نتایج جستجو برای: substituted pyrrole

تعداد نتایج: 42480  

Journal: :Chemical communications 2011
Hiromitsu Maeda Kota Kinoshita Kazumasa Naritani Yuya Bando

Pyrrole-based π-conjugated anion-responsive molecules bearing an anionic moiety form self-complementary dimers, which exhibit self-sorting behaviours depending on the substituted positions of anionic sites.

Journal: :Organic & biomolecular chemistry 2011
Benjamin R Clark Stephen O'Connor Deirdre Fox Jacques Leroy Cormac D Murphy

The biosynthesis of the pyrrolyl moiety of the fungal metabolite rumbrin originates from pyrrole-2-carboxylic acid. In an effort to produce novel derivatives with enhanced biological activity a series of substituted pyrrole-2-carboxylates were synthesised and incubated with the producing organism, Auxarthron umbrinum. Several 4-halo-pyrrole-2-carboxylic acids were incorporated into the metaboli...

1999
Benjamin J. Littler Mark A. Miller Chen-Hsiung Hung Richard W. Wagner Donal F. O’Shea Paul D. Boyle Jonathan S. Lindsey

5-Substituted dipyrromethanes are important precursors for the synthesis of meso-substituted porphyrins,1 expanded porphyrins, and porphyrin analogues.2 Several one-flask methods have been reported for the synthesis of 5-substituted dipyrromethanes by the condensation of an aldehyde and pyrrole using various combinations of acids and solvents.3-14 We previously reported a one-flask synthesis of...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2002
Jonathan L Sessler Vladimír Král Tatiana V Shishkanova Philip A Gale

The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearing the appended cytosine attached at either a beta- or meso-pyrrolic position, is described. These systems were tested as nucleotide-selective carriers and as active components of nucleotide-sensing ion-selective electrodes at pH 6.6. Studies of carrier selectivity were made using a Pressman-type mod...

2001
Edgardo N. Durantini

5-(4-X-Phenyl)-10,15,20-tris(substituted phenyl) porphyrins (4-6) were synthesized from meso-(substituted phenyl) dipyrromethanes (1-3), which in turn were prepared in yields of 75-92 %. This synthetic pathway was compared with the binary mixed aldehyde and pyrrole condensation method. The reported dipyrromethane approach is advantageous for porphyrins substituted by –OCH3 (4) and -F (6) groups...

2017
Marcus Baumann Ian R. Baxendale

This note describes a sequence converting an oxime-substituted pyrrolidine into a trisubstituted pyrrole structure. The synthetic route is based on a double chlorination of the pyrrolidine substrate followed by the base induced formation of both an imine and a nitrile oxide functionality. The latter reacts with an immobilized thiourea to yield an isothiocyanate which upon elimination generates ...

Journal: :Organic & biomolecular chemistry 2009
Christophe Berini Nadia Pelloux-Léon Frédéric Minassian Jean-Noël Denis

The stereoselective synthesis of penmacric acid, an optically active C-4 substituted pyroglutamic acid, has been efficiently achieved through an unusual 11-step sequence starting from simple N-triisopropylsilylpyrrole. The key-steps are the initial addition of the pyrrole nucleus onto a chiral nitrone and the obtention of the pyroglutamic acid moiety by reductive hydrogenation of the pyrrole fo...

Journal: :Journal of Molecular Spectroscopy 2021

The vibrations of pyrrole, N-deuteropyrrole, N-fluoropyrrole, N-aminopyrrole and N-methylpyrrole are studied. evolution the vibrational wavenumbers pyrrole is examined, as mass nitrogen-bonded hydrogen atom artificially increased. It found that some very sensitive to substituent bonded nitrogen, this can be viewed mixing increases; however, these mixings stablilize by time a 14 mu reached. A co...

Journal: :Molecules 2012
Debasish Bandyopadhyay Jessica Cruz Ram N Yadav Bimal K Banik Banik

2-Azetidinones and pyrroles are two highly important classes of molecules in organic and medicinal chemistry. A green and practical method for the synthesis of 3-pyrrole-substituted 2-azetidinones using catalytic amounts of molecular iodine under microwave irradiation has been developed. Following this method, a series of 3-pyrrole- substituted 2-azetidinones have been synthesized with a variet...

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