نتایج جستجو برای: substituted pyrrole

تعداد نتایج: 42480  

Journal: :Angewandte Chemie 2012
Lindsay McMurray Elizabeth M Beck Matthew J Gaunt

Pyrrole and pyrroldine heterocycles are ubiquitous structural features in natural products. Nature’s biosynthetic machinery often synthesizes the pyrrole functionality in these molecules from a saturated pyrrolidine as part of its metabolic degradation pathway. Interestingly, the chemical synthesis of substituted pyrroles is usually more straightforward in comparison to that of the correspondin...

Journal: :ACS Sustainable Chemistry & Engineering 2022

Pyrroles are important compounds present in biological systems, used for drug synthesis and material chemistry. A typical strategy the pyrrolic ring formation is centered on Paal–Knorr reaction, where 1,4-dicarbonyl react with amines giving N-substituted pyrrole derivatives. Often, main problem of this approach availability appropriate carbonyl compounds. Here, we report a sustainable carboxyli...

Journal: :Organic & biomolecular chemistry 2011
Petr Štěpánek Ondřej Šimák Zdena Nováková Zdeněk Wimmer Pavel Drašar

We have prepared first calix[4]pyrrole containing unprotected carbohydrate moiety directly linked to meso-position of oligopyrrole by stable "C-glycosidic" bond. Basic examination of its superassembly capability is presented.

2013
Hugo Scheer Helmut Formanek

Bilin Conformation, Phycocyanin, Phycoerythrin, Phytochrome Ramachandran-type calculations are performed for conformations of bilin chromophores pres­ ent in the biliproteins phycocyanin, phycoerythrin and phytochrome. The atomic coordinates are taken from x-ray data of crystalline model compounds, namely biliverdin for pyrrole rings B, C, D and substituted succinimides for the hydrogenated rin...

Journal: :Acta poloniae pharmaceutica 2006
Jerzy Kossakowski Magdalena Pakosińska-Parys

gepirone, ipsapirone, tandospirone and others) are 1arylpiperazine derivatives with a high affinity to the 5HT1A receptor (1-3). Therefore, they are widely used in the treatment of psychotic and neurotic disorders. This paper is a continuation of our research in the field of 4aryl/heteroaryl piperazinylalkyl derivatives (4, 5) of 1(1H-pyrrole-1-ylmethyl)-10-oxa-azatricyclo[5.2.1.0] dec-8-ene-3,...

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...

2017
Xiao Meng Andrey V. Gorbunov W. S. Christian Roelofs Stefan C. J. Meskers René A. J. Janssen Martijn Kemerink Rint P. Sijbesma

We explore a new approach to organic ferroelectric diodes using a benzene-tricarboxamide (BTA) core connected with C10 alkyl chains to pyrrole groups, which can be polymerized to provide a semiconducting ferroelectric material. The compound possesses a columnar hexagonal liquid crystalline (LC) phase and exhibits ferroelectric switching. At low switching frequencies, an additional process occur...

Journal: :Dalton transactions 2004
Stephan Hartmann Rainer F Winter Biprajit Sarkar Falk Lissner

Pyrrolyl and indolyl substituted allenylidene complexes of ruthenium have been prepared from the trapping of cationic trans-[Cl(dppm)(2)Ru=C=C=C=CH(2)](+) with various pyrroles or N-methylindole. The reaction is rationalized as involving regioselective attack of the organometallic electrophile on the electron-rich heterocycle followed by proton migration to the terminal =CH(2) entity of the int...

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2014
Milena Helmer Lauer Roberta Lopes Drekener Carlos Roque Duarte Correia Marcelo Henrique Gehlen

A series of bisaryl-substituted fluorescent maleimides was synthesized via the Heck arylation. The compounds showed broad fluorescence emission bands in the visible region, a large Stokes shift in polar solvents and emission quantum yields varying from 0.04 to 0.71, depending on the structure and solvent medium. The difference in dipole moments of ground and excited electronic states of about 1...

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