Transmetallation Method Research Articles

Alkylation of morpholine and prolidine by phthalimide substituted Ru(II)–NHC catalysts

In this study, a series of benzimidazolium salts and silver-benimidazol-2-ylidene complexes were synthesized. The obtained silver complexes were converted into Ru(II)- benimidazol-2-ylidene complex using the transmetallation method. After elucidating the structures of these Ru(II)–NHC compounds, the synthesized ruthenium complexes were used in the alkylation reaction of cyclic amines to synthesize valuable derivatives such as pyrrolidine and morpholine. Pyrrolidine derivatives are extensively studied for their antimicrobial, antiviral, antifungal, anticancer, anti-inflammatory, anticonvulsant, cholinesterase inhibition, and carbonic anhydrase inhibition properties. Morpholine derivatives are particularly studied in the context of central nervous system (CNS) diseases. The yield of the catalytic products obtained was determined by GC. High selectivity and yield were achieved in the alkylation reactions of heterocyclic structures.

Binuclear Ag(I) and Cu(I)-complexes supported by imidazo[1,2-α]pyrimidine; synthesis, structure and DFT studies

Imidazo[1,2-α]pyrimidine, (1) was synthesized by a modified pathway through a neat reaction; corresponding Ag(I) complex (2) and Cu(I) complex (3) have been synthesized at room temperature and characterized by a series of spectroscopic techniques. Complex 2 has been synthesized after floating in the acetonitrile solution of ligand 1 into AgPF6; Cu(I) complex (3) has been synthesized by the transmetallation method. Finally, the solid state structure of 2 has been established by single crystal X-ray diffraction studies. The molecule 2 possesses ‘bicyclo’ like geometry. The formulation of 3 was supported by elemental analysis and HR-mass spectral studies. Interestingly, single crystal X-ray diffraction studies establish 2 as a dinuclear Ag(I) complex where each Ag(I) is coordinating by three Npym (pym = pyrimidine) from each ligand. Though the ligand is nonluminescent, yet Ag(I) complex (2) and Cu(I) complexes (3) are luminescent this may be due to closed cell d10-d10 interactions. DFT studies were also done to insight into the structures which also support the weak Ag(I)--Ag(I) and Cu(I)--Cu(I) interactions.

Gold(III) assisted C-N bond dissociation; Synthesis, structure, photoluminescence, and pharmacokinetic studies of 1,10/- phenanthroline-gold(III)-N-heterocyclic carbene

Herein we present synthesis, structure, luminescence, electrochemical properties, and intramolecular Au···H−C/N(sp2/sp3) hydrogen-bonding interactions of gold(III)-N-heterocyclic carbene complex fasten with 1,10- phenanthroline (phen). Starting from the proligand 1-methyl-3-((1-methyl-1H-benzo[d]imidazol-2-yl)methyl)-1H-imidazol-3-iumhexafluorophosphate (1.HPF6), the novel complex [Au(phen)(1)Cl][PF6]2, (2) has been synthesized by transmetallation method. Complex 2 is characterized by elemental analysis, IR, NMR, UV-Vis, fluorescence spectroscopy, and finally by single crystal X-ray diffraction analysis. Solid state structural analysis of complex 2 revealed gold(III) assisted C-N bond dissociation of the ligand. The bond parameters of the complex 2support square planar geometry. We compared the optoelectronic properties of 2 with that of the precursor [Au(phen)Cl2][PF6] to observe the influence of the NHC ligand. Electrochemical studies revealed Au(III)→Au(I) and Au(I)→Au(0) irreversible reductions. Complex 2 was also docked with B-cell lymphoma-2 (Bcl-2) and Topoisomerase proteins in order to know the affinity of the complex towards binding with different proteins. Pharmacokinetic analysis through SwissADME shows the potential of complex 2 to be used as a drug.

Dinuclear silver(I)‐ and gold(I)‐ N heterocyclic carbene complexes; Synthesis, structural characterizations, photoluminescence and theoretical studies

Herein, a new family of cationic Ag(I)- and Au(I)-, complexes ligated to a novel C∩N donor N- heterocyclic carbene (NHC) ligand 3-methyl-1-(1-methyl-2-methylbenzoyl)imidazolin-2-ylidene, (1) are described. Compound 3-methyl-1-(1-methyl-2-methylbenzoyl)imidazolium hexafluorophosphate (1.HPF6) essentially serves as a carbene precursor that delivers the NHC carbene to Ag(I) and Au(I). The corresponding complex [{Ag(1)}{PF6}]2,(2), was prepared using mild base Ag2O and 3-methyl-1-(1-methyl-2-methylbenzoyl)imidazolium hexafluorophosphate (1.HPF6). Transmetallation method was capitalized to synthesize [{Au(1)}{PF6}]2,(3). All the novel compounds were characterized by elemental analysis, 1H NMR, 13C NMR, HR mass spectroscopic studies, and finally by single crystal X-ray studies. X-ray crystallographic studies revealed that the dinuclear complex 2 and 3 adopt linear geometry (Ccarbene-Ag/Au-Nimi) where strong Ag–Ag and Au–Au interaction present. The structural assignments were further supported by DFT calculations. TDDFT studies have been performed to inside into the electronic properties.

Synthesis and Photophysical Properties of Symmetrical Mononuclear Gold(I)-N-Heterocyclic Carbene Complexes

Seven new mononuclear gold(I)-N-heterocyclic carbene (NHC) complexes, [bis(1-butyl-3-alkylbenzimidazolium)gold(I)] hexafluorophosphate (alkyl = methyl, ethyl, butyl, pentyl, hexyl, heptyl, benzyl), 1–7 were reported. All these complexes were successfully synthesized through transmetalation method of their respective silver(I)-NHC complexes, proved by elemental analyses, FTIR, 1H, 13C NMR and single crystal X-ray diffraction analyses. All the 13C NMR spectra of the complexes showed singlet peaks in the range of 189.0–191.2 ppm, belong to the carbene carbon that directly bonded with gold(I) ion, thus, suggesting the successful formation of gold(I)-NHC complexes. The single crystal X-ray diffraction data of 3 shows the presence of bis-NHC mononuclear complex with the chemical formula of [NHC-Au-NHC]·PF6 (NHC = 1,3-bisbutylbenzimidazol-2-ylidene ligand). At room temperature, complex 3 emits weak blue emission under UV light radiation. The photoluminescence study of 3 in solid state shows the excitation and emission spectra at 360 and 460 nm at room temperature while 306 and 406 nm at 77 K, respectively. With the aurophilic interaction excluded, these bands are attributed to metal-to-ligand transfer charge (MLCT) and ligand-centered π-π* transitions. The luminescence of 3 becomes more intense at 77 K compared to room temperature, with the large blue shift of the emission bands.

Microwave assisted synthesis of rhodium(Ⅰ) N-heterocyclic carbene complexes and their cytotoxicity against tumor cell lines

Organometallic rhodium(Ⅰ) complexes of the general type [(COD)(NHC)RhCl] (where COD = 1,5-cyclooctadiene, NHC = N-heterocyclic carbene) were prepared according to a two-step transmetalation method via a silver carbene intermediate. The procedure was supported by microwave irradiation allowing reduced reaction periods. The complexes were evaluated for cytotoxic effects in selected cancer cell lines, namely HT-29 colon adenocarcinoma, MDA-MB-231 breast carcinoma and MCF-7 breast adenocarcinoma, and generally triggered strong cytotoxic effects with IC50 values in the low micromolar range. Evaluation of structure-activity relationships clearly indicated a preference for branched isopropyl side chains at the nitrogen atoms of the NHC ligands versus non-branched ethyl side chains. Further studies on selected examples in HT-29 cells indicated that this could be the result of a higher cellular uptake.

Synthesis, characterization, DNA binding and anticancer activities of the imidazolidine-functionalized (NHC)Ru(II) complexes

Here, we present a study on the synthesis and biological properties of the ruthenium complexes having naphthyl substituted NHC ligands, which are of great importance for drug development studies. For this purpose, in our study, imidazolidine-functionalized Ru(II)NHC complexes containing naphthyl substitute group were synthesized and in vitro anticancer activity as well as DNA binding properties using agarose gel electrophoresis and ethidium bromide fluorescence quenching assay methods were determined in order to understand the biological activities. The Ru(II)NHC complexes were prepared from naphthyl-substituted Ag(I)NHC complexes and [RuCl2(p-cymene)]2 via the transmetallation method. These new complexes were characterized by using 1H NMR, 13C NMR, FTIR spectroscopic method and elemental analysis techniques. Consequently, complex 1d showed the highest anticancer activity in terms of IC30 and IC50 values against HepG2 cell line as 23.9 and 32.84 µM, respectively. Moreover, depending on the data obtained from agarose gel electrophoresis and fluorescence spectrophotometry techniques, 1b had the highest DNA binding property, which means that 1b behaved binding DNA in the cell as an intercalative manner rather than disrupting the integrity of cell membrane like 1d

New Ag(I) and Pd(II) complexes derived from symmetrical and asymmetrical NHC precursors: Synthesis, Characterization, Antibacterial activity, and Theoretical calculations

• New N-heterocyclic carbene precursors derived from the reaction of 2-chloro-N-(2,5-dimethylphenyl)-acetamide with imidazoles. • Ag(I) and Pd(II) complexes of the NHCs were synthesized. • The synthesized compounds have a good antibacterial activity against E. coli and S. aureus. • The estimated anticancer activity of the compounds was determined using docking calculation. New symmetric and asymmetric imidazolium salts namely 1-methyl-3-(2,5-dimethylphenyl)-acetamideimidazolium chloride ( 2 ), 1-benzyl-3-(2,5-dimethylphenyl)-acetamideimidazolium chloride ( 3 ) and 1,3-bis-(2,5-dimethylphenyl)-acetamideimidazolium chloride ( 4 ) were synthesized. In situ deprotonation technique was employed to synthesize Ag(I)-NHC complexes ( 5 - 7 ) from the reaction of Ag 2 O with the abovementioned ligand precursors. Subsequent reactions of Ag(I)-NHC complexes with [PdCl 2 (MeCN) 2 ] resulted the Pd(II)-NHC complexes ( 8 - 10 ) via transmetallation method. All the synthesized compounds were characterized using various techniques such as 1 H and 13 C NMR, FTIR and CHN analysis. The antibacterial activity of all the compounds was evaluated against bacterial strains E. coli as gram-negative and S. aureus as gram-positive bacteria using azithromycin as a standard antibiotic. The density functional theory (DFT) method was used to optimize the structures of the synthesized compounds using Gaussian 09 and Molecular Graphic Laboratory (MGL). Electronic energy, HOMO, LUMO, and dipole moment were calculated as well. Further, the estimated anticancer activity of the compounds was determined using docking calculations.

Redox, transmetalation, and stacking properties of tetrathiafulvalene-2,3,6,7-tetrathiolate bridged tin, nickel, and palladium compounds.

Here we report that capping the molecule TTFtt (TTFtt = tetrathiafulvalene-2,3,6,7-tetrathiolate) with dialkyl tin groups enables the isolation of a stable series of redox congeners and facile transmetalation to Ni and Pd. TTFtt has been proposed as an attractive building block for molecular materials for two decades as it combines the redox chemistry of TTF and dithiolene units. TTFttH4, however, is inherently unstable and the incorporation of TTFtt units into complexes or materials typically proceeds through the in situ generation of the tetraanion TTFtt4−. Capping of TTFtt4− with Bu2Sn2+ units dramatically improves the stability of the TTFtt moiety and furthermore enables the isolation of a redox series where the TTF core carries the formal charges of 0, +1, and +2. All of these redox congeners show efficient and clean transmetalation to Ni and Pd resulting in an analogous series of bimetallic complexes capped by 1,2-bis(diphenylphosphino)ethane (dppe) ligands. Furthermore, by using the same transmetalation method, we synthesized analogous palladium complexes capped by 1,1′-bis(diphenylphosphino)ferrocene (dppf) which had been previously reported. All of these species have been thoroughly characterized through a systematic survey of chemical and electronic properties by techniques including cyclic voltammetry (CV), ultraviolet-visible-near infrared spectroscopy (UV-vis-NIR), electron paramagnetic resonance spectroscopy (EPR), nuclear magnetic resonance spectroscopy (NMR) and X-ray diffraction (XRD). These detailed synthetic and spectroscopic studies highlight important differences between the transmetalation strategy presented here and previously reported synthetic methods for the installation of TTFtt. In addition, the utility of this stabilization strategy can be illustrated by the observation of unusual TTF radical–radical packing in the solid state and dimerization in the solution state. Theoretical calculations based on variational 2-electron reduced density matrix methods have been used to investigate these unusual interactions and illustrate fundamentally different levels of covalency and overlap depending on the orientations of the TTF cores. Taken together, this work demonstrates that tin-capped TTFtt units are ideal reagents for the installation of redox-tunable TTFtt ligands enabling the generation of entirely new geometric and electronic structures.

4-Vinylbenzyl and 2-morpholinoethyl substituted ruthenium (II) complexes: Design, synthesis, and biological evaluation

Abstract Recently, the medical applications of organoruthenium complexes have attention attracted to organometallic chemists and biochemists. In this study, 4-vinylbenzyl and 2-morpholinoethyl substituted (NHC)Ru(II)(η6-p-cymene) complexes were synthesized and in vitro DNA binding, cell cytotoxicity (anticancer activity) and genotoxicity properties were determined in order to understand the biological activities. These complexes have been prepared from the 4-vinylbenzyl and 2-morpholinoethyl substituted Ag(I)NHC complexes via transmetallation method. The characterization of the new (NHC)Ru(II)(η6-p-cymene) complexes was performed by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Also, molecular structure of complex 1b was obtained with single-crystal X-ray diffraction method. IC50 value of 1b against MCF-7 cell line was determined as 3.61 μM and for 1b, an oxidation effect was observed in the concentrations higher than 50 μg/mL. Comet assay unlike sister chromatid exchange (SCE) analysis data showed correlated results with cytotoxicity as well as DNA binding properties of the complexes.

Synthesis, characterization, in vitro antimicrobial and anticancer studies of new platinum N-heterocyclic carbene (NHC) complexes and unexpected nickel complexes

A series of bidendate pyridine-functionalized metal N-heterocyclic carbene (NHC) complexes with various wingtip substituents (R = methyl, phenyl and tert-butyl) had been prepared from silver oxide-mediated transmetalation method. The basic backbone of the NHC ligands were prepared in two stepwise reactions: reduction of the commercially available 2-benzoylpyridine, followed by halogenation to yield 2-(chloro(phenyl)methyl)pyridine. Subsequent reactions with different imidazoles gave the desired imidazolium salts (or NHC precursors) with different R groups at the N wingtip (R = Me, Ph, t-Bu). Transmetalation of the imidazolium salts into platinum NHC complexes were achieved by using Ag2O mediated method with Pt(cod)Cl2 as the transmetalating agent. On the other hand, nickel NHC complexes were obtained via one pot synthesis method with nickel chloride as the transmetalating agent and reflux in the presence of a base. Following recrystallisation, the molecular structure of Pt NHC complex ( ± )-5a had been successfully elucidated via single crystal X ray diffraction (XRD) analysis. The six-membered ring of the platinum NHC complexes adopted a boat conformation with the phenyl ring arranged at the axial position. Meanwhile, two unexpected nickel complexes, i.e. a simple nickel coordination complex and a nickelate complex, were obtained and studied using XRD. These Pt NHC complexes and unexpected Ni complexes were evaluated for their in vitro antimicrobial and anticancer activities against a panel of pathogenic microorganisms and three selected human cancer cell lines, including breast (MCF7), colon (HCT116) and oral (H103) cancer cells. Generally, the Pt NHC complexes displayed enhanced antimicrobial activities upon coordination to metals, as compared to the corresponding imidazolium salts i.e. NHC precursors, with minimum inhibitory concentration (MIC) values in micromolar (μM) range. A couple of platinum NHC complexes synthesized exhibited antimicrobial activities with MIC as low as 2 μM, which are comparable to silver NHC complexes with renowned antimicrobial profiles. Similarly, upon coordination to the metals, the cytotoxic effects of the platinum NHC complexes increased significantly as compared to the imidazolium salts. Among all, platinum NHC complex (±)-5c displayed significant cytotoxicities towards the cancer cells with IC50 values that are two to three times lower than that of the anticancer drug cisplatin. In summary, evidences for influence of both wingtip substituents and metals on the biological activities of the complexes have been found.

Synthesis and Characterization of Ag(I) Complexes Derived from New N-Heterocyclic Carbenes

Two new unsymmetrical imidazolium salts viz., [1-(4-ethylphenyl)-3-propyl-1H-imidazole-3-ium bromide] (3) and [1-(2,6-dimethylphenyl)-3-propyl-1H-imidazole-3-ium bromide] (4) have been synthesized via the reaction of propyl bromide with imidazole derivatives, [1-(4-ethylphenyl)-1Himidazole] (1) and [1-(2,6-dimethylphenyl)-1H-imidazole] (2) in absence of solvent. Then two new N-heterocyclic carbene silver complexes (5 and 6) were prepared through the reaction of imidazoluim salts (3 and 4) as a source of N-heterocyclic carbene with Ag2O by in situ method. These complexes can be used in the future as a transfer agent for preparing other transitional metal carbine complexes (NHCs) via transmetallation method. The formation of these compounds was confirmed by spectral analysis.

N-heterocyclic carbene based ruthenium complexes for selective β-C(sp3)-H functionalization of N-fused saturated cyclic amines

Herein, a series of new ruthenium(II) complexes with the general molecular formula [RuCl2(arene)(NHC)], (arene = η6-p-cymene, NHC = N-heterocyclic carbene) were synthesized from in situ prepared silver(I)-NHCs by the transmetallation method. These complexes were fully characterized by analytical and spectral methods. Ruthenium(II) complexes were tested as promising catalyst for selective β-C(sp3)-H functionalization of N-methylpiperidine with various aldehydes through hydrogen transfers in presence of external acidic additive. These eco-friendly cross-dehydrogenative couplings enable the production of C(3)-alkylated N-methylpiperidine derivatives without enamines with only carbon dioxide and water as benign by-product.

Investigations on structural and optical properties of chalcone dendrimer in Ag@TiO2 core–shell nanoparticles

The main focus of this research article is to observe the contributions of chalcone dendrimer in Ag@TiO2 core shell nanoparticles. The samples were synthesized by Redox transmetalation method. The structure of the samples in three molar ratio viz.1:1, 1:2, 1:5 (noted as A,B,C) with Poly Vinyl Pyrrolidone (PVP) as stabilizing agent were compared with the sample Ag@TiO2 of 1:2 molar ratio (noted as D) using zeroth generation triazolyl chalcone dendrimer as stabilizing agent. The prepared samples were structurally characterized by XRD and HRTEM analysis. The XRD and SAED analysis exhibited tetragonal body centered crystal structure with dhkl = 1.6 A, 2.4 A and 3.4 A. The lattice parameters were calculated for all the samples and the variations observed were reported. The grain size and dislocation density of the synthesized nanoparticles were calculated using Debye–Scherrer formula. From Williamson–Hall plot, it was identified that the lattice strain was increased in sample D in which chalcone dendrimer acted as stabilizing agent. The structural investigation showed the impact of stabilizing agent on the surface elements. Similarly, the optical characteristics were discussed based on UV-DRS and Photoluminescence studies. Using Kubelka–Munk function, the band gap energy was calculated and the difference observed in the band gap energy due to the impact of stabilizing agents on metal–metaloxide (Ag@TiO2) combination was analysed. The molar absorptivity (e) was calculated for all the samples using Beer–Lambert’s law and the difference in absorbance on using different stabilizing agent was discussed.

2-methyl-1,4-benzodioxan-substituted bis(NHC)PdX2 complexes: Synthesis, characterization and the catalytic activity in the direct arylation reaction of some 2-alkyl-heterocyclic compounds

Almost in all fields of chemistry, the C–C cross-coupling reactions such as the direct arylation reaction have attracted much attention and have advanced quickly in recent years due to the importance of environment-friendly properties. This study contains the synthesis of the 2-methyl-1,4-benzodioxan-substituted bis(NHC)PdX2 complexes and their catalytic activity in direct arylation reaction. The bis(NHC)PdX2 complexes have been prepared from the 2-methyl-1,4-benzodioxan-substituted Ag(I)NHC complexes via transmetallation method. The bis(NHC)PdX2 complexes have been characterized using 1H NMR, 13C NMR, FT-IR spectroscopy and elemental analysis techniques. The bis(NHC)PdX2 complexes have been examined as catalysts in the direct arylation reactions with 2-n-butylfuran, 2-n-butylthiophene and 2-isopropylthiazole, and have demonstrated excellent activity in these reactions.

Synthesis and Characterization of New Silver (I) N-Heterocyclic Ccarbene Ccomplex Dderived from Imidazol-2-ylidene salt

A new N, N'-imidazolium salt 1-(2,6-diisopropylphenyl)-3- (4,6-dimorpholino -1,3,5-traizine-2-yl)-1H-imidazol-3-ium chloride) as a precursor of N - heterocyclic carbene ligand was prepared via the reaction of 1 - (2, 6 - diisopropyl phenyl - 1H - imidazole) with 1, 3, 5 - triazine derivative bearing morpholine substituent (2, 6 -dimorpholine - 6- chloro-1, 3, 5-triaziazine). Linear coordi-nated Ag (І) NHC complex was synthesised via deprotonation of the imidazolium salt and reac-tion with Ag2O in darkness at room temperature by in situ method. The complex was synthesised for using as transfer agent to prepare another transition metals complexes by transmetallation method in the future. The imidazolium salt and their silver complex have been characterized by 1 H and 13C NMR spectroscopy as well as mass spectrometry.

Ruthenium(II)‐(p‐cymene)‐N‐Heterocyclic Carbene Complexes for the N‐Alkylation of Amine Using the Green Hydrogen Borrowing Methodology

Six ruthenium(II) complexes with the general molecular formula [RuCl2(NHC)(η6‐p‐cymene)] (NHC = N‐heterocyclic carbene) were synthesized by the transmetalation method from [RuCl2(η6‐p‐cymene)]2 and silver(I)‐NHC complexes. All complexes were fully characterized by analytical and spectral methods (FT‐IR, elemental analysis and 1H and 13C NMR). The solid‐state structure of one of the ruthenium complexes [dichloro‐{1‐[2‐(2‐ethoxyphenoxy)ethyl]‐3‐(3,5‐dimethylbenzyl)benzimidazol‐2‐ylidene}(p‐cymene) ruthenium(II)] has been established by single‐crystal X‐ray diffraction study, which revealed that the ruthenium atom adopt a classical piano‐stool coordination geometry. Under the optimised conditions, these ruthenium complexes were found to be efficient catalysts for N‐alkylation of aniline with arylmethyl alcohols using the hydrogen borrowing strategy, which is a cost‐effective and environmentally attractive reaction for the preparation of N‐alkylated amines.

New 4-vinylbenzyl-substituted bis(NHC)-Pd(II) complexes: Synthesis, characterization and the catalytic activity in the direct arylation reaction

This study contains the synthesis of the new 4-vinylbenzyl substituted bis(NHC)-Pd(II) complexes and their catalytic activity in direct arylation reaction. The bis(NHC)-Pd(II) complexes have been prepared from Ag(I)NHC complexes by transmetallation method. The complexes have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Also, all the complexes showed excellent activity as catalysts in the direct arylation reaction.

Chalcone dendrimer stabilized core–shell nanoparticles—a comparative study on Co@TiO2, Ag@TiO2 and Co@AgCl nanoparticles for antibacterial and antifungal activity

A series of core@shell nanoparticles (Co@TiO2, Ag@TiO2 and Co@AgCl) stabilized with zeroth generation triazolylchalcone dendrimer was synthesized using reduction transmetalation method. The coordination of chalcone dendrimer with silver ions was confirmed by UV–vis spectroscopy. The NMR spectrum ensures the number of protons and carbon signals in the chalcone dendrimer. The prepared samples were structurally characterized by XRD, FESEM and HRTEM analysis. The SAED and XRD analyses exhibited the cubic structure with dhkl = 2.2 Å, 1.9 Å and 1.38 Å. The antibacterial and antifungal activities of the dendrimer stabilized core@shell nanoparticles (DSCSNPs) were tested against the pathogens Bacillus subtilis, Proteus mirabilis, Candida albicans and Aspergillus nigir from which it is identified that the dendrimer stabilized core shell nanoparticles with silver ions at the shell (Co@AgCl) shows effectively high activity against the tested pathogen following the other core@shell nanoparticles viz Ag@TiO2 and Co@TiO2.

Synthesis, Characterization and Crystal Structure of New 2-Morpholinoethyl-Substituted Bis-(NHC)Pd(II) Complexes and the Catalytic Activity in the Direct Arylation Reaction

This paper contains the synthesis of the new 2-morpholinoethyl substituted bis-(NHC)Pd(II) complexes and their catalytic activity in direct arylation reaction. The new bis-(NHC)Pd(II) complexes have been prepared from Ag(I)NHC complexes by using transmetallation method. The new bis-(NHC)Pd(II) complexes have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Molecular and crystal structure of the complex 1a and its ligand (N-benzylbenzimidazole) were obtained by single crystal X-ray diffraction method. The new bis-(NHC)Pd(II) complexes exhibit activity in the reaction after being examined as catalysts in the direct arylation (C–H activation) reaction.