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Öğe {1,3-bis(3,4,5-trimethoxybenzyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene} chloro(eta(4)-cycloocta-1,5-diene)rhodium(I)(Int Union Crystallography, 2007) Arslan, Hakan; VanDerveer, Don; Ozdemir, Ismail; Demir, Serpil; Cetinkaya, BekirIn the title complex, [RhCl(C8H12)(C24H32N2O6)], the Rh atom is coordinated by a Cl atom, one C atom of the tetrahydropyrimidine ring and the two double bonds of cyclooctadiene. Each of the tetrahydropyrimidine and cyclooctadiene rings is puckered.Öğe 1-(1H-Benzimidazol-1-ylmethyl)-3-[2-(diisopropylamino)ethyl]-1H-benzimidazolium bromide 0.25-hydrate(Wiley-Blackwell, 2009) Arslan, Hakan; VanDerveer, Don; Demir, Serpil; Oezdemir, Ismail; Cetinkaya, BekirThe title N-heterocyclic carbene derivative, C23H30N5+center dot Br-center dot 0.25H(2)O, was synthesized using microwave heating and was characterized by H-1 and C-13 NMR spectroscopy and a single-crystal X-ray diffraction study. The structure of the title compound are stabilized by a network of intra-and intermolecular C-H center dot center dot center dot Br hydrogen-bonding interactions. The crystal structure is further stabilized by pi-pi stacking interactions between benzene and imidazole fragment rings of parallel benzo[d] imidazole rings, with a separation of 3.486 (3) angstrom between the centroids of the benzene and imidazole rings. There is also an intermolecular C-H center dot center dot center dot pi interaction in the crystal structure. The C-N bond lengths for the central benzimidazole ring are shorter than the average single C-N bond, thus showing varying degrees of double-bond character and indicating partial electron delocalization within the C-N-C-N-C fragment. The isopropyl group is disordered over two sites with occupancies of 0.792 (10) and 0.208 (10).Öğe 1-(4-tert-Butylbenzyl)-3-(3,4,5-trimethoxybenzyl)benzimidazolium bromide monohydrate(Wiley-Blackwell Publishing, Inc, 2009) Arslan, Hakan; VanDerveer, Don; Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirA novel N-heterocyclic carbene derivative, C(28)H(33)N(2)O(3)(+)center dot-Br(-)center dot H(2)O, was synthesized and characterized by elemental analysis, (1)H and (13)C-NMR and IR spectroscopy and a single-crystal X- ray diffraction study. Ions of the title compound are linked by pi center dot center dot center dot pi stacking interactions (face-face separation 3.441 angstrom) and C-H center dot center dot center dot Br and O-H center dot center dot center dot Br interactions. Intra- and intermolecular C-H center dot center dot center dot O interactions are also present. The C-N bond lengths for the compound [1.329 (3), 1.325 (3), 1.389 (3) and 1.391 (3) angstrom] are all shorter than the average single C-N bond length of 1.48 angstrom, thus showing varying degrees of double-bond character.Öğe Bromido[1-(eta(6)-4-tert-butylbenzyl)-3-(2,4,6-trimethylbenzyl)benzimidazol-2-ylidene]chloridoruthenium(II)(Wiley-Blackwell, 2009) Arslan, Hakan; VanDerveer, Don; Ozdemir, Ismail; Demir, Serpil; Cetinkaya, BekirA new ruthenium complex, [RuBrCl(C28H32N2)], has been synthesized and characterized by elemental analysis, H-1 NMR, C-13 NMR, IR-spectroscopy and a single-crystal X-ray diffraction study. The Ru atom in this complex is best described as having a considerably distorted octahedral coordination environment with the arene occupying three coordination sites. Two further coordination sites are occupied by chloride and bromide ligands, while the sixth site is occupied by the carbene. The carbene portion of the ligand is a benzimidazole ring. This ring is connected to the C6H4C(CH3)(3) arene by a CH2 bridge. This leads to a system with very little apparent strain. The two halogen atoms are disordered between Br and Cl. Two partial Cl atoms share the same sites as two partial Br atoms so that the title compound effectively has one Cl and one Br atom. C-H center dot center dot center dot X (X = Cl, Br) hydrogen bonds help to stabilize the crystal structure.Öğe Chelating eta(6)-arene-eta(1)-carbene ligands in ruthenium complexes(Wiley-V C H Verlag Gmbh, 2007) Ozdemir, Ismail; Demir, Serpil; Cetinkaya, Bekir; Toupet, Loic; Castarlenas, Ricardo; Fischmeister, Cedric; Dixneuf, Pierre H.N-Heterocyclic carbene (NHC) ruthenium complexes containing a chelating NHC-eta(6)-arene ligand have been prepared and evaluated as precursors for ring opening metathesis polymerization (ROMP). The reaction of [RuCl2(p-cymene)](2) with electron-rich olefins of the bis(imidazolinylidene) type containing at least one arylmethyl-N chain (aryl: 2,4,6-trimethylphenyl, 3,4,5-trimethoxyphenyl) selectively leads, upon heating, to ruthenium(II) complexes 2 containing a chelating bridged carbene eta(6)-arene ligand. The reaction of complexes containing an additional ROCH2CH2N group with AgOTf leads to ionic complexes 5 with a tridentate trifunctional carbene/arene/ether ligand. The X-ray structure of [RuCl2{eta(1)-CN(CH2{eta 6-C6H2Me3-2,4,6})CH2CH2N(CH2-{C6H2(OMe)(3)-3,4,5})}] (2c) and that of the ionic ruthenium complex containing a trifunctional carbene/arene/ether ligand that provides ten electrons, (RuCl{eta(1)-CN(CH2{eta(6)-C6H2Me3-2,4,6})CH2CH2N(CH2CH2OCH3)}][CF3SO3] (5e), have been determined. The precursors 2 in the presence of AgOTf and propargyl alcohol, in order to produce an allenylidene initiator, and complexes 5 in the presence of propargyl alcohol lead to ROMP of norbornene. It is shown that initial chloride abstraction is required and that the catalyst activity is increased by using mesityl-ruthenium precursors and coordinated branched ether complexes. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).Öğe Novel tetrahydropyrimidinium/palladium system as a convenient catalyst: Suzuki coupling reactions of aryl chlorides(Arkat Usa Inc, 2007) Ozdemir, Ismail; Demir, Serpil; Cetinkaya, BekirFour bis(3,4,5,6-tetrahydropyrimidinium) chlorides(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( 3,4,5,6tetrahydropyrimidinium) chlorides (2a-d) and K2CO3 catalyses quantitatively the Suzuki crosscoupling of deactivated aryl chlorides.Öğe Palladium N-heterocyclic carbene complexes: Synthesis, characterization and catalytic properties in amination(Elsevier Science Sa, 2010) Ozdemir, Ismail; Demir, Serpil; Sahin, Onur; Buyukgungor, Orhan; Cetinkaya, BekirTransmetalation has proved to be a promising procedure to obtain NHC-metal complexes, which typically involves treatment of the imidazolium salt with Ag2O to form the Ag-NHC complex, followed by transmetalation to a species such as [PdCl2(CH3CN)(2)] gave the palladium complex in which the N-heterocyclic carbene was bound to the metal center. New bis(NHC)-Pd complexes were synthesized and characterized by elemental analysis, H-1 NMR, C-13 NMR, and IR spectroscopy. The crystal and molecular structure of the trans-dichlorobis{1-(2,3,5,6-tetramethylbenzyl)-3-(2,3,4,5,6-pentamethylbenzyl)imidazolidin-2-yliden}palladium(II) complex was determined by single-crystal X-ray diffraction. The activity of the Pd(II) complexes in the coupling reaction of anilines or amines with bromobenzene was investigated. A preliminary catalytic study showed that these bis(NHC)-Pd complexes were highly active in the direct synthesis of triarylamines and secondary amines in a single step. (C) 2010 Elsevier B.V. All rights reserved.Öğe Palladium(II)-NHC complexes containing benzimidazole ligand as a catalyst for C-N bond formation(Wiley, 2011) Dogan, Oznur; Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirThe reaction of 2-(2-bromoethyl)-1,3-dioxane with 1-alkylbenzimidazole derivatives results in the formation of the new benzimidazoliumsalts (1). The reaction of Pd(OAc)(2) with1,3-dialkylbenzimidazoliumsalts(1a-c) yields palladium N-heterocyclic carbene (NHC) complexes (2a-c). All synthesized compounds were characterized by (HNMR)-H-1, (CNMR)-C-13, IR and elemental analysis techniques which support the proposed structures. As catalysts, these new palladium complexes offer a simple and efficient methodology for the synthesis of triarylamines and secondary amines from anilines and amines and in a single step with potassium tertiary butoxide as a base. Copyright (C) 2010 John Wiley & Sons, Ltd.Öğe Palladium-catalyzed Heck reaction of aryl bromides in aqueous media using tris(N-heterocyclic carbene) ligands(Georg Thieme Verlag Kg, 2007) Ozdemir, Ismail; Demir, Serpil; Cetinkaya, BekirA highly effective, easy to handle and environmentally benign process for palladium-mediated Heck reaction was developed. The in situ prepared three-component system composed of palladium(II) acetate, a tris(azolinium) bromide and potassium tert-butoxide, quantitatively catalyzes the Heck reaction of aryl bromides in aqueous media.Öğe Synthesis and catalytic activity of novel xylyl-linked benzimidazolium salts(John Wiley & Sons Ltd, 2009) Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirThe reaction of 1-alkylbenzimidazole derivatives with o-/p-di(chloromethyl) benzene results in the formation of the new o-/p-xylyl-linked bis(benzimidazolium) salts, 1 and 2, respectively. The salts were characterized by NMR spectroscopy and elemental analysis. The in situ prepared complexes derived from Pd(OAc)(2)-1 and 2 exhibit catalytic activity (61-98%), to give the Heck coupling products of aryl bromides and styrene. Copyright (C) 2009 John Wiley & Sons, Ltd.Öğe Synthesis and catalytic activity of novel xylyl-linked benzimidazolium salts(John Wiley & Sons Ltd, 2009) Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirThe reaction of 1-alkylbenzimidazole derivatives with o-/p-di(chloromethyl) benzene results in the formation of the new o-/p-xylyl-linked bis(benzimidazolium) salts, 1 and 2, respectively. The salts were characterized by NMR spectroscopy and elemental analysis. The in situ prepared complexes derived from Pd(OAc)(2)-1 and 2 exhibit catalytic activity (61-98%), to give the Heck coupling products of aryl bromides and styrene. Copyright (C) 2009 John Wiley & Sons, Ltd.Öğe Synthesis and catalytic properties of novel ruthenium N-heterocyclic-carbene complexes(Elsevier Science Sa, 2009) Demir, Serpil; Oezdemir, Ismail; Cetinkaya, BekirThe reaction of [RuCl2(p-cymene)](2) with 1,3-dialkylimidazolinium salts 1a-f in the presence of a small excess of cesium carbonate yields chelated eta(6)-arene, eta(1)-carbene ruthenium complexes 2a-f. All synthesised compounds were characterized by elemental analysis, NMR spectroscopy. The catalytic activity of RuCl2(eta(6)-arene, eta(1)-imidazolinylidene) complexes 2a-f was evaluated in the direct arylation of 2-phenylpyridine with chlorobenzene derivatives. (C) 2009 Elsevier B. V. All rights reserved.Öğe Synthesis and catalytic properties of novel ruthenium N-heterocyclic-carbene complexes(Elsevier Science Sa, 2009) Demir, Serpil; Oezdemir, Ismail; Cetinkaya, BekirThe reaction of [RuCl2(p-cymene)](2) with 1,3-dialkylimidazolinium salts 1a-f in the presence of a small excess of cesium carbonate yields chelated eta(6)-arene, eta(1)-carbene ruthenium complexes 2a-f. All synthesised compounds were characterized by elemental analysis, NMR spectroscopy. The catalytic activity of RuCl2(eta(6)-arene, eta(1)-imidazolinylidene) complexes 2a-f was evaluated in the direct arylation of 2-phenylpyridine with chlorobenzene derivatives. (C) 2009 Elsevier B. V. All rights reserved.Öğe Synthesis and characterization of an N-heterocyclic carbene palladium-based complex(Int Union Crystallography, 2008) Arslan, Hakan; VanDerveer, Don; Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirÖğe Synthesis and characterization of bidentate NHC-Pd complexes and their role in amination reactions(Pergamon-Elsevier Science Ltd, 2011) Demir, Serpil; Ozdemir, Ismail; Cetinkaya, Bekir; Arslan, Hakan; VanDerveer, DonThe new well-defined and air-stable ortho-xylyl-linked N-heterocyclic carbene (NHC) Pd complexes (2a-d) have been synthesized and characterized by elemental analysis, H-1 NMR, C-13 NMR, IR spectroscopy, and single crystal X-ray diffraction studies. The palladium atom in the complex 2a lies on a crystallographic mirror plane and can be described as having a square-planar coordination environment with the carbene atoms of the benzimidazole rings of the ligand occupying two coordination sites in cis positions. Two further coordination sites are occupied by chloride ligands. The benzimidazole rings are connected to each other by an ortho-xylyl bridge. The catalytic activity of these palladium complexes has been tested in the coupling reactions of various N-containing substrates with bromobenzene. A preliminary catalytic study shows that the bis(NHC)-Pd complexes are highly active in the Buchwald-Hartwig amination reaction. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Synthesis and characterization of N-heterocyclic carbene palladium complex and its direct arylation of benzoazoles with aryl bromides application(Amer Chemical Soc, 2009) Arslan, Hakan; VanDerveer, Donald G.; Demir, Serpil; Ozdemir, Ismail; Cetinkaya, BekirÖğe Synthesis of novel rhodium-xylyl linked N-heterocyclic carbene complexes as hydrosilylation catalysts(Wiley, 2008) Oezdemir, Ismail; Demir, Serpil; Sahin, Onur; Bueyuekguengoer, Orhan; Cetinkaya, BekirReaction of ortho-xylylbis(N-2,4,6-trimethylbenzylimidazolinium);xylylbis(N-butylimidazolinium) and para-xylylbis(N-2,4,6-trimethylbenzylimidazolinium); xylylbis(N-butylimidazolinium) salts with KOBut and [RhCl(COD)](2) yields ortho- and para-xylylbis{(N-alkylimidazolidin-2-ylidene)chloro(eta(4)-1,5-cyclooctadiene) rho dium(I)} complexes (2a-d). All compounds synthesized were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of the 2a and 2d were determined by X-ray crystallography. Triethylsilane reacts with acetophenone derivatives in the presence of catalytic amount of the new rhodium(I)-carbene complexes (2a-d), to give the corresponding silylethers in good yields (83-99%). Copyright (C) 2008 John Wiley & Sons, Ltd.Öğe Synthesis, Characterization and Catalytic Activity of New N-Heterocyclic Bis(carbene)ruthenium Complexes(Wiley-V C H Verlag Gmbh, 2009) Ozdemir, Ismail; Demir, Serpil; Gurbuz, Nevin; Cetinkaya, Bekir; Toupet, Loic; Bruneau, Christian; Dixneuf, Pierre H.The reaction of RuCl2(PPh3)(3) with tBuOK-deprotonated ortho-xylyl-bis(N-imidazolinium) salts 1a-d yields RuCl2(PPh3)[bis(imidazolidin-2-ylidene)] complexes (2a-d). Under similar conditions, [RuCl2(p-cymene)](2) leads to the ruthenium complex 3 containing a tridentate eta(6)-arene-dicarbene ligand. All synthesized compounds were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of 2a, 2b and 3 were determined by X-ray crystallography. The catalytic activity of RuCl2(PPh3)[bis(imidazolidin-2-ylidene)] complexes 2a-b was evaluated in the direct arylation of 2-phenylpyridine with chlorobenzene derivatives. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)Öğe Synthesis, characterization and catalytic properties of an N-heterocyclic carbene palladium-based complex(Elsevier Science Bv, 2008) Ozdemir, Ismail; Arslan, Hakan; Demir, Serpil; VanDerveer, Don; Cetinkaya, BekirA palladium(II) complex, bis[1,3-bis-(2,4,6-trimethylbenzyl)benzimidazol-2 -ylidene]palladium(II) chloride, Pd(NHC), bearing N-heterocyclic carbenes has been synthesized and characterized by elemental analysis, IR spectroscopy and H-1 and C-13 NMR spectroscopy. Crystal structure details of Pd(NHC) are also presented. The palladium centre in the complex lies on a crystallographic inversion centre and occupies a square-planar environment. with both chloride and N-heterocyclic carbene ligands adopting a trans arrangement with Cl-Pd-Cl and C-Pd-C angles are precisely 180 degrees. The palladium-carbene complex was tested as a catalyst in the Suzuki-Miyaura cross-coupling reaction. (c) 2008 Elsevier B.V. All rights reserved.Öğe Synthesis, characterization and catalytic properties of cis-dibromo{1,1 '-di[3,4,5-trimethoxybenzyl]-3,3 '-butylenedibenzimidazol-2,2 '-diylidene}palladium (II)(Elsevier Science Bv, 2011) Ozdemir, Ismail; Arslan, Hakan; Demir, Serpil; VanDerveer, Don; Cetinkaya, BekirAn N-heterocyclic carbene palladium-based complex, cis-dibromo{1,1'-di[3,4,5-trimethoxybenzyl]1-3,3'-butylenedibenzimidazol-2,2'-diylidene}palladium(II), has been synthesized and characterized by elemental analysis, IR spectroscopy and H-1- and C-13-NMR spectroscopy. The crystal and molecular structure of the title compound was determined by single-crystal X-ray diffraction. The title compound consists of a 1,1'-di[3,4,5-trimethoxybenzyl]-3,3'-butylenedibenzimidazole and two bromo ligands coordinated to a palladium atom in a distorted square-planar cis-system. Two benzoimidazole rings are connected to each other by a C4H8 bridge. The substituted benzimidazole ligand forms a bidentate chelate with palladium, bonding via the carbene carbon atoms. There are two independent molecules A and B in the asymmetric unit. The Pd-Br bonds are 2.4675(14) and 2.4601(13) angstrom, and the Pd-C-carbene bonds are 1.985(9) and 1.986(9) angstrom for molecule A. Each A and B molecule is stabilized with intra- and inter-molecular hydrogen bonds and C-H center dot center dot center dot n interactions. The palladium-carbene complex was tested as a catalyst in the direct arylation of benzothiazole with arylbromides. The most suitable reaction conditions for the direct arylation of benzothiazole with arylbromides are NMP, K3PO4, Pd-NHC and 130 degrees C. (C) 2011 Elsevier B.V. All rights reserved.