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Öğe 2-(4-Pyridyl)-1,3-di(4-picolyl)imidazolidine(Mdpi, 2010) Yigit, Beyhan; Yigit, Murat; Ozdemir, Ismail; Cetinkaya, Bekir; Cetinkaya, EnginThe title compound was prepared by treatment of N,N'-di(4-picolyl-amino) ethane with N,N-dimethylformamide dimethylacetal in toluene and it was characterized by elemental analysis, H-1 NMR and C-13 NMR.Öğe Active ruthenium(II)-NHC complexes for alkylation of amines with alcohols using solvent-free conditions(Pergamon-Elsevier Science Ltd, 2020) Yigit, Beyhan; Karaca, Emine Ozge; Yigit, Murat; Gurbuz, Nevin; Arslan, Hakan; Ozdemir, IsmailA series of new ruthenium(II) complexes bearing N-heterocyclic carbene ligands with benzylic groups were prepared by transmetallation reactions between silver(I) N-heterocyclic carbene complexes and [RuCl2(P-cymene)](2). All of the obtained complexes were characterized by FT-IR, H-1 NMR and C-13 NMR spectroscopy, and the molecular structure of compound 3c was also determined by X-ray crystallography. These ruthenium complexes were tested for the alkylation of aromatic amines with a wide range of primary alcohols under solvent-free conditions using the hydrogen borrowing strategy. All of the compounds tested here showed excellent catalytic activity for these reactions and N-monoalkylated products were obtained selectively using 2.5 mol% of the ruthenium complexes. (C) 2019 Elsevier Ltd. All rights reserved.Öğe Amine-functionalized benzimidazolium salts: Synthesis, structural characterization, hirshfeld surface analysis and theoretical studies(Elsevier, 2021) Celepci, Duygu Barut; Yigit, Beyhan; Yigit, Murat; Ozdemir, Ismail; Aygun, MuhittinThe benzimidazolium salts were prepared by quaternazition of 1-(2-diisopropylaminoethyl)benzimidazoles in N,N-dimethylformamide with alkyl halides. The salts were characterized spectroscopically and their crystal structures were determined by the single-crystal X-ray diffraction method. The H-1 NMR and C-13 NMR and FT-IR features were also characterized by using Density Functional Theory at B3LYP level with 6-31G* basis set and were compared to the experimental ones. Detailed vibrational assignments of the wavenumbers were performed based on the potential energy distribution (PED) analysis. Quantum chemistry calculations of geometries, electronic properties (FMOs) and reactivity features of the compounds were investigated using the same level of the DFT theory. Natural bond orbital (NBO) analysis was used to analyze the stability of the molecules arising from hyperconjugative interactions and charge delocalization. Global reactivity descriptors were calculated to understand the biological activity behaviors. Additionally, the 3D Hirshfeld surfaces and the associated 2D fingerprint plots were carried out to obtain an insight into the behavior of the interactions in the compounds. A predictive study for the biological activities of the compounds was done using PASS online software and compared to the DFT results. (C) 2021 Elsevier B.V. All rights reserved.Öğe Anti-Markovnikov hydroaminations of styrene catalyzed by palladium(II) N-heterocyclic carbene complexes under conventional and microwave heating(Springer, 2018) Gok, Yetkin; Yigit, Beyhan; Celikal, Ozlem Ozeroglu; Yigit, MuratSix palladium(II) complexes with benzimidazole-based N-heterocyclic carbene ligands were synthesized by transmetallation reactions between silver(I) N-heterocyclic carbene complexes and PdCl2(PhCN)(2). The complexes were characterized by physicochemical and spectroscopic methods. The palladium complexes were tested as catalysts for intermolecular hydroamination reactions of styrene with various anilines in ionic liquids under both conventional and microwave heating. All of these complexes proved to be catalytically active in these reactions. The anti-Markovnikov addition products were selectively obtained by using 1 mol% of the palladium complex.Öğe Enhanced ?-back-donation resulting in the trans labilization of a pyridine ligand in an N-heterocyclic carbene (NHC) PdII precatalyst: a case study(Int Union Crystallography, 2019) Karabiyik, Hande; Yigit, Beyhan; Yigit, Murat; Ozdemir, Ismail; Karabiyik, HasanThe molecular structure of the benzimidazol-2-ylidene-PdCl2-pyridine-type PEPPSI (pyridine-enhanced precatalyst, preparation, stabilization and initiation) complex {1,3-bis[2-(diisopropylamino) ethyl] benzimidazol-2-ylidene-kappa C-2}dichlorido(pyridine-kappa N) palladium(II), [PdCl2(C5H5N)(C23H40N4)], has been characterized by elemental analysis, IR and NMR spectroscopy, and natural bond orbital (NBO) and charge decomposition analysis (CDA). Cambridge Structural Database (CSD) searches were used to understand the structural characteristics of the PEPPSI complexes in comparison with the usual Nheterocyclic carbene (NHC) complexes. The presence of weak C-H center dot center dot center dot Cl-type hydrogen-bond and pi-pi stacking interactions between benzene rings were verified using NCI plots and Hirshfeld surface analysis. The preferred method in the CDA of PEPPSI complexes is to separate their geometries into only two fragments, i. e. the bulky NHC ligand and the remaining fragment. In this study, the geometry of the PEPPSI complex is separated into five fragments, namely benzimidazol-2-ylidene (Bimy), two chlorides, pyridine (Py) and the Pd II ion. Thus, the individual roles of the Pd atom and the Py ligand in the donation and back-donation mechanisms have been clearly revealed. The NHC ligand in the PEPPSI complex in this study acts as a strong pi-donor with a considerable amount of pi-back-donation from Pd to Ccarbene. The electron-poor character of Pd II is supported by pi-back-donation from the Pd centre and the weakness of the Pd-N(Py) bond. According to CSD searches, Bimy ligands in PEPPSI complexes have a stronger pi-donating ability than imidazol-2-ylidene ligands in PEPPSI complexes.Öğe Imidazolinium chloride salts bearing wingtip groups: Synthesis, molecular docking and metabolic enzymes inhibition(Elsevier Science Bv, 2019) Yigit, Beyhan; Kaya, Ruya; Taslimi, Parham; Isik, Yilmaz; Karaman, Muhammet; Yigit, Murat; Ozdemir, IsmailA series of symmetrical imidazolinium chloride salts bearing secondary N-alkyl substituents were synthesized in good yield by the reaction of N,N'-dialkylethane-1,2-diamines and HC(OEt)(3) in the presence of NH4Cl. These salts were characterized by spectroscopic methods. All compounds were tested as enzyme inhibitory agents. These novel symmetrical imidazolinium chloride salts derivatives (3a-h) effectively inhibited the cytosolic hCA I and hCA II, BChE, alpha-glycosidase and AChE with K-i values in the range of 18.41-121.73 nM for hCA I, 12.50-63.12 nM for hCA II, 3.72-34.58 nM for AChE, 5.50-32.36 nM for BChE, and 94.72-364.51 nM for alpha-glycosidase, respectively. CA isoenzymes play a crucial roles including acid-base balance homeostasis by excreting and secreting protons (H+) due to the CO2 hydration, HCO3- reabsorption mechanisms, and renal NH4+ output. Also, the molecular modeling is an implementation for estimation of the binding proximity of symmetrical imidazolinium chloride salts bearing secondary wingtip groups and their inhibition mechanisms and kinetics in atomic levels at the catalytic domains. (C) 2018 Elsevier B.V. All rights reserved.Öğe INTERMOLECULAR HYDROAMINATION OF STYRENE CATALYZED BY PALLADIUM(II) N-HETEROCYCLIC CARBENE COMPLEXES IN IONIC LIQUID(Pergamon-Elsevier Science Ltd, 2016) Yigit, Beyhan; Yigit, Murat; Gok, Yetkin; Celikal, Ozlem OzerogluPdCl2(NHC)(2) complexes have been synthesized by the reaction of palladium acetate with a series of benzimidazolium and imidazolinium salts and characterized by elemental analysis, H-1 NMR and C-13 NMR spectroscopy. These complexes were used as catalysts for the intermolecular hydroamination reactions between styrene with various anilines in ionic liquid at 160 degrees C and corresponding anti-Markovnikov products were obtained with a selectivity of 100% in good yields.Öğe Novel amine-functionalized benzimidazolium salts: Synthesis, characterization, bioactivity, and molecular docking studies(Elsevier, 2020) Yigit, Murat; Yigit, Beyhan; Taslimi, Parham; Ozdemir, Ismail; Karaman, Muhammet; Gulcin, IlhamiA series of amine-tethered benzimidazolium salts were synthesized by the reactions between 1-(1-methyl-2-dimethylaminoethyl)benzimidazole and various alkyl halides. The characterization of the newly synthesized salts was done by spectroscopic methods. Also, 2e, 2f, and 2h have been docked into the catalytic active site hCA I, hCA II, AChE, BChE, and alpha-glycosidase enzymes. We have identified high binding affinity and explained inhibition mechanism of the compounds against the enzymes. These novel amine-functionalized benzimidazolium salts derivatives were good inhibitor compounds of the aglycosidase, hCA I and II isoforms, and both cholinesterase enzymes with K-i values in the range of 0.63 +/- 0.05-3.63 +/- 0.83 nM for a-glycosidase, 8.42 +/- 1.03-27.04 +/- 3.74 nM for hCA I, 7.94 +/- 0.74 - 21.82 +/- 5.81 nM for hCA II, 136.38 +/- 19.55-247.34 +/- 34.06 nM for BChE, and 124.24 +/- 13.94 - 283.55 +/- 54.06 nM for AChE, respectively. Among the inhibitors, 2e, 2e, 2f, 2f, and 2h were obtained to be the excellent inhibitors with Ki values of 8.42 +/- 1.03, 7.94 +/- 0.74,124.24 +/- 13.94,136.38 +/- 19.55, and 0.63 +/- 0.05 nM for hCA I, hCA II, AChE, BChE, alpha-glycosidase enzymes, respectively. The ability to model some metabolic enzymes receptors and theirs inhibitors in silico are important because they can save valuable resources and help to rationalize the mode of binding, and to design better inhibitors. (C) 2020 Elsevier B.V. All rights reserved.Öğe Novel Benzylic Substituted Imidazolinium, Tetrahydropyrimidinium and Tetrahydrodiazepinium Salts: Potent Carbonic Anhydrase and Acetylcholinesterase Inhibitors(Wiley-V C H Verlag Gmbh, 2018) Yigit, Beyhan; Yigit, Murat; Celepci, Duygu Barut; Gok, Yetkin; Aktas, Aydin; Aygun, Muhittin; Taslimi, ParhamThe new imidazolinium, tetrahydropyrimidinium and tetrahydrodiazepinium salts were synthesized in good yield by the reaction of the corresponding N,N'-dialkylalkanediamine with triethyl orthoformate in the presence of ammonium chloride. All of the compounds were obtained, and spectroscopically characterized. The crystal structure for the 1,3-bis(4-benzyloxy-3-methoxybenzyl)-3,4,5,6-tetrahydropyrimidinium chloride (5g) was determined by single-crystal X-ray diffraction. The biological properties of all novel compounds were tested and the influence of ring size and benzylic N-substituents on the biological activities were examined. Also, they were found as effective inhibitors against cytosolic carbonic anhydrase I and II isoforms (hCA I and II), and acetylcholinesterase (AChE) enzyme. Among these compounds, 1,3-bis(4-(1-piperidinyl)benzyl)-3,4,5,6-tetrahydropyrimidinium chloride (5f) demonstrated the the best inhibition effects against hCA I, 1,3-bis(4-benzyloxy-3-methoxybenzyl)-3,4,5,6-tetrahydropyrimidinium chloride (5g) demonstrated the the best inhibition effects against cytosolic hCA II isoenzyme. On the other hand, 1,3-Bis(4-methylthiobenzyl)-3,4,5,6-tetrahydropyrimidinium chloride, (5e) demonstrated the the best inhibition effects against AChE enzyme.Öğe Novel PEPPSI-type N-heterocyclic carbene palladium(II) complexes: Synthesis, characterization, in silico studies and enzyme inhibitory properties against some metabolic enzymes(Elsevier Science Sa, 2023) Yigit, Beyhan; Taslimi, Parham; Celepci, Duygu Barut; Taskin-Tok, Tugba; Yigit, Murat; Aygun, Muhittin; Ozdemir, IsmailIn this study, a series of PEPPSI-type N-heterocyclic carbene palladium(II) complexes 3a-e were synthesized using amine functionalized benzimidazolium salts 2a-e as N-heterocyclic carbene precursors. These complexes were characterized by FT-IR, 1H NMR and 13C NMR spectroscopy, elemental analysis and mass spectrometry. Also, the molecular and crystal structure of 3b has been determined by the single-crystal X-ray diffraction method. According to the structural analysis, the geometry of the palladium center of the complex adopts a slightly distorted square planar environment. The benzimidazolium salts 2a-e and their palladium(II) complexes 3a-e were screened for human carbonic anhydrase I, II (hCAs I and II), and alpha-glycosidase inhibitory activities. Results indicated that all the synthetic compounds exhibited potent inhibitory activities against all targets as compared to the standard inhibitors, revealed by IC50 values. Ki values of 2a-e and 3a-e for hCA I, hCA II, and alpha-glycosidase enzymes were obtained in the ranges 1.17 +/- 0.11-65.50 +/- 8.20 mu M, 1.02 +/- 0.08-57.60 +/- 6.41 mu M, and 118.86 +/- 11.92-509.21 +/- 26.61 nM, respectively. Besides these, molecular docking calculations of potent compounds 2b, 2d, 2e, 3a, 3b, 3c and 3e towards human carbonic anhydrase I (hCA I), human carbonic anhydrase II (hCA II), and alpha-glycosidase (alpha-Gly) were presented using AutoDock 4. Among the compounds discussed, compounds 3c, 3a, 2e and 2b have the best binding affinity for alpha-Gly (-9.87,-9.77,-9.04 and-8.63 kcal/mol); compounds 3e, 3b, 2d and 2e turn out to have the second-best binding affinity (-8.80,-8.74,-8.39 and-7.57 kcal/mol) against hCA II. Lastly, compounds showing the lowest binding affinity for hCA I enzyme are 3e, 3b, 2d and 2e, respectively. These findings show that especially NHC-palladium(II) complexes 3a-e are more active for all three enzyme structures than their N-heterocyclic carbene precursors 2a-e and may be potential candidates for the discovery and development of effective inhibitors for the related enzymes in the future.Öğe Palladium(II) N-heterocyclic carbene complexes as catalysts for the direct arylation of pyrrole derivatives with aryl chlorides(Elsevier Science Sa, 2017) Yigit, Beyhan; Gurbuz, Nevin; Yigit, Murat; Dagdeviren, Zeynep; Ozdemir, IsmailSilver(I) N-heterocyclic carbene complexes were synthesized in good yields by the reactions of 1,3-dialkylperhydrobenzimidazolyum salts with silver(I) oxide and used as transmetallation reagents for the synthesis of palladium(II) N-heterocyclic carbene complexes. All of the complexes were characterized using elemental analysis, H-1 NMR and C-13 NMR spectroscopy. The catalytic activity of Pd(II)-NHC complexes in the direct arylation of pyrrole derivatives was investigated. These Pd(II)-NHC complexes showed the good catalytic performance for the direct arylation of pyrrole derivatives with readily available and inexpensive aryl chlorides. The arylation reactions regioselectively produced C2- or C5-arylation products in moderate to good yields by using 1 mol% of the palladium complex. (C) 2017 Elsevier B.V. All rights reserved.Öğe PALLADIUM/BENZIMIDAZOLIUM SALT CATALYST SYSTEMS AND N-HETEROCYCLIC CARBENE-PALLADIUM(II)-PYRIDINE (PEPPSI) COMPLEXES FOR ANTI-MARKOVNIKOV HYDROAMINATIONS OF STYRENE IN IONIC LIQUID(Pergamon-Elsevier Science Ltd, 2019) Gok, Yetkin; Yigit, Beyhan; Celikal, Ozlem Ozeroglu; Yigit, MuratBoth in situ prepared Pd-NHC and NHC-Pd-PEPPSI complexes were tested as catalysts in the intermolecular hydroamination reactions between styrene with various anilines in ionic liquid. All of the compounds tested here are catalytically active for the intermolecular hydroamination of styrene with aromatic amines. The anti-Markovnikov addition products were obtained selectively by using 1 mol% of the palladium complex.Öğe Phthalimide-tethered imidazolium salts: Synthesis, characterization, enzyme inhibitory properties, and in silico studies(Wiley-V C H Verlag Gmbh, 2022) Yigit, Murat; Demir, Yeliz; Celepci, Duygu Barut; Taskin-Tok, Tugba; Arinc, Ali; Yigit, Beyhan; Aygun, MuhittinA series of new imidazolium salts were prepared in good yield by the reaction between 1-alkylimidazole and a variety of alkyl halides. The structures of the compounds were identified by FT-IR, H-1 NMR, and C-13 NMR spectroscopy, elemental analysis, and mass spectrometry. The crystal structure of 1b was determined by the single-crystal X-ray diffraction method. The phthalimide-tethered imidazolium salts exhibited inhibition abilities toward acetylcholinesterase (AChE) and human carbonic anhydrases (hCAs) I and II, with K-i values in the range of 24.63 +/- 3.45 to 305.51 +/- 35.98 nM for AChE, 33.56 +/- 3.71 to 218.01 +/- 25.21 nM for hCA I and 17.75 +/- 0.96 to 308.67 +/- 13.73 nM for hCA II. The results showed that the new imidazolium salts can play a key role in the treatment of Alzheimer's disease, epilepsy, glaucoma, and leukemia, which is related to their inhibition abilities of hCA I, hCA II, and AChE. Molecular docking and in silico absorption, distribution, metabolism, excretion and toxicity studies were used to look into how the imidazolium salts interacted with the specific protein targets. To better visualize and understand the binding positions and the influence of the imidazolium salts on hCA I, hCA II, and AChE conformations, each one was subjected to molecular docking simulations.Öğe Picolyl substituted N-heterocyclic carbene/palladium catalyzed Heck reactions(Tubitak Scientific & Technological Research Council Turkey, 2010) Yigit, Beyhan; Yigit, Murat; Ozdemir, Ismail; Cetinkaya, EnginNovel 1,3-dialkylimidazolinium and 1,3-dialkyltetrahydropyrimidinium hexafluorophosphate salts as N-heterocyclic carbene precursors were prepared by reacting N,N'-dialkylethandiamine or N,N'-dialkylpropandiamine, triethyl orthoformate, and ammonium hexafluorophosphate. The salts were characterized spectroscopically and tested in homogeneous Heck reactions.Öğe RHODIUM(I) N-HETEROCYCLIC CARBENE COMPLEXES AS CATALYSTS FOR THE ANTI-MARKOVNIKOV HYDROAMINATIONS OF STYRENE(Pergamon-Elsevier Science Ltd, 2021) Gok, Yetkin; Yigit, Beyhan; Celikal, Ozlem Ozeroglu; Yigit, MuratA series of new rhodium(I) complexes with benzimidazole based N-heterocyclic carbene (NHC) ligand were synthesized by reactions of benzimidazolium salts with [Rh(OMe)COD](2). The characterization of rhodium(I) complexes with the general formula [RhCl(NHC)(eta(4)-1,5-cyclooctadiene)] was done by physicochemical and spectroscopic methods. All the synthesized complexes were tested as catalysts in the intermolecular hydroamination reactions between styrene with aromatic amines in ionic liquid. All of these complexes tested here are catalytically active for the intermolecular hydroamination of styrene with aromatic amines in ionic liquid. The anti-Markovnikov addition products were obtained selectively by using 1 mol% of the rhodium complex.Öğe Rhodium(I) N-heterocyclic carbene complexes as catalysts for the hydrosilylation of aromatic ketones with triethylsilane(Elsevier Science Sa, 2017) Yigit, Beyhan; Yigit, Murat; Ozdemir, IsmailNew rhodium(I) N-heterocyclic carbene complexes were synthesized in good yields by the reactions of rhodium dimer [Rh(OMe) COD](2) with two equivalent of 1,3-dialkylimidazolinium chloride salts in tetrahydrofuran. All of the complexes were characterized using elemental analysis, H-1 NMR and C-13 NMR spectroscopy. These complexes were used as catalysts in the hydrosilylation of acetophenone derivatives with triethylsilane at 80 degrees C for h. These Rh(I)-NHC complexes showed the good catalytic performance for the hydrosilylation of acetophenone derivatives and the corresponding hydrosilylation products were obtained in moderate to good yields by using 1 mol% of the rhodium complex. (C) 2017 Elsevier B.V. All rights reserved.Öğe RHODIUM(I)-N-HETEROCYCLIC CARBENE-CATALYZED ADDITION OF SODIUM TETRAPHENYLBORATE TO KETONES TO FORM TERTIARY ALCOHOLS(Pergamon-Elsevier Science Ltd, 2014) Yigit, Beyhan; Yigit, Murat; Ozdemir, IsmailRhodium complexes ([Rh(COD)(NHC)Cl]) were synthesized by the reaction of bis(1,3-dialkylperhydrobenzimidazolin-2-ylidene) with [RhClCOD](2) in toluene and characterized by elemental analysis, H-1 NMR, C-13 NMR and IR spectroscopy. These complexes were used as catalysts for the addition of sodium tetraphenylborate to aromatic ketones and corresponding tertiary alcohols were obtained in good yields.Öğe Ruthenium(II) complexes bearing N-heterocyclic carbene ligands with wingtip groups and their catalytic activity in the transfer hydrogenation of ketones(Elsevier Science Sa, 2020) Yigit, Beyhan; Isik, Yilmaz; Celepci, Duygu Barut; Evren, Enes; Yigit, Murat; Gurbuz, Nevin; Ozdemir, IsmailA series of new silver(I) complexes bearing N-heterocyclic carbene (NHC) ligands with wingtip groups were synthesized by the reaction of 1,3-dialkylimidazolinium salts with silver(I) oxide in dichloromethane. The silver complexes were used as carbene-transfer agents to synthesize ruthenium(II) complexes with the general formula [RuCl2(NHC)(eta(6)-p-cymene)]. All the synthesized complexes were characterized by elemental analysis, FT-IR, H-1 NMR and C-13 NMR spectroscopy, and the molecular and crystal structure of 3d was determined by single-crystal X-ray diffraction. These ruthenium complexes were tested as catalysts in the transfer hydrogenation of ketones using (PrOH)-Pr-i as a hydrogen source. All compounds tested showed good catalytic activity in these reactions.Öğe RUTHENIUM(II) COMPLEXES WITH CHELATING N-HETEROCYCLIC CARBENES AND A RUTHENATE(II) COMPLEX AS CATALYSTS FOR THE ANTI-MARKOVNIKOV HYDROAMINATIONS OF STYRENE(Pergamon-Elsevier Science Ltd, 2021) Yigit, Murat; Gok, Yetkin; Celikal, Ozlem Ozeroglu; Yigit, BeyhanNew ruthenium chelate and ruthenate complexes were synthesized through the reaction of benzimidazolium salts and [RuCl2(p-cymene)](2) in toluene and characterized by elemental analysis, H-1 NMR and C-13 NMR spectroscopy. These ruthenium complexes were tested as catalysts in the intermolecular hydroamination reactions between styrene with aromatic amines in ionic liquid. All of these complexes tested here showed good catalytic activity in these reactions. The hydroamination reactions regioselectively produced anti-Markovnikov addition products in moderate to good yields by using 1 mol% of the ruthenium complex.Öğe Ruthenium(II)-NHC-catalyzed (NHC = perhydrobenzimidazol-2-ylidene) alkylation of amines using the hydrogen borrowing methodology under solvent-free conditions(Springer, 2019) Yigit, Murat; Karaca, Emine Ozge; Yigit, Beyhan; Gurbuz, Nevin; Ozdemir, IsmailNew ruthenium(II) complexes with N-heterocyclic carbene ligand were synthesized by transmetalation reactions between silver(I) N-heterocyclic carbene complexes and [RuCl2(p-cymene)](2). The complexes were characterized by physicochemical and spectroscopic methods. These ruthenium complexes were applied to the N-monoalkylation of aromatic amines with a wide range of primary alcohols under solvent-free conditions using the hydrogen borrowing strategy. The catalytic reactions using all ruthenium complexes resulted in N-monoalkylated products with high selectivities using furfuryl alcohol as the alkylating agent.
