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1.
ESI‐MS studies of the non‐covalent interactions between biologically important metal ions and N‐sulfonylcytosine derivatives
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Valentina Ključarić Renata Kobetić Jasmina Rinkovec Snježana Kazazić Dubravka Gembarovski Dijana Saftić Josipa Matić Željka Ban Biserka Žinić 《Journal of mass spectrometry : JMS》2016,51(11):998-1005
The aim of this report is to present the electrospray ionization mass spectrometry results of the non‐covalent interaction of two biologically active ligands, N‐1 ‐ (p‐toluenesulfonyl)cytosine, 1‐TsC, 1 and N‐1 ‐ methanesulfonylcytosine, 1‐MsC, 2 and their Cu(II) complexes Cu(1‐TsC‐N3)2Cl2, 3 and Cu(1‐MsC‐N3)2Cl2 and 4 with biologically important cations: Na+, K+, Ca2+, Mg2+ and Zn2+. The formation of various complex metal ions was observed. The alkali metals Na+ and K+ formed clusters because of electrostatic interactions. Ca2+ and Mg2+ salts produced the tris ligand and mixed ligand complexes. The interaction of Zn2+ with 1–4 produced monometal and dimetal Zn2+ complexes as a result of the affinity of Zn2+ ions toward both O and N atoms. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
A series of fused 1,3,4‐oxadiazines were regioselectively prepared in reasonable yields as major products from the reactions of the corresponding α‐carbonyl hydrazones with tetraethyl 1,3‐dithietane‐2,4‐diylidene‐bis(cyanomethylphosphonate) (1) . Side products were also observed wherein the dimeric products 8 or 17 and/or different types of N‐heterocycles such as pyrazole 24 or pyridazines 28 or 29 were isolated and identified. A comparative study on the chemistry of 1 toward α‐aminonitrile 30 is also described. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:196–204, 2000 相似文献
3.
A new method for linear polymerization of maleimides via the Diels–Alder reaction has been developed. This method involves use of a new cross‐linking agent, benzene‐3,4‐dimethylenesuccinimide, which can be generated in situ from its thiophene precursor, benzene‐2,5‐dihydrothiophene‐3,4‐dicarboximide‐S,S‐dioxide. This new cross‐linking agent is reasonably reactive, readily prepared, and stable at room temperature. A controlled molecular weight oligomer has been synthesized and applied to the polymerization to yield a highly thermal stable polyimide. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:648–652, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20249 相似文献
4.
Andrei G. Balia Aleksandr G. Belyuga Vladimir S. Brovarets Aleksandr N. Vasylenko Aleksandr V. Turov Andrei A. Gakh Boris S. Drach 《Heteroatom Chemistry》2007,18(4):432-437
Readily accessible acylamino(chloro)acetophenones, if treated with sodium rhodanide and α‐halogenocarbonyl compounds, provide 4‐acylamino‐5‐aryl‐2‐mercapto‐1,3‐oxazole derivatives which undergo recyclization on heating in polyphosphoric acid to give substituted 1,3‐thiazol‐2(3H)‐ones or 1,3‐thiazolidin‐2,4‐diones containing 2‐alkyl(aryl)‐5‐aryl‐1,3‐oxazol‐4‐yl residues at the N3 atom. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:432–437, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20317 相似文献
5.
The nitrone above is readily available via the intramolecular aza Diels-Alder reaction of an amino acid derived triene in acetic acid. Subsequent treatment of the nitrone in refluxing toluene with substituted actetylenes produced the pictured pyrrole. At lower temperatures a 2,3-dihydroisoxazole, which is the product of a 3+2 dipolar cycloaddition, is produced. Upon heating in refluxing toluene the 2,3-dihydroisoxazole is converted to the pyrrole. 相似文献
6.
Vito Fiandanese Giuseppe Marchese Angela Punzi Francesco Iannone Giacomo G. Rafaschieri 《Tetrahedron》2010,66(46):8846-8853
A convenient synthesis of 1,2,3-triazole-fused isoindolines and dihydroisoquinolines in good to excellent yield is reported, starting from easily available terminal alkynes and (2-haloaryl)alkylazides. The method is based upon a cycloaddition reaction, via click chemistry, followed by a transition metal-catalyzed functionalization of a C-H bond. 相似文献
7.
Abdou O. Abdelhamid Mervat M. Abdelhalim Gamal A. Elmegeed 《Journal of heterocyclic chemistry》2007,44(1):7-11
8.
An alternative route from 1,3-disubstituted barbituric acids to biologically relevant oxazolo[5,4-d]pyrimidine-5,7-diones was developed that features sulfonyl-azide-free (SAFE) diazo transfer and Rh2(esp)2-catalyzed cycloaddition of the resulting 5-diazobarbituric acids with aliphatic and aromatic nitriles. Besides being shorter compared to the previously described approaches, the method allows introduction of alkyl substituents at the 1,3-oxazole ring of the fused heterocyclic system. 相似文献
9.
Liang Xu 《Tetrahedron》2006,62(33):7902-7910
Various biologically important saccharin skeletons and their N-alkyl derivatives have been efficiently prepared by chromium(VI) oxide catalyzed H5IO6 oxidation of N-alkyl-o-methyl-arenesulfonamides in acetonitrile. N-tert-Butyl saccharin skeletons were easily prepared by H5IO6-CrO3 oxidation of N-tert-butyl-o-methyl arenesulfonamides in the presence of acetic anhydride. The method that furnished the novel fluoro and trifluoromethyl substituted saccharin skeletons is characterized by two steps, a simple work-up procedure, a single purification and good overall yields from substituted toluene derivatives. 相似文献
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11.
Pavel Arsenyan Kira Rubina Irina Shestakova Edgars Abele Ramona Abele Ilona Domracheva Alena Nesterova Juris Popelis Edmunds Lukevics 《应用有机金属化学》2003,17(11):825-830
New hydroselenites of the different silylalkylthio‐substituted N‐heterocycles have been prepared by the reaction of selenium dioxide with N‐heterocycles in an aqueous medium. Their structure was confirmed by 1H, 13C, and 77Se NMR data. Most of these silylalkylthio‐substituted N‐heterocycles and their hydroselenites have an expressed cytotoxic activity on the MG‐22A (mouse hepatoma), HT‐1080 (human fibrosarcoma), B16 (mouse melanoma), and Neuro 2A (mouse neuroblastoma) cell lines. Some of the hydroselenites exhibit free‐radical protection simultaneously with a high cytotoxic effect. The substances studied were also active in vivoagainst sarcoma S‐180. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
12.
Vasu K. A. Nirmala A. R. Choudhury S. Mohan J. Saravanan T. Narasimhamurthy 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o676-o678
The two title compounds, 2‐({(1Z)‐[4‐(dimethylamino)phenyl]methylene}amino)‐4,5‐dimethyl‐N‐(2‐methylphenyl)thiophene‐3‐carboxamide, C23H25N3OS, (I), and 2‐({(1E)‐[4‐(dimethylamino)phenyl]methylene}amino)‐N‐(4‐methylphenyl)‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide,C25H27N3OS, (II), show antibacterial and antifungal activities. The asymmetric unit of (II) contains two crystallographically independent molecules. The o‐toluidine ring in (I) lies gauche with respect to the thiophene ring. In (II), the p‐toluidine ring is coplanar with the thiophene ring in one molecule, but is tilted from it in the other molecule. Neither structure exhibits any significant intermolecular interactions, but in both, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation and removing conformational flexibility. 相似文献
13.
Vasu K. A. Nirmala Deepak Chopra S. Mohan J. Saravanan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o636-o638
The compounds 2‐{[(E)‐(4‐methoxyphenyl)methylene]amino}‐N‐(3‐methylphenyl)‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide, C24H24N2O2S, (I), and N‐(4‐methylphenyl)‐2‐{[(E)‐(4‐methylphenyl)methylene]amino}‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide, C24H24N2OS, (II), show antibacterial and antifungal activities. The m‐toluidine ring in (I) and the p‐toluidine ring in (II) are coplanar with their respective thiophene rings. In (I), an intermolecular C—H⋯O hydrogen bond is present, whereas (II) does not exhibit any significant intermolecular interactions. However, in both compounds, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation and eliminating conformational flexibility. 相似文献
14.
James V. Crivello Jinseo Ahn 《Journal of polymer science. Part A, Polymer chemistry》2003,41(16):2556-2569
A new, simplified method has been developed for the synthesis of S,S‐dialkyl‐S‐(dimethylhydroxyphenyl)sulfonium salt cationic photoinitiators. This novel method has successfully been used for the preparation of S,S‐dialkyl‐S‐(3,5‐dimethyl‐4‐hydroxyphenyl)sulfonium and S,S‐dialkyl‐S‐(3,5‐dimethyl‐2‐hydroxyphenyl)sulfonium salts showing a wide variation in the length and structure of the alkyl chains on the positively charged sulfur atom. These photoinitiators can also be prepared with a wide variety of different anions. The manipulation of the lengths of the alkyl chains permits the design of compatible photoinitiators for highly nonpolar monomers and oligomers such as epoxy‐functional silicones, epoxidized polybutadiene, and epoxidized vegetable oils. This article describes the synthesis and characterization of these photoinitiators. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2556–2569, 2003 相似文献
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16.
Eduard E. Nifantyev Elena N. Rasadkina Inna V. Yankovich Vitaly K. Belsky Adam I. Stash 《Heteroatom Chemistry》2000,11(2):129-137
New representatives of an original class of crown ethers—cyclopenta‐ and cyclohexaresorcinolamidophosphites—were synthesized using the molecular assemblage technique. Their thio and oxo derivatives were obtained, as well as the rhodium (I) complexes. A macrocycle containing both tri‐ and pentavalent phosphorus atoms was synthesized. 1H and 31P NMR spectroscopy data suggested the higher conformational flexibility of phosphite macrocycles as compared to phosphate ones. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:129–137, 2000 相似文献
17.
F. Serratosa 《Tetrahedron》1961,16(1-4):185-191
A new route for the preparation of patulin-oxime, and other carbonyl derivatives of patulin, in a substantial yield, starting from acetylenic compounds, is described.
Chemical and theoretical evidence is presented for stereomutation in the preparation of carbonyl derivatives from patulin. 相似文献
18.
Francesca Clerici Maria Luisa Gelmi Cristiano Monzani Donato Pocar Alessandro Sala 《Journal of heterocyclic chemistry》2006,43(4):1045-1049
19.
Sokolov V. B. Aksinenko A. Yu. Epishina T. A. Goreva T. V. 《Russian Chemical Bulletin》2010,59(4):864-866
A one-pot method for the synthesis of trifluoromethyl-containing heterocyclic pyracetam derivatives has been suggested by
the reaction of pyracetam, hexafluoroacetone, and 1,3-binucleophiles, viz., 3-aminocrotononitrile, 6-aminouracyls, 6-aminothiouracyl, N-benzyl-3-aminocyclohexenone, and 2-aminothiazoline. 相似文献
20.
James V. Crivello Jinseo Ahn 《Journal of polymer science. Part A, Polymer chemistry》2003,41(16):2570-2587
A study of the photoinitiated and thermally initiated cationic polymerizations of several monomer systems with S,S‐dialkyl‐S‐(3,5‐dimethylhydroxyphenyl)sulfonium salt (HPS) photoinitiators bearing different lengths of alkyl chains on the positively charged sulfur atom has been conducted. HPS photoinitiators are capable of photoinitiating the cationic polymerization of a wide variety of epoxy and vinyl ether monomers directly on irradiation with short‐wavelength UV light. Aryl ketone photosensitizers are effective in extending the spectral response of these photoinitiators into the long‐wavelength UV region. Kinetic studies with real‐time infrared spectroscopy show that HPS photoinitiators exhibit good efficiency in the polymerization of epoxide and vinyl ether monomers. Comparative studies also demonstrate that S,S‐dimethyl‐S‐(3,5‐dimethyl‐2‐hydroxyphenyl)sulfonium salts are more active photoinitiators than their isomeric S,S‐dimethyl‐S‐(3,5‐dimethyl‐4‐hydroxyphenyl)sulfonium salt counterparts. Both types of HPS photoinitiators display reversible photolysis as a result of facile termination reactions that take place between the growing chains ends with the photogenerated sulfur ylides. Preliminary studies have shown that HPS photoinitiators can also be employed as thermal initiators for the cationic ring‐opening polymerization of epoxides at moderate temperatures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2570–2587, 2003 相似文献