Nevin Gürbüz

Synthesis and immobilization of N-heterocyclic carbene complexes of Ru(II): catalytic activity and recyclability for the furan formation

Abstract Synthesis, characterization and immobilization of ruthenium(II) complexes of the type [RuCl 2 L(η 6 -arene)] (L= , arene= p -cymene, 3 and arene=C 6 Me 6 , 4 ) and [RuCl 2 L] (L=η 1 -carbene-η 6 -arene bidentate ligand, ), 5 , morphologically different silicas by sol–gel method are described and their reactivity and recyclability in the furan formation were also reported.

Synthesis and Antimicrobial Activity of Novel Ag-N-Hetero-cyclic Carbene Complexes

A series of imidazolidinium ligand precursors are metallated with Ag2O to give silver(I) N-heterocyclic carbene complexes. All compounds were fully characterized by elemental analyses, 1H-NMR, 13C-NMR and IR spectroscopy techniques. All compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the fungi Candida albicans and Candida tropicalis. The new imidazolidin-2-ylidene silver complexes have been found to display effective antimicrobial activity against a series of bacteria and fungi.

Suzuki–Miyaura Reaction of Unactivated Aryl Chlorides Using Benzimidazol‐2‐Ylidene Ligands

Abstract Four functionalized bis(benzimidazolium) salts (2a–d) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle, and environmentally bengin process for palladium‐mediated Suzuki cross‐coupling was developed. The in situ prepared three‐component system Pd(OAc)2/bis(benzimidazolium) bromides (2a–d) and Cs2CO3 catalyzes quantitatively the Suzuki cross‐coupling of deactivated aryl chloride in aqueous media.

N-Heterocyclic carbene–palladium catalysts for the direct arylation of pyrrole derivatives with aryl chlorides

Summary New Pd–NHC complexes have been synthesized and employed for palladium-catalyzed direct arylation of pyrrole derivatives by using electron-deficient aryl chlorides as coupling partners. The desired coupling products were obtained in moderate to good yields by using 1 mol % of these air-stable palladium complexes. This is an advantage compared to the procedures employing air-sensitive phosphines, which have been previously shown to promote the coupling of aryl chlorides with heteroarenes.

Comparison of reproductive toxicity caused by cisplatin and novel platinum-N-heterocyclic carbene complex in male rats.

Cisplatin and other platinum complexes are important chemotherapeutic agents and useful in the treatment for several cancers such as prostate, ovarian and testis. However, severe side effects including reproductive toxicity of cisplatin and other platinum complex cause limitations in their clinical usage. In this context, we aimed to compare the damage in testis caused by cisplatin and a novel platinum-N-heterocyclic carbene complex (Pt-NHC). To this end, 35 Sprague-Dawley rats were divided randomly into five equal groups (n = 7 in each group). Cisplatin and Pt-NHC were intraperitoneally administered as a single dose of 5 mg/kg or 10 mg/kg, and the rats were then killed 10 days after this treatment. The testicular tissues and serum samples were taken from all rats for the determination of reproductive toxicity. The results showed that cisplatin and Pt-NHC caused toxicity on the reproductive system via increased oxidative and histological damage, decreased serum testosterone levels and negatively altered sperm characteristics in a dose-dependent manner (p < 0.05). At the same dose levels, cisplatin generally caused lower toxicity on the reproductive system compared with Pt-NHC. In conclusion, these results suggest that Pt-NHC has more toxic effects on the male reproductive system than cisplatin, and in terms of clinical usage, Pt-NHC may be unsafe compared with cisplatin.

Synthesis, characterization and catalytic activity of novel N-heterocyclic carbene-palladium complexes

The reaction of Pd(OAc)2 with 1-(benzhydryl)-3-(alkyl)benzimidazolium salts 1a-d yields trans-bis[1-(benzhydryl)-3-(alkyl)benzimidazolin-2-ylidene]dibromopalladium(II) complexes (2a-d) which were characterized by elemental analysis, NMR spectroscopy and the molecular structures of 2b, and 2d were determined by X-ray crystallography. The catalytic activity of PdBr2bis(benzimidazolin-2-ylidene) complexes 2a-d was evaluated in the direct arylation reaction of benzothiazole with bromobenzene derivatives.

Novel platinum-N-heterocyclic carbene complex is more cardiotoxic than cis-platin in rats

Cis-platin and other platinum complexes are important chemotherapeutic agents useful in the treatment of several cancers. However, therapeutic usage of cis-platin and other platinum complex are limited by their undesirable side effects including cardiotoxicity. In this context, we aimed to compare the damage caused in heart by cis-platin and novel platinum-N-heterocyclic carbene (Pt-NHC) complex. For this purpose, 35 Sprague-Dawley rats were divided randomly into five equal groups (n = 7 for each group). Cis-platin and novel Pt-NHC complex were intraperitoneally administered at a single dose of 5 mg/kg and 10 mg/kg and then sacrificed 10 days after this treatment. The heart tissues were taken from all rats for determination of oxidative and myocardial damage. Cis-platin and novel Pt-NHC complex caused oxidative and histological damage in the heart tissue in a dose-dependent manner (p < 0.05). On the other hand, at the same dose levels, cis-platin caused lower oxidative and histological damage in heart tissue compared to novel Pt-NHC complex. These results suggest that novel Pt-NHC complex is more cardiotoxic than cis-platin.

Palladium-Catalyzed Heck Coupling Reaction of Aryl Bromides in Aqueous Media Using Tetrahydropyrimidinium Salts as Carbene Ligands

An efficient and stereoselective catalytic system for the Heck cross coupling reaction using novel 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (1, LHX) and Pd(OAc)2 loading has been reported. The palladium complexes derived from the salts 1a-f prepared in situ exhibit good catalytic activity in the Heck coupling reaction of aryl bromides under mild conditions.

In‐situ Generated 1‐Alkylimidazoline‐palladium Catalyst for the Suzuki Cross‐coupling Reaction of Aryl Chlorides

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.

Polyimides from a Novel Monomer 3,6-Bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a Catalytic Application

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-bis(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-1-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).