Senem Akkoç

Synthesis and characterization of 1-phenyl-3-alkylbenzimidazol-2-ylidene salts and their catalytic activities in the Heck and Suzuki cross-coupling reactions

The synthesis and characterization of 1-phenyl-3-alkyl-substituted carbene precursors that were prepared from 1-phenyl substituted benzimidazole and various alkyl halides are reported. The new benzimidazolium salts (1a–e) were characterized by 1H NMR, 13C NMR, FT-IR spectroscopic methods and elemental analyses. New in situ generated palladium-benzimidazolium complexes were tested for catalytic activity in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions.

Palladium catalyzed Mizoroki–Heck and Suzuki–Miyaura reactions using naphthalenomethyl-substituted imidazolidin-2-ylidene ligands in aqueous media

Naphthalenomethyl-substituted imidazolidinium salts (1a-g) were prepared and characterized by conventional spectroscopic methods, 1H NMR, 13C NMR, FTIR, and elemental analysis techniques. The in situ prepared three component systems naphthalenomethyl-substituted imidazolidinium salts, Pd(OAc)2, and K2CO3 catalyzed quantitatively the Mizoroki–Heck and Suzuki–Miyaura coupling of aryl halides under mild conditions in aqueous media.

N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd-NHC complexes: synthesis, characterization and catalytic activity in carbon-carbon bond-forming reactions.

Summary A series of novel benzimidazolium salts (1–4) and their pyridine enhanced precatalyst preparation stabilization and initiation (PEPPSI) themed palladium N-heterocyclic carbene complexes [PdCl2(NHC)(Py)] (5–8), where NHC = 1-(N-methylphthalimide)-3-alkylbenzimidazolin-2-ylidene and Py = 3-chloropyridine, were synthesized and characterized by means of 1H and 13C{1H} NMR, UV–vis (for 5–8), ESI-FTICR-MS (for 2, 4, 6–8) and FTIR spectroscopic methods and elemental analysis. The synthesized compounds were tested in Suzuki–Miyaura cross-coupling (for 1–8) and arylation (for 5–8) reactions. As catalysts, they demonstrated a highly efficient route for the formation of asymmetric biaryl compounds even though they were used in very low loading. For example, all compounds displayed good catalytic activity for the C–C bond formation of 4-tert-butylphenylboronic acid with 4-chlorotoluene.

In vitro antimicrobial studies of new benzimidazolium salts and silver N-heterocyclic carbene complexes

Abstract A series of new benzimidazolium salts (1a–g) were synthesized from the reaction of 1-(4-vinylbenzyl)benzimidazole with various alkyl halides. These salts were used to synthesize silver N-heterocyclic carbene (Ag-NHC) complexes (2a–f). The thirteen compounds were characterized by FT-IR, NMR (1H and 13C) spectroscopic methods and an elemental analysis technique. These selected candidates were tested for their in vitro antimicrobial activities. Antibacterial and antifungal results indicated that the new salts, and particularly their silver complexes, were found to be strongly effective against seven Gram (−) bacterial strains, three Gram (+) bacterial strains and one yeast (Candida albicans).

N-Heterocyclic carbene silver complexes: synthesis, characterization and in vitro antimicrobial studies

Six new 2-morpholinoethyl and 2-diethylaminoethyl substituted N-heterocyclic carbene (NHC) silver complexes (2a-f) were synthesized from the reaction 1-(2-morpholinoethyl)-3-napthalenomethlbenzimidazolium chloride (1a), 1-(2-morpholinoethyl)-3-(2-methylbenzyl)benzimidazolium chloride (1b), 1-(2-morpholinoethyl)-3-(2,3,5,6-tetramethylbenzyl)benzimidazolium chloride (1c), [1-(2-diethylaminoethyl)-3-(3-methylbenzyl)benzimidazolium chloride (1d), [1-(2-diethylaminoethyl)-3-(2,3,5,6-tetramethylbenzyl)benzimidazolium chloride (1e), [1-(N,N-diethylethane)-3-(2,3,4,5,6-pentamethylbenzyl)benzimidazolium chloride (1f) with silver oxide (Ag2O) in dichloromethane at room temperature. These silver complexes were characterized by means of 1H NMR, 13C NMR, FT-IR spectroscopy and elemental analysis techniques. Also, [1-(N,N-diethylethane)-3-(2,3,4,5,6-pentamethylbenzyl)benzimidazol-2-ylidene]chlorosilver(I) complex (2f) was characterized by means of LC-MS and Maldi-MS methods. All silver complexes (2a-f) were screened fo...

Benzimidazolium-based novel silver N-heterocyclic carbene complexes: synthesis, characterisation and in vitro antimicrobial activity

Abstract This study reports the synthesis, characterisation and antimicrobial activity of five novel silver N-heterocyclic carbene (Ag–NHC) complexes obtained by N-propylphthalimide and N-methyldioxane substituted benzimidazolium salts with silver oxide. The reactions were performed at room temperature for 24 h in the absence of light. The obtained complexes were identified and characterised by 1H and 13C NMR, FT-IR and elemental analysis techniques. The minimum inhibitory concentration (MIC) of the complexes was determined for E. coli, P. aeruginosa, E. faecalis, S. aureus, C. tropicalis and C. albicans in vitro through agar and broth dilution. The results indicated that these complexes exhibit antimicrobial activity. In particular, complex 3 presented the significant broad spectrum antimicrobial activity.

Antimicrobial Studies of N-Heterocyclic Carbene Silver Complexes Containing Benzimidazol-2-ylidene Ligand

Seven novel 4-vinylbenzyl substituted N-heterocyclic carbene (NHC) silver complexes were synthesized from different benzimidazolium salts and silver (I) oxide in dichloromethane at room temperature. These new 4-vinylbenzyl substituted NHC silver complexes were characterized by spectroscopic (NMR, IR) and elemental analysis techniques. Using the agar dilution procedure, the antimicrobial activities of these synthesized new compounds were investigated against Gram (

Chlorido[1-phenyl-3-(2,3,5,6-tetra-methyl-benz-yl)benzimidazol-2-yl-idene]silver(I).

In the title compound, [AgCl(C24H24N2)], the terminal phenyl and tetramethylbenzene rings [which form a dihedral angle of 87.92 (14)°] make dihedral angles of 59.59 (11) and 83.19 (12)° with respect to the central benzimidazole ring system. The Ag—C and Ag—Cl single-bond lengths are 2.087 (3) and 2.3267 (9) Å. The C—Ag—Cl bond angle is 172.84 (7)°. C—H⋯π interactions contribute to the stabilization of the crystal structure. A very weak π–π stacking interaction between adjacent tetramethylbenzene rings [centroid–centroid distance = 4.0610 (18) Å] is also observed.

Synthesis, characterization, and antimicrobial and catalytic activity of a new Schiff base and its metal(II) complexes

We presented the synthesis of a new Schiff base and its complexes properties with some transition metal ions in this study. (1-amino-2-thioxo-4-p-tolyl-1,2-dihydropyrimidin-5-yl)(p-tolyl)methanone was synthesized as the starting material, and (1-((2-hydroxynaphthalen-1-yl)methyleneamino)-2-thioxo-4-p-tolyl-1,2-dihydropyrimidin-5-yl)(p-tolyl)methanone (Hnafmmp) (1) and its Ni(II) (2), Pd(II) (3), Pt(II) (4), Cu(II) (5), Co(II) (6) complexes were prepared using above-mentioned starting material. The structures of these new compounds (ligand and its complexes) were characterized with UV–Vis, FTIR, LC–MS, 1H NMR, 13C NMR, magnetic susceptibility, conductivity measurement, X-ray powder diffraction method, and thermal analyses techniques. The 1H NMR chemical shifts of all complexes were calculated by using the gauge-invariant atomic orbital HF (3.21G) method in DMSO phases. All measured results were compared with the experimental data. The ligand and its complexes were also evaluated as antimicrobial agents against representative strains bacteria. Furthermore, we studied the catalytic activity of these compounds in Suzuki–Miyaura cross-coupling reaction in aqueous media.

Density functional theory study of a silver N-heterocyclic carbene complex

Geometry optimization was carried out by using the density functional theory method with B3LYP applying 6-31G* basis set by plotting the X-ray single crystal structure in the gas phase. Some solven...