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Öğe 1,4,5,6-tetrahydropyrimidinium halides ligands for Suzuki-Miyaura cross-coupling of unactivated aryl chlorides(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 Cs2CO 3 catalyses quantitatively the Suzuki cross-coupling of deactivated aryl chloride.Öğe Benzimidazole, benzothiazole and benzoxazole ruthenium(II) complexes; catalytic synthesis of 2,3-dimethylfuran(Wiley-VCH Verlag, 2000) Çetinkaya B.; Özdemir I.; Bruneau C.; Dixneuf P.H.Fourteen ruthenium(II) complexes of the type [RuCl2(?6-arene)L], (arene = 1,4-MeC6H4Pr(i) or C6Me6; L = benzimidazole derivative in which the NH group is substituted by N-alkyl or isoelectronic O or S atoms) have been prepared by cleavage of [RuCl2(?6-arene)]2 with the N-heterocycle L. Their spectroscopic and electrochemical properties are described. The effect of the nature of the benzazole (L) on the catalytic activity of these complexes for the intramolecular cyclization of (Z)-3-methylpent-2-en-4-yn-1- ol into 2,3-dimethylfuran has also been studied; the benzimidazole complexes were found to be the most active.Öğe Dichloride[1-(2,4,6-trimethylbenzyl)-3-(biphenyl-2-ylmethyl) -imidazolidin-2-ylidine (?6-hexamethylbenzene)]ruthenium(2006) Arslan H.; Van Derveer D.; Özdemir I.; Yaşar S.; Çetinkaya B.The single crystal X-ray structure of the imidazolidin ruthenium complex, C38H46N2Cl2Ru, was determined. The complex is an orthorhombic space group Pbca with a = 17.3586(32) Å, b = 14.4447(27) Å, c = 27.4325(52) Å, and V = 6878.466(4) Å3 with Z = 8 for Dcalc = 1.357 g/cm3. It exhibits the expected 3-legged piano stool geometry. There is one coordination bond of the ruthenium atom with the electrons of the ?6-hexamethylbenzene, 2 symmetrical Ru-Cl bonds, and one Ru-C bond involving the imidazole ring. The coordination around the ruthenium atom is 4-fold, which in this is case is pseudo-tetrahedral. © TÜBİTAK.Öğe In situ preparation of palladium / N-heterocyclic carbene complexes and use for Suzuki reaction(HeteroCorporation, 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.Öğe Polyimides from a novel monomer 3,6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a catalytic application(Springer New York LLC, 2004) Seckin T.; Koytepe S.; Ozdemir I.; Giirbiiz N.; Çetinkaya B.Tricyclic heteroaraomatic dye-based monomer containing NMe2 units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl2 (p-cymene)]2 and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-e/5(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192-278 °C, and the 10% weight loss temperatures were above 503-635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-l-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC). © 2004 Springer Science+Business Media, Inc.Öğe Surface modification of inorganic oxide particles with a carbene complex of palladium: A recyclable catalyst for the Suzuki reaction(Springer New York LLC, 2004) Gürbüz N.; Özdemir I.; Seçkin T.; Çetinkaya B.The reaction of 1-(2,4,6-trimethylbenzyl)-3-(propyltriethoxysilane) imidazolidinium chloride, with the Pd(OAc)2 complex proceeded smoothly in DMSO to give the bis[1-(2,4,6-trimethylbenzyl)-3- (propyltriethoxysilane)imidazolidin-2-ylidene]dichloropalladium(II) complex that was grafted onto the surface of amorphous silica. The effects of various factors, such as reaction temperature and time, on the grafting efficiency was evaluated. Inorganic oxide particles that were modified with a carbene complex of palladium(II) were tested for catalytic activity in the Suzuki coupling reaction between phenylboronic acid and several aryl halides © 2004 Plenum Publishing Corporation.Öğe Synthesis of Tetraaminoalkenes containing the Reduced Pyrimidine Skeleton and the X-ray Molecular Structure of 1,1?-Ethylene-3,3?-dibenzylbi(hexahydropyrimidin-2-ylidene)(1996) Alici B.; Çetinkaya E.; Çetinkaya B.; Ülkü D.; Tahir M.N.Deprotonation of a 1,1?-bridged bis(1,3-dialkyl-1,4,5,6-tetrahydropyrimidinium) diiodide with NaH gives in high yield a tetraaminoalkene 4, whereas the corresponding non-bridged tetrahydropyrimidinium iodide reacts with NaH only in the presence of KOBut; the title bridged tetraaminoalkene 4f was structurally characterized by single-crystal X-ray diffraction.
