamada Naoto Kamimura Munetaka Kunishima

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...

Journal: :Journal of the American Chemical Society 2011
Li Huang William D Wulff

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...

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