Non-C2-Symmetric Bis-Benzimidazolium Salt Applied in the Synthesis of Sterically Hindered Biaryls

A novel non-C2-symmetric bis-benzimidazolium salt derived from (±)-valinol has been prepared by a simple and straightforward process in good yield. The structure of bis-benzimidazolium salt provided a bulky steric group on the ethylene bridge; which facilitates the catalytic efficacy in the C(sp2)–C(sp2) formation. Its catalytic activity in Suzuki–Miyaura cross-coupling reaction of unactivated aryl chlorides has been found to have high efficacy in 1 mol% Pd loading. This protocol demonstrated the potential on the synthesis of sterically hindered biaryls.

Bridge, N-heterocyclic Carbene Complexes with Silver (I) and Palladium (II): Synthesis and Biological Activity

The present study describes synthesis, characterization (UV-Vis, FT-IR, 1HNMR, CHN analysis and melting point) and biological activity of new substituted benzimidazolium salt and their N-heterocycliccarbene (NHC) respective Ag(I) and Pd(II) complexes. The benzimidazole reacted with acetamide substituents at 90oC to form variety substituted of benzimidazolium salt to yield unsymmetrically substituted salt. Silver(I) complex was synthesized from the reaction of unsymmetrical substituted benzimidazolium salt with Ag2O using in-situ deprotonation technique to give derived structures in good yield.The use of Ag(I)-NHC complex is as transfer reagents by using the transmetallation technique to prepare respective Pd(II)-NHC. The biological activity. of the formed substituted benzimidazolium salts, Ag(I) and Pd(II) complexes was estimated against some bacteria strains S. aureus. And E.coli .The Ag(I)showed good activity while their corresponding salt and Pd(II)-NHC complex show less activity.

Red fluorescent zwitterionic naphthalenediimides with di/mono-benzimidazolium and a negatively-charged oxygen substituents

The C‒H/C‒X cross-coupling of a benzimidazolium salt with 2Br-NDI afforded two unprecedented zwitterionic NDIs with di/mono-benzimidazolium and an extra negatively-charged oxygen substituents. They exhibited intensified red fluorescence in polar solvents...

Synthesis, in vitro anticancer activities, and quantum chemical investigations on 1,3-bis-(2-methyl-2-propenyl)benzimidazolium chloride and its Ag(I) complex

1,3- Bis-(2-methyl-2-propenyl)benzimidazolium chloride and its Ag(I) complex are synthesized and the structures are elucidated using spectroscopies techniques. The molecular and crystal structures of the benzimidazolium salt are confirmed by X-ray crystallography. The molecular geometries of the benzimidazolium and its Ag(I) salt are analyzed using the B3LYP functional with the 6–311+G(d,p)/LANL2DZ basis set. The observed Fourier transform infrared and nuclear magnetic resonance isotropic shifts are compared with the calculated values. Besides, the quantum chemical identifiers, significant intramolecular interactions, and molecular electrostatic potential plots are used to show the tendency/site of the chemical reactivity behavior. The three-dimensional Hirshfeld surfaces and the associated two-dimensional fingerprint plots are applied to obtain an insight into the behavior of the interactions in the crystal. Both compounds are tested for their in vitro anticancer activities against DU-145 and MCF-7 cancer cells and L-929 non-cancer cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

A Novel Ag-N-Heterocyclic Carbene Complex Bearing the Hydroxyethyl Ligand: Synthesis, Characterization, Crystal and Spectral Structures and Bioactivity Properties

In this study, a novel silver N-heterocyclic carbene (Ag-NHC) complex bearing hydroxyethyl substituent has been synthesized from the hydroxyethyl-substituted benzimidazolium salt and silver oxide by using in-situ deprotonation method. A structure of the Ag-NHC complex was characterized by using UV-Vis, FTIR, 1H-NMR and 13C-NMR spectroscopies and elemental analysis techniques. Also, the crystal structure of the novel complex was determined by single-crystal X-ray diffraction method. In this paper, compound 1 showed excellent inhibitory effects against some metabolic enzymes. This complex had Ki of 1.14 0.26 µM against human carbonic anhydrase I (hCA I), 1.88±0.20 µM against human carbonic anhydrase II (hCA I), and 10.75±2.47 µM against α-glycosidase, respectively. On the other hand, the Ki value was found as 25.32±3.76 µM against acetylcholinesterase (AChE) and 41.31±7.42 µM against butyrylcholinesterase (BChE), respectively. These results showed that the complex had drug potency against some diseases related to using metabolic enzymes.

Nonisothermal crystallization kinetics, morphology, and tensile properties of polyphenylene sulfide/functionalized graphite nanoplatelets composites

Polyphenylene sulfide (PPS)/graphite nanoplates (GNPs) nanocomposites were manufactured by simple melt compounding. The GNPs were first functionalized using synthesized benzimidazolium salt to improve the compatibility with PPS matrix. The functionalized GNPs showed an exfoliated dispersion in PPS matrix, which also could significantly improve the tensile properties of composites. Differential scanning calorimetry was used to investigate the nonisothermal crystallization kinetics of PPS/functionalized GNPs composites. The results showed that the PPS/functionalized GNPs composites always had a higher crystallization peak temperature ( Tc) than pure PPS resin at different cooling rates due to the addition of GNPs. The GNPs could also play the role of heterogeneous nucleating agents to accelerate the crystallization; however, at high content, they could also limit the mobility of PPS macromolecular chains and hinder the crystallization. The Mo equation could be used to analyze the nonisothermal crystallization kinetics, whereas the Ozawa equation was not suitable for the nonisothermal crystallization process. Consistent with a previous analysis, the results also showed that the addition of GNPs could also decrease the crystallization activation energy ( Ec) of PPS resin at low content while increasing the Ec at high content.