نتایج جستجو برای: heterocyclic compounds

تعداد نتایج: 232222  

2018
Vijayakumar K Sountharrajan S Suganya E

Anticancer approaches may employ change of molecular structure to enhance preventive influence of chemical agents. The present examination concerned the potential anticancer impact of modified heterocyclic compounds. A strategy was developed to combine tetrazole moieties from different diamines with 2-aminobenzoic and substituted benzoyl chloride compounds with attention to synthesis, character...

Journal: :The Journal of organic chemistry 2006
Zhaoyan Zheng Zhengkun Yu Ning Luo Xiuwen Han

Four types of N-heterocyclic ring systems were successfully constructed from the reactions of 1-alkynyl Fischer carbene complexes (OC)5M=C(OEt)C[triple bond]CPh (1) (M = Cr, W) and substituted pyrazolinones (2). Reactions of 1 with 3-methyl-2-pyrazolin-5-one (2a), 3-n-propyl-2-pyrazolin-5-one (2b), 3,4-dimethyl-2-pyrazolin-5-one (2c), 3,4-trimethylene-2-pyrazolin-5-one (2d), or 3,4-tetramethyle...

Journal: :Molecules 2018
Stefan N L Andree Abhijeet S Sinha Christer B Aakeröy

A series of tritopic N-heterocyclic compounds containing electrostatically and geometrically equivalent binding sites were synthesized and subjected to systematic co-crystallizations with selected perfluoroiodoarenes in order to map out their structural landscapes. More than 70% of the attempted reactions produced a co-crystal as indicated by IR spectroscopy. Four new crystal structures are rep...

Journal: :Molecules 2012
Dan Yuan Han Vinh Huynh

N-heterocyclic carbenes (NHCs) can be easily modified by introducing functional groups at the nitrogen atoms, which leads to versatile coordination chemistry as well as diverse catalytic applications of the resulting complexes. This article summarizes our contributions to the field of NHCs bearing different types of sulfur functions, i.e., thioether, sulfoxide, thiophene, and thiolato. The expe...

Journal: :Chemical communications 2015
Anup Bhunia Shridhar Thorat Rajesh G Gonnade Akkattu T Biju

The synthesis of deoxy-Breslow intermediates in their oxidized form has been developed via the reaction of N-heterocyclic carbenes (NHCs) with chalcones. Moreover, the initial tetrahedral adduct formed from the 1,4-addition of NHCs to chalcones is also isolated.

Journal: :The Journal of organic chemistry 2003
Mark W Hooper Masaru Utsunomiya John F Hartwig

Detailed studies have been conducted to determine the activity of palladium catalysts for the amination of five-membered heterocyclic halides and to determine the factors that control the scope of this reaction. Palladium-catalyzed aminations of the electron-rich furanyl, thiophenyl, and indolyl halides and of the related 2-halogenated thiazoles, benzimidazole, and benzoxazole have been shown t...

2007
Ghulam Qadeer Nasim Hasan Rama Javeed Akhtar Mohammad Azad Malik Madeleine Helliwell

The title compound, C(20)H(23)N(3)O(4)S, is an important biologically active heterocyclic compound. The five-membered ring is oriented with respect to the six-membered rings at dihedral angles of 78.60 (3) (trimethoxyphenyl ring) and 71.57 (3)° (methoxyphenyl ring). In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into infinite chains along the c axis.

2012
Katarzyna Gobis Henryk Foks Katarzyna Wiśniewska Maria Dąbrowska-Szponar Ewa Augustynowicz-Kopeć Agnieszka Napiórkowska Artur Sikorski

ABSTRACT A series of novel phenylsulfonyl- and 4-aminophenylsulfonyl-carboximidamides were synthesized by condensation of sulfonamides with heterocyclic methyl carbimidates obtained from heterocyclic carbonitriles and used 'at its inception.' The molecular structure of the obtained compounds is discussed. Compounds possessing heterocyclic systems with a nitrogen atom in the α position to the fu...

Journal: :Dalton transactions 2012
Johanna Tornatzky Axel Kannenberg Siegfried Blechert

The importance of unsymmetrical N-heterocyclic carbenes (uNHCs) as ligands in metal-catalyzed reactions is undeniable. While uNHCs show similar properties as compared with symmetrical NHCs, dissymmetrization allows for further fine-tuning. The introduction of chelatization, hemilability, bifunctionality, shielding effects, and chirality-transfer influences the catalyst's stability, reactivity, ...

Journal: :Organic & biomolecular chemistry 2013
Li-Rong Wen Qi-Chang Sun Hai-Liang Zhang Ming Li

A highly efficient and straightforward three-component cascade reaction was developed to synthesize benzo[g]imidazo[1,2-a]quinolinedione derivatives from heterocyclic ketene aminals (HKAs), aldehydes, and 2-hydroxy-1,4-naphthoquinone (HNQ) via Et(3)N-catalyzed tandem [3 + 2 + 1] annulation under solvent-free conditions. The reactions were very mild, convenient and highly regioselective to form ...

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