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Bioactive NHC-derived palladium complexes: synthesis, catalytic activity for the Suzuki-Miyaura coupling of aryl chlorides and bromides and their antibacterial activities
(Taylor & Francis Ltd, 2019) Boubakri, Lamia; Al-Ayed, Abdullah S.; Mansour, L.; Abutaha, Nael; Harrath, Abdel Halim; Ozdemir, I; Yasar, S.
Pd(II)-bis(NHC) complexes (where NHC = N-heterocyclic carbene) bearing asymmetrically and symmetrically substituted NHC-ligand have been synthesized via deprotonation of 5,6-dimethylbenzimidazolium salts. The NHC precursors have been achieved via the two step N-alkylation of 5,6-dimethylbenzimidazole. The resultant salts were deprotonated with PdCl2 and K2CO3 in dry THF for 2(a-e). The obtained complexes were identified and characterized by H-1 and C-13 NMR, FT-IR, DART-TOF mass spectrometry and elemental analysis. These new Pd(II)-bis(NHC) complexes were applied as catalyst precursors for Suzuki-Miyaura cross-coupling reactions of aryl bromides and chlorides with phenylboronic acid to afford the corresponding products in good yields. This catalytic reaction was evaluated in the presence of KOtBu/toluene. The antibacterial activities of 2(a-e) were investigated against Gram (+)/(-) bacteria using the agar dilution procedure. The antibacterial activities of 2 vary with the nature of the ligands; MIC values of 2(a-e) were determined.
cis-1,1'-Dimethyl-3,3'-diphenyl-2,2'-biimidazolidinylidene
(Munksgaard Int Publ Ltd, 1997) Ulku, D; Tahir, MN; Cetinkaya, B; Ozdemir, I
The structure of the air-sensitive title compound consists of C20H24N4 molecules connected through a hydrogen bond. Neither the molecule as a whole nor the individual five-membered rings have a planar geometry. The dihedral angle between the best planes of the two phenyl rings is 50.87 (14)degrees. Weak intermolecular hydrogen bonding is observed between a C atom and an imidazolidine N atom.
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.
Protective effect of melatonin on experimental spinal cord ischemia
(Springernature, 2003) Erten, SF; Kocak, A; Ozdemir, I; Aydemir, S; Colak, A; Reeder, BS
Study design: Experimental animal model to assess ischemic spinal cord injury following occlusion of the thoraco-abdominal aorta. Objectives: To measure whether melatonin administered to rabbits before and after occlusion exerts an effect on the repair of ischemia-reperfusion (IR) injury. Setting: Medical Biology Laboratory, Inonu University, Malatya, Turkey. Methods: Rabbits were divided into three IR treatment groups and one sham-operated (ShOp) control group. The three treatment groups had their infrarenal aorta temporarily occluded for 25 min, while the ShOp group had laparotomy without aortic occlusion. Melatonin was administered either 10 min before aortic occlusion or 10 min after the clamp was removed. Physiologic saline was administered to the control animals. After treatment, the animals were euthanized and lumbosacral spinal cord tissue was removed for the determination of relevant enzyme activities. Results: Malondialdehyde levels, indicating the extent of lipid peroxidation, were found to be significantly increased in the nonmelatonin treated (IR) group when compared to the ShOp group. Melatonin, whether given to pre- or post occlusion groups, suppressed malondialdehyde levels below that of the ShOp group. Catalase (CAT) and glutathione peroxidase (GSH-Px) enzyme activities were increased in the IR group compared to the ShOp group. Melatonin given preocclusion resulted in a significant decrease in both CAT and GSH-Px enzyme levels. The superoxide dismutase ( SOD) enzyme activity was decreased in the ischemia-reperfusion treatment group. However, the melatonin treatment increased SOD enzyme activity to levels approximating that of the ShOp group. Conclusion: To our knowledge, this is the first study that shows the effects of melatonin administered both pre- and postischemia on induced oxidative damage to injured spinal cords. Our data also expands on reports that melatonin administration may significantly reduce the incidence of spinal cord injury following temporary aortic occlusion.
Ruthenium-carbene catalysts for the synthesis of 2,3-dimethylfuran
(Elsevier Science Bv, 1997) Cetinkaya, B; Ozdemir, I; Bruneau, C; Dixneuf, PH
A variety of neutral arene-ruthenium-carbenes of type (arene)RuCl2(=C(NR)CH(2)CH(2)NR) have been used for the catalytic transformation of (Z)-3-methylpent-2-en-4-yn-l-ol into 2,3-dimethylfuran. The catalytic reaction takes place at 80 degrees C with mononuclear complexes III-V to afford the furan in similar to 90% yield. The binuclear catalysts VIa and VIIa having a linked bis-carbene bridge operate at room temperature to initiate an exothermic reaction offering 90-97% of furan.
Substituted N-heterocyclic carbene PEPPSI-type palladium complexes with different N-coordinated ligands: Involvement in the direct C-H bond activation of heteroarenes derivatives with aryl bromide and their antimicrobial, anti-inflammatory and antioxidant activities
(Elsevier Science Sa, 2022) Slimani, I; Boubakri, L.; Ozdemir, N.; Mansour, L.; Ozdemir, I; Gurbuz, N.; Yasar, S.
In this study new benzimidazolium salt as N-heterocyclic carbene precursors and their related new PEPPSI-Pd (II)-N-heterocyclic carbene (NHC) complexes 3a-e were prepared and caracterized. The structures of all compounds have been characterized by H-1 NMR, C-13 NMR, and IR spectroscopy, as well as elemental analysis techniques and Direct analysis in real time (DART)-time-of-flight mass spectrometry (TOF-MS), which support the proposed structures. Further confirmations of structural details were provided by a single-crystal X-ray. A single crystal of PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complex 3c shows that the coordination geometry around Pd slightly distorted square-planar geometry. Next, the PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complexes 3a-e were used as catalysts in the direct C-5-arylation of 2-acetyl furan and 2-acetylthiophene with various aryl bromides. These complexes exhibited moderate to high catalytic activities and gave C-H activation selectively at the C-5-position. Further, PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complexes 3a-e have been evaluated for their potential antibacterial properties against a panel of bacterial strains namely, Micrococcus luteus, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus, candida albican and pseudomonas aeruginosa. In addition; these new PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complexes 3a-e were investigated for anti-oxidant activities by super oxide radical; DPPH (2,2-Diphenyl-1-picrylhydrazyl); and hydroxyl radical scavenging assays; in which most of them displayed significant antioxidant activities. Furthermore; PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complexes 3a-e were evaluated for anti-inflammatory activity by indirect haemolytic and lipoxygenase inhibition assays and revealed good activity.
Syntheses and properties of metal containing polyimides based on the gold carbene complex
(Springer, 2003) Seckin, T; Koytepe, S; Ozdemir, I; Çetinkaya, B
A novel gold carbene complex, bis(1,3-di-p-dimethylaminobenzylimidazolidinylidene) gold(I), was synthesized and polymerized to polyimides in a one-step method with various aromatic dianhyrides. The gold-coordinated polyimides are characterized by IR and NMR (H-1, C-13) spectroscopy. The materials have inherent viscosities that range from 1.88 to 2.39 dl/g and show excellent solubility in N-methylpyrrolidone and N,N-dimethylacetamide. The glass transition temperatures of the coordinated polyimides range from 203-265degreesC and a 5% weight loss in air is observed from 535-578degreesC. The polymers form dark yellow, tough films that are transparent above 365 nm. The effect of different flexible units on the properties of the polyimides is discussed.
Synthesis and catalytic properties of arene complexes of ruthenium(II) prepared from Si, Zr, Ti and Al alkoxides by the sol-gel process
(Royal Soc Chemistry, 1998) Cetinkaya, B; Seckin, T; Ozdemir, I; Alici, B
Methods of synthesizing materials for catalysis were developed by synthesizing eta-arene complexes of ruthenium(II) coordinated to vinylpyridine that was followed by sol-gel polymerization with 3-methacryloxypropyltriethoxysilane. To enforce sufficient catalytic properties, a series of hybrid materials from Si, Zr, Ti and Al alkoxides were prepared by co-condensation. The hydrolysis and polycondensation of materials were performed at different experimental conditions. The monomeric compounds were identified and catalytic activities were tested for cyclization of (Z)-3-methylpent-2-en-4-yn-1-ol to 2,3-dimethylfuran.
Synthesis and catalytic properties of N-functionalized carbene complexes of rhodium(I) and ruthenium(II)
(Elsevier Science Sa, 1997) Cetinkaya, B; Ozdemir, I; Dixneuf, PH
Imidazolidin-2-ylidene derivatives of rhodium(I) and ruthenium(II), having 2-methoxyethyl substituent on the N-atom, [Rh(L)Cl(PPh3)(2)], [Rh(L)Cl(COD)] or [Ru(L)Cl-2(arene)] (L-1 = CN(Me)CH2CH2NCH2CH2OMe and L-2 = CN(CH2CH2OMe)CH2CH2NCH2CH2OMe) have been prepared by treatment of [RhCl(PPh3)(3)], [RhCl(COD)](2) or [RuCl2(arene)](2) with the N-functionalized electron-rich olefins L-1 = L-1 or L-2 = L-2. All of the new carbene rhodium(I) or ruthenium(II) complexes have proved to be effective catalysts for the cyclopropanation reactions of diazoalkane derivatives with styrene and the rhodium(I) precursors lead to the highest catalytic activity.
Synthesis and characterization of N-substituted 1,4,5,6-tetrahydropyrimidine containing functional polymers as SO2 and CO2 sorbents
(John Wiley & Sons Inc, 1997) Seckin, T; Alici, B; Cetinkaya, E; Ozdemir, I
Novel vinyl monomers containing 1,4,5,6-tetrahydropyrimidine were prepared by the reaction of N-substituted-1,3-diaminopropane with N,N-dimethyl-formamide dimethylacetal, which gave l-alkyl or aryl substituted 1,4,5,6-tetrahydropyrimidines, Alkylation of the tetrahydropyrimidine derivatives by chloromethylstyrene produces the N-methyl-N'-vinyl benzyl-1,4,5,6-tetrahydropyrimidinium chloride in high yields, These monomers were readily polymerized in dimethylformamide by AIBN at 80 degrees C. Homopolymers and soluble linear copolymers were prepared and copolymerization parameters were rationalized. Further, insoluble terpolymers prepared from these monomers, styrene and divinylbenzene were tested for the sorption of the weakly acidic gases gave excellent results. (C) 1997 John Wiley & Sons, Inc.
Synthesis and radical polymerization of novel vinyl monomers having the imidazoline and pyrimidine moiety
(Springer Verlag, 1996) Seckin, T; Alici, R; Cetinkaya, E; Ozdemir, I
Alkylation of the methylene bridged tetrahydropyrimidine derivatives by chloromethylstyrene produces the bridged bis(4-vinylbenzyl)-1,4,5,6,-tetrahydropyrimidinium salts in high yields. Similar procedures are used to prepare 2-imidazolinium derivatives. The quaternary salts which support functional side groups of potential biomedical interest are characterized by means of spectroscopic methods. These monomers are readily polymerized free radically in solution of dimethyl formamide at moderate temperatures. The soluble and insoluble polymers containing 2-imidazolinium and 1,4,5,6-tetrahydropyrimidinium salts were found to exhibit antibacterial activites against Escherichia coli.
Synthesis of cis- and trans-dichloro(dimethylphenylphosphine) x-(1-methyl-1,4,5,6-tetrahydropyrimidine)platinum(II) and their spectral and structural characterization
(Elsevier Science Sa, 1998) Cetinkaya, B; Ozdemir, I; Tahir, MN; Ulku, D
Interaction of [{Pt(mu-Cl)Cl(PMe2Ph)}(2)] with 1-methyl-1,4,5,6-tetrahydropyrimidine, L (R = Me), in boiling toluene produced a mixture of cis- and trans- isomers of [PtCl2(PMe2Ph){N = CH(Me)CH2CH2CH2}] trans-complex 2 isomerizes to give thermody-namically more stable corresponding cis-complex 1 in boiling ethanol. Spectroscopic and X-ray diffraction data permit generalizations about cis- and trans- isomeric pairs to be made. In addition, the trans influence of the ligand L is reliably assessed. (C) 1998 Elsevier Science S.A. All rights reserved.
Synthesis, characterization, biological determination and catalytic evaluation of ruthenium(ii) complexes bearing benzimidazole-based NHC ligands in transfer hydrogenation catalysis
(Royal Soc Chemistry, 2020) Slimani, Ichraf; Chakchouk-Mtibaa, A.; Mansour, L.; Mellouli, L.; Ozdemir, I; Gurbuzd, Nevin; Hamdi, Naceur
A new series of ruthenium(ii) N-heterocyclic carbene complexes has been synthesized via transmetalation. These complexes are easily handled in very good yields via synthesis of silver-NHC complexes and subsequent reaction with [RuCl2(p-cymene)](2) in dichloromethane (DCM) under argon atmosphere. The new ruthenium(ii)-NHC complexes were applied to transfer hydrogenation of ketone derivatives using 2-propanol as a hydrogen source and KOH as a co-catalyst. The results show that the corresponding alcohols could be obtained in good yield with high catalyst activity (up to 76%) under mild conditions. All new compounds were characterized by spectroscopic and analytical methods. The antibacterial activities of the corresponding ruthenium(ii)-NHC complexes 4a-i were tested against positive and negative bacteria using the agar dilution procedure and their IC50 values have been determined. A cytotoxicity study of the ruthenium(ii)-NHC complexes 4 was performed against the two human cancer cell lines MDA-MB-231 and MCF-7. In addition, the scavenging activity of the synthesized complexes for the DPPH radical was also determined.
Synthesis, spectroscopic properties and biological activity of new Cu(I) N-Heterocyclic carbene complexes
(Elsevier, 2019) Touj, N.; Chakchouk-Mtibaa, A.; Mansour, L.; Harrath, A. H.; Al-Tamimi, J.; Mellouli, L.; Ozdemir, I
New benzimidazolium salts (2) and their copper N-heterocyclic carbene complexes (3 4) were designed, synthesized and structurally characterized by NMR (H-1 and C-13), IR, HRMS and elemental analysis. All obtained complexes especially compounds 3d and 3e, presented significant inhibitory activity against the tested food-borne pathogens and clinical microorganisms. The compound 3b presents against S. aureus a MIC value of 0.0195 mg/ml quite similar to that of ampicillin (0.0195 mg/ml) used as standard. Compounds 3a and 3b, from a concentration of 0.5 mg/ml, present an identical scavenging activity to that of the two used controls butylated hydroxytoluene (BHT) and gallic acid (GA). Concerning acetylcholinesterase inhibition activity (AChEI), compound 3e presents an interesting AChEI activity with 32.80% of inhibition. (C) 2018 Published by Elsevier B.V.
Synthesis, structural characterization of silver(I)-NHC complexes and their antimicrobial, antioxidant and antitumor activities
(Elsevier, 2020) Slimani, Ichraf; Mansour, Lamjed; Abutaha, Nael; Harrath, Abdel Halim; Al-Tamimi, Jameel; Gurbuz, Nevin; Ozdemir, I
To prepare a novel series of silver (I) complexes, the interaction of benzimidazolium salts having their two nitrogen atoms substituted by bulky groups with Ag2O in DMF has been carried out. Their structures were characterized by elemental analyses, H-1 NMR, C-13 NMR and IR spectroscopy techniques. Further, the antibacterial properties of both the salts and their silver(I)-NHC complexes were tested against positive and negative bacteria using the agar dilution procedure. The results show that silver complexes are effective against Salmonella Typhimurium, Listeria monocytogenes, and Micrococcus luteus with moderate to high activity, and their minimum inhibitory concentrations ranging from 0.0024 to 1.25 mg/ml. Moreover, the antioxidant activity determination of these compounds were studied with the DPPH, and compared with (gallic acid GAand butylatedhydroxytoluene BHT ). They exhibited significant antioxidant activities. In addition, the of benzimidazoles salts 2a-j and silver-NHC complexes 3a-j were screened for their antitumor activity. The highest antitumor activity was observed for 3e and 3d Complexes and they exhibited IC50 values 6.85 mu g/mL against MCF-7 and 10.75 mu g/mL against T47D, respectively. (C) 2019 The Authors. Published by Elsevier B.V. on behalf of King Saud University.

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