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    1,1?,3,3?-tetraalkyl-2,2?-biperimidinylidenes
    (John Wiley & Sons Inc, 2003) Alici, B; Hökelek, T; Çetinkaya, E; Çetinkaya, B
    C-2 deprotonation of 1,3-dibutylperimidinium bromide (1a) with sodium hydride and a catalytic amount of potassium tert-butoxide in dry THF led to the formation of the exceptionally inert tetraaminoalkene 2a. In contrast, isostructural tetrakis(2-methoxyethyl)-tetraaminoalkene (2b) instantaneously reacted with O-2 to yield urea 3b, and silver nitrate was readily reduced with 2b to form a silver mirror. Compound 2a has been characterized by X-ray diffraction studies; the naphtho-pyrimidine skeleton imposes structural constraints and some rigidity to the C=C bonding. (C) 2003 Wiley Periodicals, Inc.
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    1,4,5,6-tetrahyropyrimidinium halides ligands for Suzuki-Miyaura cross-coupling of unactivated aryl chlorides
    (Pergamon-Elsevier Science Ltd, 2005) Alici, B; Özdemir, I; Gürbüz, N; Çetinkaya, E; Çetinkaya, B
    Four functionalized bis(1,4,5,6-tetrahyropyrimidinium) salts (2a-d) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle and environmentally benign process for palladium mediated Suzuki cross-coupling was developed. The in situ prepared three component system Pd(OAC)(2) / bis(1,4,5,6-tetrahyropyrimidinium) bromides (2a-d) and CS2CO3 catalyses quantitatively the Suzuki cross-coupling of deactivated aryl chloride.
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    Access to 3-methyl-4-methylene-N-tosylpyrrolidine and 3,4-dimethyl-N-tosylpyrroline by ruthenium-catalyzed cascade cycloisomerization/isomerization reactions
    (Wiley-V C H Verlag Gmbh, 2004) Özdemir, I; Çetinkaya, E; Çetinkaya, B; Çicek, M; Sémeril, D; Bruneau, C; Dixneuf, PH
    New RuCl2(benzimidazole)(arene) complexes have been prepared. Upon reaction with 1,1-diphenylprop-2-ynol they generate catalyst precursors which perform the cycloisomerization of diallyltosylamide into 3-methyl-4-methylene-N-tosylpyrrolidine. The presence of N-(2,4,6-trimethyl-benzyl)benzimidazole as ligand leads to a subsequent isomerization and gives the 3,4-dimethyl-N-tosylpyrroline. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
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    Benzimidazolin-2-ylidene-palladium-catalysed coupling reactions of aryl halides
    (Wiley, 2005) Gök, Y; Gürbüz, N; Özdemir, I; Çetinkaya, B; Çetinkaya, E
    The in situ prepared three-component system Pd(OAC)(2)-1,3-dialkylbenzimidazolium chlorides (2a-f) and CS2CO3 catalyses, quantitatively, the Suzuki cross-coupling of deactivated aryl chlorides and Heck coupling reactions of aryl bromide and iodide substrates. The 1,3-dialkylbenzimidazolium salts (2a-f) were characterized by conventional spectroscopic methods and elemental analysis. Copyright (c) 2005 John Wiley & Sons, Ltd.
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    In situ generated palladium catalysts bearing 1,3-dialkylperimidin-2-yline ligands for Suzuki reactions of aryl chlorides
    (Elsevier, 2004) Özdemir, I; Alici, B; Gürbüz, N; Çetinkaya, E; Çetinkaya, B
    Four new 1,3-dialkylperimidinium halides have been prepared and characterized. The in situ prepared three component system Pd(OAc)(2)/1,3-dialkylperimidinium (1a-d) and Cs2CO3 catalyses the Suzuki cross-coupling of deactivated aryl chloride substrates in excellent yields under mild conditions. (C) 2004 Elsevier B.V. All rights reserved.
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    In situ generated rhodium-based catalyst for addition of phenylboronic acid to aldehydes
    (Wiley-Hindawi, 2005) Yigit, M; Özdemir, I; Çetinkaya, E; Çetinkaya, B
    New 1,3-dialkylperhydrobenzimidazolinium and 1,3-dialkylimidazolinium salts (2,4) as NHC precursors have been synthesized and characterized. These salts in combination with [RhCl(COD)](2) provided active catalysts for the addition of phenylboronic acid to aldehydes under mild conditions. The in situ prepared three-component system [RhCl(COD)](2)/imidazolinium salts (2,4) and KOBu' catalyse the addition of phenylboronic acid to sterically hindered aldehydes affording the corresponding arylated secondary alcohols in good yields. (c) 2005 Wiley Periodicals, Inc.
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    In situ preparation of palladium N-heterocyclic carbene complexes and use for Suzuki reaction
    (Wiley, 2005) Özdemir, I; Gök, Y; Gürbüz, N; Çetinkaya, E; Çetinkaya, B
    The in situ prepared three component system Pd(OAc)(2), 1,3-dialkylbenzimidazolium halides (1a-e) and t-BuOK catalyses quantitatively the Suzuki cross-coupling of deactivated aryl chloride substrates. 1,3-Dialkylbenzimidazolium salts (1a-e) were characterized by conventional spectroscopic methods and elemental analyses.
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    In-situ generated functionalized benzimidazol-2-ylidene-palladium catalyst for Suzuki reaction
    (Polish Chemical Soc, 2004) Özdemir, I; Gök, Y; Gürbüz, N; Yasar, S; Çetinkaya, E; Çetinkaya, B
    From readily available starting materials functionalized 1,3-dialkylbenzimidazolium salts (la-g) have been prepared and characterized by conventional spectroscopic methods and elemental analysis. The in situ prepared three component system Pd(OAC)(2)/1,3-dialkylbenzimidazolium halides (1a-g) and Cs2CO3 catalyses Suzuki cross-coupling of aryl chloride substrates. These concepts for making catalysts in situ open the way for the discovery of many new catalysts via the interaction of commercially available metal complexes and suitable electron releasing ligands.
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    Investigation of serum minimal inhibitory concentrations of some benzimidazole, imidazole and benzothiazole derivatives and their effects on liver and renal functions
    (Ecv-Editio Cantor Verlag Medizin Naturwissenschaften, 1998) Durmaz, R; Köroglu, M; Küçükbay, H; Temel, I; Özer, MK; Refiq, M; Çetinkaya, E
    In previous studies many benzimidazole, imidazole and benzothiazole derivatives had been synthesized and their antimicrobial activities were tasted in vitro conditions. Four of these compounds showed minimal inhibitory concentrations (MIC) of 5-25 mu g/ml against standard strains and clinical isolates. In order to determine whether these four compounds can be used for therapeutic purpose, their serum MIC values and side effects on hepatic and renal functions were determined. Different concentrations of the compounds were tested on Wistar rats. Compound 1 was administered orally, intramuscularly and intravenously; compounds 2, 3 and 4 were given orally and intramuscularly. Blood samples were taken 4 and 24 h after administration of the compounds. Serum MIC Values were investigated by bioassay and serum levels of biochemical parameters by autoanalyzer. None of the tested compounds showed antimicrobial activity at their serum concentrations. Although creatinine activity was found at normal levels in all experiments, compounds 1 and 2 caused a significant increase in blood urea nitrogen (BUN) level. The values of aspartate aminotransferase and/or alanine aminotransferase and/or alkaline phosphatase which are characteristic for liver function were generally found at high levels. According to these results, it can be concluded that the tested compounds caused damage in liver and biliary tracts without antimicrobial activity by their serum concentrations.
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    Novel N-heterocyclic-carbene-rhodium complexes as hydrosilylation catalysts
    (Elsevier, 2005) Yigit, M; Özdemir, I; Çetinkaya, B; Çetinkaya, E
    Novel rhodium-1,3-dialkylperhydrobenzimidazolin-2-ylidene (2a,b) and 1,3-dialkylimidazolin-2-ylidene complexes (4a,b) have been prepared and characterized by C, H, N analysis, H-1 NMR and C-13 NMR. Triethylsilane reacts with acetophenone derivatives in the presence of catalytic amount of the new rhodium(I)-carbene complexes, RhCl(COD)(1,3-dialkylperhydrobenzimidazolin-2-ylidene) or RhCl(COD)(1,3-dialkylimidazolin-2-ylidene) to give the corresponding silylethers in good yields (63-99%). (c) 2005 Elsevier B.V. All rights reserved.
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    Novel rhodium-1,3-dialkyl-3,4,5,6-tetrahydropyrimidin-2-ylidene complexes as catalysts for arylation of aromatic aldehydes
    (Elsevier Science Sa, 2005) Özdemir, I; Demir, S; Çetinkaya, B; Çetinkaya, E
    Six new rho dium-tetrahydropyrimidin-2-ylidene complexes (2a-f) have been prepared and characterized by C, H, N analysis, H-1 NMR and C-13 NMR. Phenylboronic acid reacts with aldehydes in the presence of a catalytic amount of the new rhodium(l)-carbene complexes, RhCl(COD)(1,3-dialkyl-3,4,5,6-tetrahydropyrimidin-2-ylidene), (2a-f), to give the corresponding secondary aryl alcohols in good yields (72-96%). (c) 2005 Elsevier B.V. All rights reserved.
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    Palladium-catalyzed Suzuki reaction using 1,3-dialkylbenzimidazol-2-ylidene ligands in aqueous media
    (Wiley-Hindawi, 2004) Özdemir, I; Gök, Y; Gürbüz, N; Çetinkaya, E; Çetinkaya, B
    From readily available starting compounds, six functionalized 1,3-dialkylbenzimidazolium salts (2a-c and 4a-c) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle, and environmentally benign process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component systems Pd(OAc)(2)/1,3-dialkylbenzimidazolium chlorides and Cs2CO3 catalyze quantitatively the Suzuki cross-coupling of deactivated aryl chlorides. (C) 2004 Wiley Periodicals, Inc.
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    Palladium-catalyzed Suzuki-Miyaura reaction of aryl chlorides in aqueous media using tetrahydrodiazepinium salts as carbene ligands
    (Georg Thieme Verlag Kg, 2005) Özdemir, I; Gürbüz, N; Gök, Y; Çetinkaya, E; Çetinkaya, B
    A highly effective, easy to handle, and environmentally benign process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component system of Pd(OAc)(2), 1,3-dialkyltetrahydrodiazepinium chlorides (2a-e), and K2CO3 catalyzes quantitatively the Suzuki-Miyaura cross-coupling of deactivated aryl chloride.
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    Rhodium-benzimidazolidin-2-ylidene catalyzed addition of arylboronic acids to aldehydes
    (Springer, 2005) Özdemir, I; Gürbüz, N; Gök, Y; Çetinkaya, B; Çetinkaya, E
    Six rhodium-carbene complexes (2a-f) have been prepared and the new compounds characterized by C, H, N analyses, H-1-n.m.r. and C-13-n.m.r. Phenylboronic acid reacts with aldehydes in the presence of a catalytic amount of rhodium(I)-carbene complex, RhCl(COD)(1,3-dialkylbenzimidazolidin-2-ylidene), (2a-f), to give the corresponding aryl secondary alcohols in good yields.
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    Ruthenium(II) complexes with 2,6-pyridyl-diimine ligands
    (Elsevier Science Bv, 1999) Çetinkaya, B; Çetinkaya, E; Brookhart, M; White, PS
    Reaction of [RuCl2(p-cymene)](2) with the tridentate N-N'-N ligands, 2,6-pyridyl-diimines, led to substitution of p-cymene. The resulting complexes, believed to be coordinatively unsaturated, exhibit efficient activity for the epoxidation of cyclohexene in the presence of iodosobenzene (PhIO): the complexes formed initially take up donor molecules such as acetonitrile to achieve hexacoordination. The molecular structure for one of these, (acetonitrile){2,6-bis[1-(4-methoxyphenylimino)ethyl]pyridine}dichlororuthenium(II), 2, has been determined by X-ray diffraction. The immediate coordination sphere is a distorted octahedron with trans chloride atoms and a short Ru-N(py) (1.906 Angstrom) bond. (C) 1999 Elsevier Science B.V. All rights reserved.
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    Suzuki-Miyaura reaction of unactivated aryl chlorides using benzimidazol-2-ylidene ligands
    (Taylor & Francis Inc, 2004) Özdemir, I; Gök, Y; Gürbüz, N; Çetinkaya, E; Çetinkaya, B
    Four functionalized bis(benzimidazolium) salts (2a-d) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle, and environmentally bengin process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component system Pd(OAc)(2)/bis(benzimidazolium) bromides (2a-d) and Cs2CO3 catalyzes quantitatively the Suzuki cross-coupling of deactivated aryl chloride in aqueous media.
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    Synthesis and catalytic properties of 1-alkyl-2-imidazolineruthenium(II) complexes
    (John Wiley & Sons Ltd, 2004) Özdemir, I; Çetinkaya, B; Demir, S; Çetinkaya, E; Gürbüz, N; Çiçek, M
    New [RuCl2(imidazoline)(arene)] complexes have been prepared. The complexes were characterized by conventional spectroscopic methods and elemental analyses. Upon reaction with 1,1-diphenylprop-2-ynol they generate catalyst precursors that can perform the cycloisomerization of diallyltosylamide into N-tosyl-alpha-methylenepyrrolidine. Copyright (C) 2004 John Wiley Sons, Ltd.
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    Synthesis and catalytic properties of 1-alkylperimidineruthenium (II) complexes
    (Elsevier, 2005) Alici, B; Özdemir, I; Karaaslan, K; Çetinkaya, E; Çetinkaya, B
    Four new [RuCl2(perimidine)(p-cymene)] complexes have been prepared and characterized. Upon reaction with 1,1-diphenylprop-2-yn-1-ol they generate catalyst precursors. which perform the cycloisomerization of diallyltosylamide into N-tosyl-alpha-methylenepyrrolidine. (c) 2005 Elsevier B.V. All rights reserved.
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    Synthesis and characterisation of N-functionalized enetetramines, and their properties
    (Slovensko Kemijsko Drustvo, 2004) Gök, Y; Çetinkaya, E; Özdemir, I; Çetinkaya, B; Lappert, MF
    Two general routes are described for the synthesis of the title compounds from the reaction of, either the dimethyl acetal of N,N'-dimethylformamide and an appropriate N, N'bis(secondary amine), or sodium hydride (or potassium tert-butoxide) and 4,5-dihydroimidazolium salts. N-Functionalized enetetramines (3, 8) having 2-methoxyethyl or allyl substituent on the N-atom have been made. The reaction of this enetetramines with S-8 and Se, gave the corresponding cyclic chalcogeno ureas derivatives (4, 5). Treatment of potassium tert-butoxide with 1,1'-ethylene-3,3'-diallyldiimidazolidinium dibromide (7) afforded, either the enetetramine ( 8), or, alternatively, the amino-Claisen isomer (9). All new compounds were identified by H-1, C-13 NMR, FT-IR and micro analysis.
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    Synthesis and characterization of novel polyimides starting from 1,2-bis(p-dimethylaminobenzylideneimino)alkane homologues and various dianhydrides
    (Wiley, 2004) Koytepe, S; Gök, Y; Alici, B; Seçkin, T; Çetinkaya, E
    The objective of this research was the preparation of polyimides from 1,2-bis(p-dimethylaminophenylimino)alkane homologues and various dianhydrides in N-methylpyrrolidone by one-stage polycondensation. The monomers were prepared via condensation of p-dimethylaminobenzaldehyde and the corresponding diamines, 1,4-diaminobutane, 1,3-diaminopropane and 1,2-diaminoethane. The influence of the incorporation of this moiety into the polymer backbone on the properties of the polyimides has been evaluated. The thermogram of the polyimides indicated that PI-10 to PI-32 had T-g values ranging from 181 to 290degreesC. The inherent viscosities of the polymers ranged from 0.99 to 2.05 dl g(-1), and the highest solubility was obtained without significant loss of the thermal properties. (C) 2004 Society of Chemical Industry.