نتایج جستجو برای: trisubstituted imidazoles

تعداد نتایج: 4534  

2015
Yan-Li Cui Xiao-Ning Guo Ying-Yong Wang Xiang-Yun Guo

N-aryl imidazoles play an important role as structural and functional units in many natural products and biologically active compounds. Herein, we report a photocatalytic route for the C-N cross-coupling reactions over a Cu/graphene catalyst, which can effectively catalyze N-arylation of imidazole and phenylboronic acid, and achieve a turnover frequency of 25.4 h(-1) at 25°C and the irradiation...

Journal: :Molecules 2009
Yuka Kawashita Masahiko Hayashi

A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. ...

Journal: :Journal of the American Chemical Society 2005
David A Evans Keith R Fandrick Hyun-Ji Song

An enantioselective Friedel-Crafts alkylation with alpha,beta-unsaturated 2-acyl imidazoles and electron-rich aromatic nucleophiles catalyzed by bis(oxazolinyl)pyridine-scandium(III) triflate complexes has been accomplished. These alpha,beta-unsaturated 2-acyl imidazoles are effective electrophiles for the Friedel-Crafts reaction. The resulting adduct 2-acyl imidazole is easily converted to ami...

Ashraf Sadat Shahvelayati Hassan Saydi Mohammad Piltan Seyed Amir Zarei

An efficient approach to the synthesis of 1,2,3-trisubstituted indolizines is described via one-pot reactions of pyridine and dialkyl acetylendicarboxylate in the presence of ethyl 2-chloroacetoacetate in MeOH at room temperature. The corresponding 1, 2, 3-trisubstituted indolizines may be useful building blocks for the construction of complex indolizine derivatives.

2013
Gyanendra Kumar Sharma Naveen Kumar Sharma Devender Pathak

The microwave assisted and solvent free synthesis of title compounds is described in this protocol. Ten new aryl imidazoles, which are incorporated with the chemotherapeutic pharmacophores, have been synthesized by adopting one pot multicomponent reaction. First, primary aromatic or heteryl amine has been condensed with aryl or heteryl aldehydes to afford corresponding Schiff base. The Schiff b...

Imidazole is a planar, five membered heteroaromatic molecule with pyrrole type and pyridine type annular nitrogens. Several approaches are available of imidazoles from alpha halo ketones, aminonitrile, aldehyde ect. Reactivity of imidazole and benzimidazole is referred from sets of  resonance structure in which the dipolar contributors have finite importance. Imidazoles among the principal grou...

In this work a novel heterojunction catalyst have been synthesized and employed as a highly efficient catalyst for one-pot synthesis of substituted imidazoles. Analytical methods including Fourier transform infrared (FT-IR), diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Energy- dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Vibrating Sample Magnom...

2003
Varoujan A. Yaylayan Luke J.W. Haffenden

Studies with C-2-labelled glycine and alanine in model systems containing 2,3-butanedione, glyceraldehyde or glyoxal have indicated that imidazoles and oxazoles can be formed from a-dicarbonyl compounds through Strecker reaction and subsequent formation of a-amino carbonyl reactive intermediates. These intermediates can react with any aldehyde in the reaction mixture to form an imine which in t...

Journal: :Chemistry 2009
Mikhail Y Berezin Jeff Kao Samuel Achilefu

An imidazole moiety is often found as an integral part of fluorophores in a variety of fluorescent proteins and many such proteins display pH-dependent light emission. In contrast, synthetic fluorescent compounds with incorporated imidazoles are rare and have not been studied as pH probes. In this report, the richness of imidazole optical properties, including pH sensitivity, was demonstrated b...

2011
Baskar Lakshmanan Papiya Mitra Mazumder D. Sasmal Simon Santosh Jena

Anthelmintic resistance creates a major hitch over the decades throughout the world. As per WHO only few drugs are frequently used in the treatment of helminth infestations in human beings. In view of this, an attempt has been made to study the anthelmintic activity of some newly synthesized 1-substituted imidazoles (1a-1d, 2a-2d) were synthesized and characterized by their spectral data. All t...

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