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Öğe 1,3-Dioxane Functionalized Pd-PEPPSI Catalyst for Direct Arylation of Heteroaromatics(Elsevier, 2021) Ulu, Oznur DoganA series of benzimidazolium salts (1a-d) and their Pd-PEPPSI complexes (pyridine-enhanced precatalyst preparation, stabilization, and initiation) (2a-d) were prepared to catalyze the direct arylation of heteroaromatics (2-acetylthiophene and 2-furaldehyde) with various aryl bromides. The structures of all isolated compounds were elucidated based on spectroscopic methods (H-1 and C-13 NMR, FT-IR and LC-MS spectroscopy). Under optimized reaction conditions, C5-arylated products were obtained in moderate to excellent yields in the direct arylation of heteroaromatics. (C) 2021 Elsevier B.V. All rights reserved.Öğe Alkylation of cyclic amines with alcohols catalyzed by Ru(II) complexes bearing N-Heterocyclic carbenes(Pergamon-Elsevier Science Ltd, 2018) Ulu, Oznur Dogan; Gurbuz, Nevin; Ozdemir, IsmailThis paper includes the synthesis of 2-(1,3-dioxane-2-yl)ethyl substituted benzimidazole substituted N-heterocyclic carbenes precursors and their ruthenium complexes. Synthesized compounds were characterized by elemental analysis and NMR spectroscopy. All complexes have been tested in the alkylation of pyrrolidine and morpholine with alcohols, showing an excellent activity in this reaction. (C) 2017 Published by Elsevier Ltd.Öğe Direct arylation of heteroaromatic compounds by Pd(OAc)2/tetrakis(N-benzimidazoliummethyl)benzene salt system(Arkat Usa Inc, 2021) Ulu, Oznur Dogan; Ozdemir, IsmailSix novel tetrakis(N-benzimidazoliummethyl)benzene salts were synthesized using 1,2,4,5-tetrakis(bromomethyl)benzene with 1-alkylbenzimidazole. The structures of all isolated compounds were elucidated based on spectroscopic methods (H-1 and C-13 NMR, and FT-IR spectroscopy) and were investigated for their catalytic activities in the direct arylation of 2-n-propylthiazole, 2-n-buthyltiophene, 2-n-butylfuran, and 4,5dimethylthiazole. All synthesized salts showed high catalytic activity for direct arylation of heteroaromatic compounds. [GRAPHICS]Öğe Laboratory Applications: Polymers in(Crc Press-Taylor & Francis Group, 2019) Ulu, Oznur Dogan; Ozdemir, IsmailN-Heterocyclic carbene (NHC) ligands have been successfully used in organic, inorganic, and organometallic chemistry, and over the past decades, intensive research efforts have been devoted. Herein, we aim to provide an overview of the NHC compounds supported with different polymers, and we intend to present the readers with perspectives and innovative ideas about the existing compounds and strategies in the literature. Herewith, the synthesis procedure of the supported NHC compounds is illustrated in detail. In addition, the catalytic applications of supported NHC compounds are briefly reviewed to discuss the practical use of this technique and to compare with other applications.Öğe Quantum Chemical Benchmark Study on Valdecoxib, a Potent and Selective Inhibitor of COX-2, and its Hydroxylated Derivative(2022) Serin, Sümeyya; Ulu, Oznur DoganIn this work, quantum chemical calculations were performed on valdecoxib (VLB), a highly selective and potent COX-2 inhibitor, and its hydroxylated derivative (1H-VLB), an active metabolite. The geometry optimizations and frequency calculations were carried out by using density functional theory (DFT)/B3LYP functional with the 6- 311++G (d, p) basis set. To define water phase behaviors, calculations were renewed by using universal SMD solvation model for both molecules. Structural and thermodynamic parameters, FT-IR analysis, Mulliken population analysis (MPA), frontier molecular orbital (FMO) analysis, natural bond orbital (NBO) analysis, and electrostatic surface properties were investigated in detail. Quantum chemical reactivity identifiers were calculated separately for both vacuum and water environment in order to evaluate the bioactivity tendency of both mentioned compounds. When the bioactivity of VLB and 1H-VLB molecules were compared based on quantum chemical reactivity identifiers, it was observed that the VLB molecule was more active. Moreover, druglikeness properties of studied molecules were predicted by means of Molinspiration cheminformatics software. Molecular lipophilicity potential (MLP)Öğe Synthesis of palladium complexes containing benzimidazole core and their catalytic activities in direct arylation of heteroaromatic species(Taylor & Francis Ltd, 2024) Seker, Sema; Ulu, Oznur Dogan; Gurbuz, Nevin; Ozdemir, Namik; Ozdemir, Ismail; Bulbul, HakanHerein, we report the synthesis of four new palladium complexes containing a benzimidazole core and examine their catalytic activities in the direct arylation of heteroaromatic species with aryl bromides. The complexes were characterized by H-1 and C-13 NMR spectroscopy, FT-IR spectroscopy, and elemental analysis. In the C-13 NMR spectra, NCHN peaks of Pd(II) complexes were observed between 143.2 and 144.9 ppm. Also, the structure of 2b was determined by single-crystal XRD analysis. The obtained data suggest that the lengths of the Pd-N and Pd-Cl bonds are like those of previous Pd complexes. Direct arylation reactions, using KOAc as base and DMAc as solvent under inert conditions, were carried out with the synthesized complexes in the presence of various aryl bromides, and 2-acetylthiophene, 2-furaldehyde, and 1-methylpyrole-2-carboxaldehyde. Moderate to high yields were obtained under 1% mol catalyst loading conditions. The results showed that electron-donating and electron-withdrawing substituents on the aryl halides may produce coupling products in good yields in the presence of 2a-d. These findings contribute to the synthesis and design of palladium complexes containing benzimidazole cores.Öğe SYNTHESIS, CHARACTERIZATION, AND BIOLOGICAL ACTIVITY OF 1,3-DISUBSTITUTED BENZIMIDAZOLIUM SALT AND ITS Ag-NHC COMPLEX(Soc Chemists Technologists Madeconia, 2023) Ulu, Oznur DoganIn this study, a 1,3-dioxane functionalized benzimidazole salt and its Ag-complex were synthe-sized. The prepared compounds were structurally verified by several spectroscopic techniques including 1H NMR, 13C NMR, FT-IR, LC-MS, and C, H, N analysis. Compounds were evaluated for their in vitro antioxidant activity. The salts and their Ag-NHC complexes were further evaluated for their in vitro anti-cancer activities against HCT-116 human colon cancer cells. The results showed that complex 2 exhibited high activity (4.1 times) against the cancer cell lines studied when compared to the reference drug cispla-tin. Stability studies demonstrated that these compounds are stable in aqueous and organic solutions.Öğe Synthesis, characterization, in vitro antibacterial, and anticancer studies of Ag(I)-N-heterocyclic carbene (NHC) complexes(Springer Int Publ Ag, 2023) Ulu, Oznur Dogan; Kurucay, Ali; Ates, Burhan; Ozdemir, IsmailN-Heterocyclic carbene (NHC) complexes of metals such as Ag(I), Au(I), Pd(II), and Cu(I) are very interesting compounds due to both their catalytic and biological properties. In particular, Ag(I)-NHC complexes show activity as antibacterial, antimicrobial, and anticancer agents. Therefore, in this study, six new Ag(I) complexes were obtained from the reaction of benzimidazolium salts with Ag2O. The structures of the prepared compounds were elucidated by FT-IR, H-1 NMR, C-13 NMR, LC-MS spectroscopic methods, and elemental analysis. The antibacterial activity of all Ag(I)-NHC complexes was evaluated against bacterial strains E. coli as gram-negative and B. subtilis as gram-positive bacteria using ampicillin as a standard antibiotic. Moreover, all Ag(I)-NHC complexes were investigated for anticancer activity against the breast adenocarcinoma cell line (MCF-7). All complexes showed good activity against two bacterial strains, even complexes 2d and 2e had more bactericidal activity against B. subtilis than ampicillin. Moreover, complexes 2a (IC50 6.01 +/- 2.39 mu g/mL) and 2e (IC50 3.40 +/- 0.87 mu g/mL) exhibited a better anticancer effect against to MCF-7 cell line than cisplatin (IC50 82.02 +/- 6.19 mu g/mL). Finally, it is worthy to note that the biochemical outcomes revealed that these complexes may be promising antibacterial and anticancer agents.Öğe Vibrational (FT-IR), electronic (UV-Vis), thermodynamic, and NBO analyses of amide ? imide forms of articaine: a computational perspective on prototropic tautomerism(Taylor & Francis Ltd, 2024) Serin, Suemeyya; Ulu, Oznur DoganHerein, the molecular structures of amide <-> imide tautomers of articaine (ART) were computationally investigated at the DFT/B3LYP/6-311++G (d,p) methodology. Experimental FT-IR and UV-Vis characterisation results of ART were compared with the theoretical results of amide (ART-A) and imide (ART-I) forms. Thermodynamic parameters computed for each phase revealed that the amide tautomer of ART was preferred with energy values in the range of 11.9-13.8 kcal/mol. The modification in surface properties as a function of prototropic tautomerism in the ART molecule was studied by electrostatic surface properties (ESP) analysis. Frontier molecular orbital (FMO), natural bond orbital (NBO), and nonlinear optical (NLO) analyses were performed. It is revealed that energy gap values of the ART-I (4.670-4.738 eV) for each phase are slightly higher than those of the corresponding phases in the ART-A (4.515-4.586 eV). Therefore, it can be concluded that the imide form exhibits lower chemical reactivity compared to the amide form. Regarding NLO characteristics, dipole moment (mu(tot)), mean polarisability (alpha(tot)), and mean first-order hyperpolarisability (beta(tot)) values of tautomers have been reported. It was determined that the beta(tot) values computed for ART-A (0.653 x 10(-30) esu) and ART-I (0.710 x 10(-30) esu) were approximately twice the value of the standard urea. [GRAPHICS]Öğe Water-soluble N-heterocyclic carbene precursors bearing benzimidazole core: synthesis, characterization, in vitro antioxidant and anticancer studies(Springer Wien, 2023) Ulu, Oznur Dogan; Kurucay, Ali; Ozdemir, IsmailBenzimidazole is an important member of the nitrogen-containing heterocyclic ring system since it confers surprisingly good biological properties in medicinal chemistry such as anticancer drug applications. Keeping this in mind, a new series of asymmetrical 1,3-disubstituted benzimidazolium salts were designed and reported. The compounds were synthesized by the reaction of 1-alkylbenzimidazoles with 2-(2-bromoethyl)-1,3-dioxane. The structures of all the compounds were determined using FT-IR, H-1 and C-13 NMR spectroscopy, LC-MS, and elemental analysis. The compounds were used for their antioxidant capacity by commercial kit assay. Further, these were screened for their cytotoxic effect against cell lines including MCF-7, A-549, and L929 using cisplatin as a reference drug. It resulted that the total antioxidant capacity values of the compounds were found to be quite low compared to the trolox equivalent. On the other side, most importantly, two compounds showed remarkable anticancer activity against MCF-7 and A-549 with IC50 values of 18.06 and 20.44 mu g/cm(3), respectively, in comparison with cisplatin (IC50 = 83.11 and 87.80 mu g/cm(3)). Furthermore, most of the compounds were found to be safe on normal L929 fibroblast cells compared to cancer cells (IC50 values for healthy fibroblasts were 142.70-268.37 mu g/cm(3)). Taken together, the newly synthesized compounds containing benzimidazole core can be readily constructed and used as an attractive class of anticancer agents.{graphical abstracts}
