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?6-mesityl,?1-imidazolinylidene-carbene-ruthenium(II) complexes
(Wiley-V C H Verlag Gmbh, 2003) Çetinkaya, B; Demir, S; Özdemir, I; Toupet, L; Sémeril, D; Bruneau, C; Dixneuf, PH
The reaction of electron-rich carbene-precursor olefins containing two imidazolinylidene moieties [(2,4,6-Me3C6H2CH2)NCH2CH2N(R)C=](2) (2a: R = CH2CH2OMe, 2b R = CH(2)Mes), bearing at least one 2,4,6-trimethylbenzyl (R = CH(2)Mes) group on the nitrogen atom, with [RuCl2(arene)](2) (arene = p-cymene, hexamethylbenzene) selectively leads to two types of complexes. The cleavage of the chloride bridges occurs first to yield the expected (carbene) (arene)ruthenium(H) complex 3. Then a further arene displacement reaction takes place to give the chelated eta(6)-mesityl,eta'-carbene-ruthenium complexes 4 and 5. An analogous eta(6)-arene-eta(1)-carbene complex with a benzimidazole frame 6 was isolated from an in situ reaction between [RuCl2(p-cymene)](2), the corresponding benzimidazolium salt and cesium carbonate. On heating, the RuCl2(imidazolinylidene) (p-cymene) complex 8, with p-methoxybenzyl pendent groups attached to the N atoms, leads to intramolecular p-cymene displacement and to the chelated eta(6)-arene,eta(1)-carbene complex 9. On reaction with AgOTf and the propargylic alcohol HC=CCPh20H, compounds 4-6 were transformed into the corresponding ruthenium allenylidene intermediates (4-->10, 5-->11, 6-->12). The in situ generated intermediates 10-12 were found to be active and selective catalysts for ring-closing metathesis (RCM) or cycloisomerisation reactions depending on the nature of the 1,6-dienes. Two complexes [RuCl2-{eta(1)-CN(CH2C6H2Me3-2,4,6)CH2CH2N- (CH2CH2OMe)}(C6Me6)] 3 with a monodentate carbene ligand and [RuCl2-{eta(1)-CN[CH2(eta(6)-C6H2Me3-2,4,6)]CH2CH2N-(CH2C6H2Me3-2,4,6)}] 5 with a chelating carbene-arene ligand were characterised by X-ray crystallography.
Crystal structure of [RuCl2[N-(2,4,6-trimethyl-benzyl)N-(n-butyl)]-imidazolidin-2-ylidene] and [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(2-methoxyethyl)]imidazolidin-2-ylidene]
(Springer/Plenum Publishers, 2005) Arslan, H; VanDerveer, D; Ozdemir, I; Cetinkaya, B; Demir, S
Two imidazolidin ruthenium complexes, [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(n-butyl)]imidazolidin-2-ylidene], 1, and [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(2-methoxyethyl)]imidazolidin-2-ylidene], 2, have been synthesised and their crystal structures have been determined from single crystal X-ray diffraction data. Compound I is monoclinic, of space group C2/c with a = 18.466(4) angstrom, b = 14.816(3) angstrom, c = 15.413(3) angstrom, beta = 118.067(2)degrees, and V = 3720.9(12) angstrom(3) with Z = 8 for d(calc) = 1.536 g/cm(3). Compound 2 is monoclinic, of space group P2(1)/c with a = 8.1800(5) angstrom, b = 14.344(8) angstrom, c = 14.809(9), beta = 91.604(10)degrees, and V = 1736.7(18) angstrom(3) with Z = 4 for d(calc) = 1.653 g/cm(3). In each complex the ligand functions as an arene and carbene, occupying four coordination sites. The two chlorines in each compound complete a distorted octahedron.
Crystal structure of dichloro-N-(3,4,5-trimethoxy-benzyl)-N-(n-butyl)]imidazolidin-2-ylideneruthenium(II), RuCl2(C17H26N2O3)
(R Oldenbourg Verlag, 2004) Arslan, H; Vanderveer, D; Özdemir, I; Cetinkaya, B; Demir, S
C17H26Cl2N2O3Ru, monoclinic, P12(1)/nl (no. 14), a = 10.180(1) A, b = 11.985(1) A, c = 16.017(2) A, beta = 106.419(2)degrees, V = 1874.5 A(3), Z = 4, R-gt(F) = 0.037, wR(ref)(F-2) = 0.109, T = 193 K.
First ruthenium complexes with a chelating arene carbene ligand as catalytic precursors for alkene metathesis and cycloisomerisation
(Royal Soc Chemistry, 2001) Çetinkaya, B; Demir, S; Özdemir, I; Toupet, L; Sémeril, D; Bruneau, C; Dixneuf, PH
Electron-rich carbene precursors 2 and 3, containing the imidazolidin-2-ylidene moiety with one (2) and two (3) pendent N-(2,4,6-trimethylbenzyl) groups, on reaction with [RuCl2(arene)](2) lead to ruthenium(II) complexes 5 and 6 containing the chelating 8-electron mixed arene-carbene ligand; the X-ray diffraction crystal structure of RuCl2{eta (1)- CN[CH2(eta (6)-2,4,6-Me3C6H2)]CH2CH2N(CH2CH2OMe)} 6, was established. These complexes are precursors of the unstable ruthenium-allenylidene intermediates 7 and 8, but are active catalysts either for selective catalytic alkene metathesis or cycloisomerization, depending on the nature of the 1,6-diene.
Improved palladium-catalyzed coupling reactions of aryl halides using saturated N-heterocarbene ligands
(Elsevier Science Bv, 2004) Gürbüz, N; Özdemir, I; Demir, S; Çetinkaya, B
The incorporation of saturated N-heterocyclic carbenes into palladium pre-catalysts gives high catalyst activity in the Suzuki coupling of aryl iodides, bromides and deactivated aryl chloride substrates, whereas the yield of the palladium catalyzed Heck reaction of deactivated aryl chlorides is negligible. The complexes were generated in the presence of Pd(OAc)(2) by in situ deprotonation of 1,3-dialkylimidazolinium salts LHX (1) which were characterized by conventional spectroscopic methods and elemental analyses. (C) 2003 Elsevier B.V. All rights reserved.
In situ generated 1-alkylbenzimidazole-palladium catalyst for the Suzuki coupling of aryl chlorides
(Elsevier, 2005) Özdemir, I; Sahin, N; Gök, Y; Demir, S; Çetinkaya, B
Six 1-alkylbenzimidazole have been prepared and characterized by conventional spectroscopic methods and elemental analyses. Novel in situ generated palladium-benzimidazole complexes, tested in the Suzuki coupling reaction between phenylboronic acid and several aryl chlorides showed excellent catalytic activity. (c) 2005 Elsevier B.V. All rights reserved.
In-situ generated 1-alkylimidazoline-palladium catalyst for the Suzuki cross-coupling reaction of aryl chlorides
(Taylor & Francis Inc, 2005) Özdemir, I; Sahin, N; Gürbüz, N; Demir, S; Gök, Y; Çetinkaya, B; Getinkaya, E
Five 1-alkyimidazoline (1-5) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. New in situ generated palladium-imidazoline complexes were tested for catalytic activity in the Suzuki coupling reaction between phenylboronic acid and several aryl chlorides.
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.
Novel type of metal-containing polyimides for the heck and Suzuki-Miyaura cross-coupling reactions as highly active catalysts
(Springer, 2003) Seçkin, T; Köytepe, S; Demir, S; Özdemir, I; Centinkaya, B
Novel palladium (II)-containing polyimides with exceptional catalytic properties for the Heck and Suzuki-Miyaura cross-coupling reactions were prepared from Pd(II)-alpha-bis(imine) complex and the corresponding dianhyrides. The glass transition temperatures (T-g) of the polymers ranged from 169 to 241degreesC. The temperatures at which 10% weight loss occurred in air ranged from 415 to 579degreesC. Polyimides based on the palladium (II) complex were tested for catalytic activity in the Heck coupling reaction between styrene and several aryl halides and the Suzuki coupling reaction between phenylboronic acid and several aryl halides. The negative effects (e. g., expense, low reaction rates, air-sensitivity) experienced by using phosphines, particularly electron-rich phosphines, as catalysts in large scale applications is overcome by using polymer supported catalysis.
Palladium-catalysed Suzuki reaction of aryl chlorides in aqueous media using 1,3-dialkylimidazolidin-2-ylidene ligands
(Wiley-Blackwell, 2005) Özdemir, I; Demir, S; Yasar, S; Çetinkaya, B
A highly effective, easy to handle and environmentally benign process for palladium-mediated Suzuki cross-coupling is developed. The in situ prepared three-component system Pd(OAC)(2)-1,3bis(alkyl)imidazolinium chlorides (2a-f) and CS2CO3 catalyses quantitatively the Suzuki crosscoupling of deactivated aryl chlorides. Copyright (C) 2004 John Wiley Sons, Ltd.
Palladium-catalyzed Suzuki-Miyaura reaction using saturated N-heterocarbene ligands
(Springer, 2004) Özdemir, I; Çetinkaya, B; Demir, S; Gürbüz, N
The incorporation of saturated N-heterocyclic carbenes into palladium pre-catalysts give high catalyst activity in the Suzuki coupling of deactivated aryl chloride substrates. [GRS] The complexes were generated in the presence of Pd(OAc)(2) by in situ deprotonation of bis(imidazolinium) bromides LHX (3) which were characterized by conventional spectroscopic methods and elemental analyses.
Suzuki reaction of aryl chlorides using saturated N-heterocarbene ligands
(John Wiley & Sons Inc, 2005) Özdemir, I; Yasar, S; Demir, S; Çetinkaya, B
From readily available starting materials, six 1,3-dialkly-imidazolinium bromides (2a-f) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. The incorporation of saturated N-heterocyclic carbenes into palladium precatalysts gives high catalyst activity in the Suzuki coupling of deactivated aryl chloride substrates in aqueous media. The complexes were generated in the presence of Pd(OAC)(2) by in situ deprotonation of 2a-f. (c) 2005 Wiley Periodicals, Inc.
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.
Synthesis of novel 1-alkylimidazoline and 1-alkylbenzimidazole palladium(II) complexes as efficient catalysts for Heck and Suzuki reactions involving arylchlorides
(Elsevier, 2004) Özdemir, I; Çetinkaya, B; Demir, S
Six palladium(II) complexes of the type [PdCl2(PR3)L], {PR3 = PPh3 or PPhMe2; L = 1-alkyl-2-imidazoline(1) or 1-alkylbenzimidazole(2)} have been prepared by reactions of [PdCl2(PR3)](2). The complexes were characterized by conventional spectroscopic methods and elemental analyses. The incorporation of N-coordinated imidazoline and benzimidazole complexes of palladium(II) gave high catalytic activity in the Suzuki coupling and Heck reaction of aryl bromides and deactivated aryl chloride substrates. (C) 2003 Elsevier B.V. All rights reserved.
Synthesis of novel palladium-carbene complexes as efficient catalysts for amination of aryl chlorides in ionic liquid
(Elsevier, 2004) Özdemir, I; Demir, S; Gök, Y; Çetinkaya, E; Çetinkaya, B
The synthesis and characterization of [PdCl2(N-heterocyclic carbene)(2)] (2, 3), an air and moisture-stable complexes are reported. Amination of aryl halides in 1-methy-3-butyl-imidazolidinium tetrafluoroborate in the presence of palladium-carbene complexes as catalysts are described. Aryl chlorides undergo smooth nucleophilic substitution reactions with primary amines in ionic liquid to afford the corresponding arylamines in excellent yields under mild conditions. (C) 2004 Elsevier B.V. All rights reserved.
Synthesis of novel rhodium-carbene complexes as efficient catalysts for addition of phenylboronic acid to aldehydes
(Elsevier Science Bv, 2004) Özdemir, I; Demir, S; Çetinkaya, B
Rhodium(I)-carbene complexes with 1,3-dialkylimidazolidin-2-ylidine ligand were prepared and characterized by conventional spectroscopic methods and elemental analyses. The rhodium-carbene complexes RhCl(COD)(1,3-dialkyl-imidazolinylidene), 2a-d, are an active catalyst for addition of phenylboronic acid to aldehydes. (C) 2004 Elsevier B.V. All rights reserved.
Synthesis, structure and spectroscopic characterization of 1,2-bis-(2,4,6-trimethylbenzylideneamino) ethanedichloropalladium(II)
(Taylor & Francis Ltd, 2006) Arici, C; Ülkü, D; Özdemir, I; Demir, S; Çetinkaya, B
The structure of 1,2-bis(2,4,6-trimethylbenzylideneamino)ethanedichloropalladium(II) was determined by X-ray diffraction methods. The structure derived from NMR and IR spectra and elemental analysis is consistent with it. The complex is orthorhombic, space group Pcab, with a = 14.8662(12), b = 15.0861(13), c = 20.6255(14) angstrom, V = 4625.7(6) angstrom(3) and Z = 8. In the lattice, there exists a weak C-H center dot center dot center dot Cl hydrogen bond.
Use of bis(benzimidazolium) -: palladium system as a convenient catalyst for Heck and Suzuki coupling reactions of aryl bromides and chlorides
(Wiley, 2006) Demir, S; Özdemir, I; Çetinkaya, B
Six new, sterically demanding bis(benzimidazolium) salts (2a-f) as NHC precursors have been synthesized and characterized. These salts, in combination with palladium acetate, provide active catalysts for the cross-coupling of aryl chlorides and bromides under mild conditions in aqueous media. Copyright (c) 2006 John Wiley & Sons, Ltd.
Use of tetrahydropyridinium salts for highly efficient palladium-catalyzed cross-coupling reactions of aryl bromides and chlorides
(Pergamon-Elsevier Science Ltd, 2005) Özdemir, I; Demir, S; Çetinkaya, B
New, sterically demanding 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (2) as NHC precursors have been synthesized and characterized. These salts, in combination with palladium acetate, provided active catalysts for the cross-coupling of aryl chlorides and bromides under mild conditions. The catalytic system was applied to the Heck, Suzuki and benzaldehyde (Kumada) coupling reactions. Catalyst activity was found to be influenced by the presence of a methoxy group on the ring of the p-position of benzyl substituent of the ligand precursor. (c) 2005 Elsevier Ltd. All rights reserved.

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