Yazar "Mansour, Lamjed" seçeneğine göre listele

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    Amine-fnctionalized silver and gold N-heterocyclic carbene complexes: Synthesis, characterization and antitumor properties
    (Elsevier Science Sa, 2019) Kizrak, Umran; Ciftci, Osman; Ozdemir, Ilknur; Gurbuz, Nevin; Dusunceli, Serpil Demir; Kaloglu, Murat; Mansour, Lamjed
    Diisopropilamine-tethered benzimidazolium salts have been prepared as precursors for Ag(I)-NHC and Au(I)-NHC complexes. These NHC ligands were metallated with Ag2O on moderate conditions to give novel silver-NHC complexes. Gold-NHC complexes have been obtained by transmetalation using the silver-NHC precursor. The structures of all compounds were characterized by H-1 NMR, C-13 NMR, IR and elemental analysis techniques. The cytotoxic properties of the silver(I) and gold(I) complexes have been assessed in various human cancer lines, including cisplatin-sensitive and resistant cell. IC50 values of these four complexes were determined by the MTS based assay on three human cancer cell lines (SHSY5Y, HTC116 and HEP3B) and human healthy cell line (HF). These silver and gold N-heterocyclic carbene complexes have been highlighted metal-based cancer therapeutic agent with unique structures and functions. These strategies provide exciting opportunities for discovering new type metalodrug. (C) 2019 Elsevier B.V. All rights reserved.
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    Anticancer, antimicrobial and antiparasitical activities of copper(I) complexes based on N-heterocyclic carbene (NHC) ligands bearing aryl substituents
    (Taylor & Francis Ltd, 2020) Touj, Nedra; Al Nasr, Ibrahim S.; Koko, Waleed S.; Khan, Tariq A.; Ozdemir, Ismail; Yasar, Sedat; Mansour, Lamjed
    New benzimidazolium salts were synthesized as N-heterocyclic carbene precursors. These NHC precursors were metallated with Cu2O and CuI in acetone and water under reflux to give novel copper(I) complexes. The structures of these benzimidazolium salts and copper(I) complexes were characterized on the basis of elemental analysis, H-1 NMR, C-13 NMR, IR and LC-MS spectroscopic techniques. The (NHC)Cu(I) complexes 3-4 were tested against MCF7 and MDA-MB-231 cancer cells, Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans microorganisms, Leishmania major promastigotes and amastigotes, Toxoplasma gondii parasites and against Vero cell line in vitro. The synthesized copper NHC carbene complex 4b (1,3-bis(2,3,4,5,6-pentamdthylbenzyl)-2,3-dihydro-1H-benzo[d]imidazol-2-yl)copper(I) chloride) was the most active against MCF7 cancer cells (half growth Inhibition Concentrations (IC50) = 0.3 mu g mL(-1)), as well as the most potent antimicrobial against E. coli (inhibition zone (IZ) = 23.3 mm), MRSA (IZ = 25.5 mm) and C. albicans (IZ = 28.5 mm) besides its antileishmanial activities against L. major promastigotes and amastigotes (IC50 < 0.04 mu g mL(-1)). Compound 4c (1,3-bis(4-(tert-butyl)benzyl)-2,3-dihydro-1H-benzo[d]imida-zol-2-yl)copper(II) bromide) is the most potent anticancer against MDA-MB-231 cancer cells IC50 = 0.4 mu g mL(-1)). Compound 4e (5,6-dimethyl-1,3-bis(2,4,6-trimethylbenzyl)-2,3-dihydro-1H-benzo[d]imidazol-2-yl)copper(I) chloride) is the best suitable antitoxoplasmal drug candidate due to its SI of 16.5. These candidates need further study to identify mode of action and drug standardization.
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    Bridged NHC-Pd(II) complexes: Synthesis, DFT calculations, molecular docking, and investigation of catalytic and biological activities
    (Elsevier Science Sa, 2024) Firat, Tuba; Bugday, Nesrin; Yasar, Seyma; Boulebd, Houssem; Mansour, Lamjed; Koko, Waleed S.; Hamdi, Naceur
    Six palladium(II) ( 3a -f ) complexes of the type [Pd 2 ( mu-Cl) 2 (NHC)] were prepared by transmetallation of the corresponding Ag-NHC and [PdCl 2 (CH 3 CN) 2 ] complexes, and their structures were successfully characterised by 1 H NMR, 13 C NMR, HRMS, FTIR and elemental analysis. Density functional theory (DFT) calculations were also realised for the complexes. The prepared complexes were assessed for their catalytic activity in the C -H arylation of 2-isobuthylthiazole as well as for their biological activities. As results, these complexes were found to be potent catalysts in the creation of C5-arylated 2-isobuthylthiazole derivatives via C -H bond activation reaction. Furthermore, biological activity analysis revealed that complex 3a exhibits high cytotoxicity towards both human colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) with IC 50 values of 4.2 and 9.3 mu MmL -1 , respectively. Complex 3b also showed antioxidant activity comparable to that of BHT through DPPH and ABTS assays. Both complexes 3d and 3f also showed significant inhibitory activity towards the AChE enzyme with IC 50 values of 5.06 and 2.52 mu MmL -1 , respectively. Finally, all complexes showed excellent antiparasitic activity, with 3b exhibiting strong antileishmanial activity against both L. major promastigotes and amastigotes. The interaction between the most cytotoxic complexes and DNA, envisaged as a potential mechanism of toxicity, was explored by means of docking studies. In summary, these prepared complexes have the potential to serve as potent catalysts for the synthesis of arylated 2-isobutylthiazole and biologically active agents, paving the way for numerous prospects in the fields of medicinal chemistry and organic synthesis.
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    Efficient in situ N-heterocyclic carbene palladium(ii) generated from Pd(OAc)2 catalysts for carbonylative Suzuki coupling reactions of arylboronic acids with 2-bromopyridine under inert conditions leading to unsymmetrical arylpyridine ketones: synthesis, characterization and cytotoxic activities
    (Royal Soc Chemistry, 2018) Touj, Nedra; Al-Ayed, Abdullah S.; Sauthier, Mathieu; Mansour, Lamjed; Harrath, Abdel Halim; Al-Tamimi, Jamil; Ozdemir, Ismail
    N,N-Substituted benzimidazole salts were successfully synthesized and characterized by H-1-NMR, C-13 {H-1} NMR and IR techniques, which support the proposed structures. Catalysts generated in situ were efficiently used for the carbonylative cross-coupling reaction of 2 bromopyridine with various boronic acids. The reaction was carried out in THF at 110 degrees C in the presence of K2CO3 under inert conditions and yields unsymmetrical arylpyridine ketones. All N,N-substituted benzimidazole salts 2a-i and 4a-i studied in this work were screened for their cytotoxic activities against human cancer cell lines such us MDA-MB-231, MCF-7 and T47D. The N,N-substituted benzimidazoles 2e and 2f exhibited the most cytotoxic effect with promising cytotoxic activity with IC50 values of 4.45 g mL(-1) against MDA-MB-231 and 4.85 g mL(-1) against MCF7 respectively.
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    An efficient palladium catalyzed mizoroki-heck cross-coupling in water: synthesis, characterization and catalytic activities
    (Pergamon-Elsevier Science Ltd, 2024) Bensalah, Donia; Mansour, Lamjed; Sauthier, Mathieu; Gurbuz, Nevin; Ozdemir, Ismail; Gatri, Rafik; Hamdi, Naceur
    A series of new palladium complexes known as PEPPSI-type complexes 3 were successfully synthesized by reacting benzimidazolium salts 2a -e , potassium carbonate (K 2 CO 3 ), and palladium chloride (PdCl 2 ) in pyridine for 16 h at 80 degrees C. Both the benzimidazolium salts 2a -e and the resulting complexes 3 were characterized through spectroscopic data and elemental analysis. The Mizoroki-Heck coupling reaction, catalyzed by the homogeneous Pd, was effectively carried out in water without the need for any additional substances under aerobic conditions. The optimization of various key reaction parameters was performed to enhance the yield of the desired cross coupling product. The catalytic performance of these complexes in a catalytic system containing palladium complexes 3a , Et 3 N, and H 2 O was evaluated in the Mizoroki-Heck coupling reaction. The PEPPSI-type palladium complex 3a /Et 3 N/H 2 O/98 degrees C catalyst system exhibited high activity, with a turnover frequency (TOF) ranging from 12 to 14 /hour towards achieving the excellent yield of the Mizoroki-Heck coupling products for a wide range of electron withdrawing as well as electron donating aryl bromide and chlorides in shortest reaction time.
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    From synthesis to biological impact of palladium bis(benzimidazol-2-ylidene) complexes: Preparation, characterization, and antimicrobial and scavenging activity
    (De Gruyter Poland Sp Z O O, 2023) Amri, Nasser; Mukhrish, Yousef E.; Ozdemir, Ismail; Gurbuz, Nevin; Arfaoui, Youssef; Mansour, Lamjed; Gatri, Rafik
    Palladium-based complexes with the ligand N-heterocyclic carbene have long received attention as active catalysts for many catalytic reactions. Recently, the biological activities of these air- and moisture-stable complexes have also been investigated. In our work, bis(benzimidazol-2-ylidene)palladium complexes 3a-d were synthesized by reacting benzimidazolium salts 2a-d with PdCl2 under reflux in tetrahydrofuran for 24 h and analyzed by spectroscopy (FT-IR [Fourier transform infrared], H-1 NMR [proton nuclear magnetic resonance]) characterization, C-13 NMR [carbon-13 (C13) nuclear magnetic resonance]), and elemental analysis. The in vitro antibacterial and antifungal activities of these complexes were studied against Gram-positive and Gram-negative microorganisms, and two different fungi showed their remarkable biological potential. In addition, the analysis of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals using spectrophotometry showed that they are an antioxidant. The potent antibacterial and antioxidant activities of the synthetic complexes suggest that they are more effective antibacterial agents. Our study extends the biological relevance of palladium bis(benzimidazol-2-ylidene) complexes with antibacterial and antioxidant activities. Furthermore, the main goal of the docking simulation is to provide a detailed analysis of the interaction between the complex and the protein of interest.
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    Novel N-Heterocyclic Carbene Silver(I) Complexes: Synthesis, Structural Characterization, Antimicrobial and Cytotoxicity Potential Studies
    (Soc Brasileira Quimica, 2020) Slimani, Ichraf; Chakchouk-Mtibaa, Ahlem; Mellouli, Lotfi; Mansour, Lamjed; Ozdemir, Ismail; Gurbuz, Nevin; Hamdi, Naceur
    In this study, a series of unsymmetrical N,N-disubstituted benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) (2a-2j) and their Ag-I complexes. Their structures were characterized by elemental analyses, H-1 and C-13 nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy techniques. Further, both the salts and their silver(I)-NHC complexes have been evaluated for their potential antibacterial properties against a panel of bacterial strains namely, Micrococcus luteus, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus and Pseudomonas aeruginosa. 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 0.0034 to 1.26 mg mL(-1). In addition, the benzimidazoles salts 2a-2j and silver-NHC complexes 3a-3j were screened for their antitumor activity. Complex 3e exhibited the highest antitumor effect with half-maximal inhibitory concentration (IC50) value of 4.2 mu g mL(-1) against MCF-7.
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    Novel ruthenium(ii) N-heterocyclic carbene complexes: Synthesis, characterization, and evaluation of their biological activities
    (De Gruyter Poland Sp Z O O, 2023) Jawhari, Ahmed Hussain; Amri, Nasser; Mukhrish, Yousef E.; Gatri, Rafik; Ozdemir, Ismail; Gurbuz, Nevin; Mansour, Lamjed
    A series of ruthenium(ii) complexes with N-heterocyclic carbene (NHC) ligands of the general type (arene)(NHC)Ru(ii)X-2 (where X = halide) (3a-3d) were synthesized and characterized in order to compare their antibacterial activities with benzimidazolium salts 2. Our comparison revealed that ruthenium(ii) NHC complexes 3 were more active than benzimidazolium salts 2. Furthermore, the two complexes 3b and 3d had a potent inhibitory effect against acetylcholinesterase with an IC50 of 4.52 and 4.04 gmL(-1) and against tyrosinase with an IC50 of 20.77 and 25.84 gmL(-1), respectively. In addition, screening of benzimidazolium salts (2a-2d) and their ruthenium(ii) complexes (3a-3d) against colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) were studied. The obtained results revealed that complex 3a is the most active against vinblastines.
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    A Palladium Catalyst System for the Efficient Cross-Coupling Reaction of Aryl Bromides and Chlorides with Phenylboronic Acid: Synthesis and Biological Activity Evaluation
    (Mdpi Ag, 2017) Lamia, Boubakri; Chakchouk-Mtibaa, Ahlem; Hallouma, Bilel; Mansour, Lamjed; Mellouli, Lotfi; Ozdemir, Ismail; Yasar, Sedat
    New benzimidazolium salts 1a-c and their palladium bis-N-heterocyclic carbene complexes 2a-c and palladium PEPPSI-type complexes 3a-c were designed, synthesized and structurally characterized by NMR (H-1 and C-13), IR, DART-TOF mass spectrometry and elemental analysis. Then these complexes 2-3 were employed in the Suzuki-Miyaura cross-coupling reaction of substituted arenes with phenylboronic acid under mild conditions in toluene and DMF/H2O (1/1) to afford functionalized biaryl derivatives in good to excellent yields. The antibacterial activity of palladium bis-N-heterocyclic carbene complexes 2a-c and palladium PEPPSI-type complexes 3a-c was measured by disc diffusion method against Gram positive and Gram negative bacteria. Compounds 2a, 2c and 3a-c exhibited potential antibacterial activity against four bacterial species among the five used indicator cells. The product 2b inhibits the growth of the all five tested microorganisms. Moreover, the antioxidant activity determination of these complexes 2-3, using 2.2-diphenyl-1-picrylhydrazyl (DPPH) as a reagent, showed that compounds 2a-c and 3b possess DPPH antiradical activity. The higher antioxidant activity was obtained from the product 2b which has radical scavenging activity comparable to that of the two used positive controls (gallic acid GA and tutylatedhydroxytoluene BHT). Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 2b, 3a, and 3b exhibited moderate activity at 100 g/mL and product 2b is the most active.
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    Palladium(ii)/N-heterocyclic carbene (NHC) catalyzed direct C-H arylation of heteroarenes with different aryl bromides and chlorides
    (Royal Soc Chemistry, 2023) Bensalah, Donia; Mansour, Lamjed; Sauthier, Mathieu; Gurbuz, Nevin; Ozdemir, Ismail; Koko, Waleed S.; Gatri, Rafik
    The growing interest of industry in the field of bi(hetero)arene compounds motivated us to synthesize these compounds via a homogeneous catalytic route using Pd PEPPSI-type complexes through direct arylation. In this study, new Pd PEPPSI-type complexes bearing NHC spectator ligands were synthesized and characterized using spectroscopic techniques, such as (HNMR)-H-1, C-13 NMR, MS spectrometry, FTIR spectroscopy and elemental analysis (PEPPSI = pyridine enhanced precatalyst preparation stabilization and initiation). All the synthesized Pd(II) complexes were stable. The catalytic properties of these complexes were evaluated in the direct C-5 mono-arylation of furan, 2-acetylthiophene and N-methylpyrrole-2-carboxaldehyde derivatives with a wide variety of (hetero)aryl halides. This environmentally attractive procedure was found to be tolerant of a wide variety of functional groups on the aryl halides and good yields were obtained in the presence of 1 mol% catalyst loading at 150 degrees C for 2 hours. In addition, the conversions for substrates containing electron-withdrawing groups were higher than those for substituents containing electron-donating groups.
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    Pd-PEPPSI-type expanded ring N-heterocyclic carbene complexes: synthesis, characterization, and catalytic activity in Suzuki-Miyaura cross coupling
    (Taylor & Francis Ltd, 2024) Alnasser, Sarah; Touj, Nedra; Alomar, Suliman; Mansour, Lamjed; Sauthier, Mathieu; Gurbuz, Nevin; Ozdemir, Ismail
    In this work, we synthesized a series of six unsymmetrical benzimidazolium salts 2 and their pyridine-enhanced precatalyst preparation stabilization and initiation (PEPPSI)-themed palladium N-heterocyclic carbene complexes [PdCl2(NHC)(Py)]. All the products were isolated in satisfactory yields (75-85%). The synthesis of these novel palladium PEPPSI complexes involved in reacting NHC precursors with PdCl2 in pyridine at 60 degrees C in the presence of excess K2CO3. The structures of all compounds have been characterized by H-1 NMR, C-13 NMR, HRMS and IR spectroscopy, as well as elemental analysis techniques, which support the proposed structures. The catalytic activity of the six complexes was assessed in the Suzuki-Miyaura cross-coupling of phenylboronic acid and aryl halides. The reactions required only a low catalyst loading (0.1 mol%) and were carried out under mild aerobic conditions in a green, water-based solvent mixture.
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    Plausible PEPPSI catalysts for direct C-H functionalization of five-membered heterocyclic bioactive motifs: synthesis, spectral, X-ray crystallographic characterizations and catalytic activity
    (Royal Soc Chemistry, 2023) Bensalah, Donia; Mansour, Lamjed; Sauthier, Mathieu; Gurbuz, Nevin; Ozdemir, Ismail; Beji, Lotfi; Gatri, Rafik
    In this study, a series of benzimidazolium salts were synthesized as asymmetric N-heterocyclic carbene (NHC) precursors. Nine novel palladium complexes with the general formula [PdX2(NHC)(pyridine)] were synthesized using benzimidazolium salts in the PEPPSI (Pyridine Enhanced Precatalyst Preparation, Stabilization and Initiation) theme. All synthesized Pd(ii) complexes are stable. The synthesized compounds were thoroughly characterized by respective spectroscopic techniques, such as 1HNMR, 13C NMR, FTIR spectroscopy, X-ray crystallography and elemental analysis. The geometric structure of the palladium N-heterocyclic carbene has been optimized in the framework of density functional theory (DFT) using the B3LYP-D3 dispersion functional with LANL2DZ as a basis set. The on/off mechanism of pyridine assisted Pd-NHC complexes made them the best C-H functionalized catalysts for regioselective C-5 arylated products. Five membered heterocyclic compounds such as 2-acetyl furan, furfuryl acetate 2-acetylthiophene and N-methylpyrrole-2-carboxaldehyde were treated with numerous aryl bromides and arylchlorides under optimal catalytic reaction conditions. Interestingly, all the prepared catalysts possessed essential structural features that facilitated the formation of desired coupling products in quantitative yield with excellent selectivity. The arylation reaction of bromoacetophenone was highly catalytically active with only 1 mol% catalyst loading at 150 degrees C for 2 hours. To check the efficiency of the synthesized complexes, three different five member heterocyclic substrates (2-acetylfuran, 2-acetylthiophen, 2-propylthaizole) were tested with a number of aryl bromides bearing both electron-donating and electron-withdrawing groups on para position. The data in Tables 2-4. Indicated that electron-donating groups on the para position of aryl halide decreased the catalytic conversion while electron-withdrawing groups increased the catalytic conversion this was due to the high nucleophilicity of the electron-donating substituents. In this study, a series of benzimidazolium salts were synthesized as asymmetric N-heterocyclic carbene (NHC) precursors.
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    Rhodium(I) complexes with N-heterocyclic carbene ligands: synthesis, biological properties and catalytic activity in the hydrosilylation of aromatic ketones
    (Taylor & Francis Ltd, 2021) Hamdi, Naceur; Slimani, Ichraf; Mansour, Lamjed; Alresheedi, Faisal; Ozdemir, Ismail; Gurbuz, Nevin
    New rhodium(I) N-heterocyclic carbene (NHC) complexes 3a-f were synthesized in good yields by the reactions of rhodium dimer [Rh(OMe)(cycloocta-1,5-diene:COD)](2) with benzimidazolium salts 2a-f in tetrahydrofuran. All the complexes were characterized by IR, H-1-NMR, and C-13-NMR spectroscopy, DART-TOF mass spectrometry (for 3b, 3d and 3f) and elemental analysis. All complexes were used as catalysts in the hydrosilylation of acetophenone derivatives with triethylsilane at 80 degrees C for 1 h. These Rh(I) NHC showed good catalytic performance for the hydrosilylation of acetophenone derivatives by using 1 mol % of the rhodium complexes. In addition the new rhodium(I) NHC complexes were tested against MCF7 and MDA-MB-231 cancer cells, Micrococcus luteus LB 14110, Listeria monocytogenes ATCC 19117, Salmonella Typhimurium ATCC 14028, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa and Candida albicans microorganisms. The synthesized rhodium(I) NHC complex 3f was found the most active against MCF7 cancer cells (half-growth inhibition concentration (IC50) = 0.3 mu g mL(-1)), as well as the most potent antimicrobial against L. monocytogenes ATCC 19117 (inhibition zone (IZ) = 29 mm). Moreover, the antioxidant activity determination of these complexes was studied with the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and compared with gallic acid and butylated hydroxytoluene.
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    Ruthenium(II) complexes bearing benzimidazole-based N-heterocyclic carbene (NHC) ligands as potential antimicrobial, antioxidant, enzyme inhibition, and antiproliferative agents
    (Taylor & Francis Ltd, 2022) Boubakri, Lamia; Chakchouk-Mtiba, Ahlem; Naouali, Olfa; Mellouli, Lotfi; Mansour, Lamjed; Ozdemir, Ismail; Yaser, Sedat
    In this work, new substituted benzimidazolium salts 2a-d having different groups on the side chain have been synthesized and reacted with Ag2O to produce Ag(I) N-heterocyclic carbene (NHC) complexes 3a-d. Ag(I)-NHC complexes were used as a carben transfer agents to synthesize ruthenium(II)-NHC complexes 4a-d. The structures of all compounds were characterized by H-1 NMR, C-13 NMR and FT-IR spectroscopies and elemental analysis. The IC50 values of these complexes were determined by MTT assay against MCF7, MDA-MB-231 and HF cancer cell lines. The lowest MIC values were obtained for two complexes, 4b and 4d. The Ru(II)-NHC complexes generally triggered stronger bacterial growth inhibition than the metal-free benzimidazolium cations. Enzymatic inhibition investigation against acetylcholinesterase (AChE) and tyrosinase (TyrE) showed that 4b and 4d are the most potent inhibitors against AchE with an IC50 of 2.52 and 5.06 mu g mL(-1), respectively, and against TyrE with an IC50 of 19.88 and 24.95 mu g mL(-1), respectively. Antioxidant activity of the synthesized NHC ligands 2a-2d and their respective Ru(II)-NHC complexes 4a-4d was assessed by three different techniques: the 2.2-diphenyl-1-picrylhydrazyl (DPPH), the 2.2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals scavenging and the beta-carotene linoleic acid bleaching assay, showing that 4d has recorded an important antioxidant activity.
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    Synthesis and Investigation of Antimicrobial, Antioxidant, Enzymatic Inhibitory, and Antiproliferative Activities of Ruthenium (II) Complexes Bearing Benzimidazole-Based N-Heterocyclic Carbene (NHC) Ligands
    (Taylor & Francis Ltd, 2022) Hamdi, Naceur; Mansour, Lamjed; Al-Tamimi, Jameel; Al-Hazmy, Sadeq M.; Gurbuz, Nevin; Ozdemir, Ismail
    The benzimidazolium salts 2a-d were synthesized by quaternization of 1-(4-tet-buthylbenzyl) benzimidazole, with the corresponding benzysl bromide. The reactions were carried out in dimethylformamide at 70 degrees C for 48 h. Therefore, Ag2O and benzimidazolium salts 2a-d were reacted in dichloromethane at room temperature under dark and Ag(I)-NHC complex 3 was obtained in very good yields. The Ru(II)-NHC complexes (4a-d) were synthesized via transmetalation reaction from 3a-d. The structures of the obtained compounds were characterized by different spectroscopic techniques such as H-1 and C-13 NMR, elemental analysis, and melting point detection. The lowest MICs values were obtained with the two complexes 4b and 4d. Enzymatic inhibitory investigation against acetylcholinesterase (AChE) and tyrosinase (TyrE), showed that the two complexes 4b and 4d are the most potent inhibitors against (AchE) with an IC50 of 2.52 and 5.06 mu g mL(-1) respectively, and against (TyrE) with an IC50 of 19.88 and 24.95 mu g mL(-1) respectively. Screening of the selected N-Heterocyclic carbene (NHC) ligands (2a-2d) and their respective ruthenium (II) complexes (4a-4d) against colon carcinoma cells lines (HCT-116) and hepatocellular carcinoma cells lines (HepG-2). Furthermore, compounds 2c, 2d, 4b were showed weak cytotoxic action with IC50 ranging from 13.38 to 18.33 mu g in human colon carcinoma cancer cell lines and from 14.36 to 18.45 mu g in hepatocellular carcinoma cells lines.
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    Synthesis of palladium complexes containing benzimidazole core and their catalytic activities in direct C-H functionalization of five-membered heterocyclic bioactive motifs
    (Elsevier, 2024) Touj, Nedra; Bensalah, Donia; Mansour, Lamjed; Sauthier, Mathieu; Gurbuz, Nevin; Ozdemir, Ismail; Hamdi, Naceur
    Herein, we reported the synthesis of nine new PEPPSI-Pd(II)-N-heterocyclic carbene (NHC) complexes 3a-h containing benzimidazole core and examined their catalytic activities in the direct arylation of heteroaromatic species with aryl bromides and arylchlorides. Nine new Pd benzimidazole complexes were synthesized and their structures were elucidated by 1H and 13C NMR spectroscopy, FT-IR spectroscopy, and elemental analysis methods. In the 13C NMR spectra, NCHN peaks of Pd(II) complexes were observed between 159.7-161.5 ppm. Further, direct arylation reaction, using KOAc as base and DMAc as solvent under inert conditions, were carried out with the synthesized complexes in the presence of various aryl bromides and chlorides, and 2-acetyl furan, and furfuryl acetate 2-acetylthiophene and N-methylpyrrole-2- carboxaldehyde. Moreover, moderate to hig yields were obtained in the direct arylation of heteroarenes and aryl bromides under 1 mol% catalyst loading at 150 degrees C for 2 h loading conditions. The results showed that electron-donating and electron-withdrawing substituents on the aryl halides might produce coupling products in good yields in the presence of complexes 2a-d. Taken together, our findings are expected to contribute to the synthesis and design of palladium complexes containing benzimidazole core structures.
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    Synthesis, characterization and catalytic activity of PEPPSI-type palladium-NHC complexes
    (Elsevier Science Sa, 2021) Slimani, Ichraf; Mansour, Lamjed; Ozdemir, Ismail; Gurbuz, Nevin; Hamdi, Naceur
    Eight benzimidazolium salts (2a-h) with two nitrogen atoms substituted by various alkyl groups have been synthesized in high yields. The benzimidazolium salts were readily converted into the corresponding PEPPSItype palladium-NHC complexes (PEPPSI = pyridine-enhanced precatalyst preparation, stabilization, and initiation) (3a-h). The structures of all compounds were characterized by H-1 NMR, C-13 NMR, and IR spectroscopy as well as by elemental analysis techniques, which support the proposed structures. The catalytic activity of the PEPPSI-type palladium-NHC complexes was evaluated with respect to the direct C5-arylation of 2-substituted heteroaryl derivatives (thiophene, furan and thiazole) with various aryl bromides. This arylation occurs efficiently and selectively at the C5-position of the 2-substituted thiophene, furan and thiazole derivatives.
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    Synthesis, Characterization, Antimicrobial Properties, and Antioxidant Activities of Silver-N-Heterocyclic Carbene Complexes
    (Hindawi Ltd, 2023) Bensalah, Donia; Gurbuz, Nevin; Ozdemir, Ismail; Gatri, Rafik; Mansour, Lamjed; Hamdi, Naceur
    The emergence of antimicrobial resistance has become a major handicap in the fight against bacterial infections, prompting researchers to develop new, more effective, and multimodal alternatives. Silver and its complexes have long been used as antimicrobial agents in medicine because of their lack of resistance to silver, their low potency at low concentrations, and their low toxicity compared to most commonly used antibiotics. N-Heterocyclic carbenes (NHCs) are widely used for coordination of transition metals, mainly in catalytic chemistry. In this study, several N-alkylated benzimidazolium salts 2a-j were synthesized. Then, the N-heterocyclic carbene (NHC) precursor was treated with Ag2O to give silver (I) NHC complexes (3a-j) at room temperature in dichloromethane for 48 h. Ten new silver-NHC complexes were fully characterized by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), elemental analysis, and LC-MSMS (for complexes) techniques. The antibacterial and antioxidant activities of salt 2 and its silver complex 3 were evaluated. All of these complexes were more effective against bacterial strains than comparable ligands. With MIC values ranging from 6.25 to 100 g/ml, the Ag-NHC complex effectively showed strong antibacterial activity. Antioxidant activity was also tested using conventional techniques, such as 2, 2-diphenyl-1-picrylhydrazine (DPPH) and hydrogen peroxide scavenging assays. In DPPH and ABTS experiments, compounds 3a, 3b, 3c, 3e, 3g, and 3i showed significant clearance.
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    Synthesis, DFT calculations, and investigation of catalytic and biological activities of back-bond functionalized re-NHC-Cu complexes
    (Wiley, 2024) Yagmurlu, Ayse; Bugday, Nesrin; Yasar, Seyma; Boulebd, Houssem; Mansour, Lamjed; Koko, Waleed S.; Hamdi, Naceur
    Five copper complexes (3a-e) stabilized by ring-expanded back-bond functionalized N-heterocyclic carbene ligands (re-NHCs) were produced in the glovebox by reacting free re-NHC with CuI precursor. The potential of these re-NHC-Cu complexes as catalysts on the synthesis of mono- and di-(1,4-disubstituted-1,2,3-triazoles) by Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reactions was investigated. Various spectroscopic approaches were utilized to completely characterize the structures of the re-Cu-NHC complexes. Furthermore, density functional theory (DFT) calculations were carried out to get further insights into their molecular geometry and CuAAC reaction mechanism. The re-NHC-Cu complexes showed high activity on the CuAAC reaction in an open-air atmosphere at rt. The Gibbs free energies as well as the optimized geometries of the intermediates and the transition states of the determining step of the reactions catalyzed by 3a, 3e, and 3b complexes were computed. Complex 3e was found to be the most efficient catalyst among these re-NHC-Cu complexes. Additionally, re-Cu-NHC complexes were investigated for their biological activities, including antiproliferative, antioxidant, AChE and TyrE inhibition, and antiparasitic activity. The results showed that the 3b, 3d, and 3e complexes possessed strong antiproliferative activity against human colon carcinoma (HCT-116) and moderate cytotoxic activity against hepatocellular carcinoma (HepG-2) cell lines. In addition, effective selective antileishmanial effects were observed for the 3e compound against both promastigotes and amastigotes stages of L. major with an IC50 value of 0.027 and 0.39 mu M mL-1, respectively. These results demonstrate that these compounds are promising candidates for the treatment of colorectal cancer and leishmaniasis. re-NHC-Cu complexes have been synthesized and used as catalyst on CuAAC reactions. image