Cyanopropyl functionalized benzimidazolium salts and their silver N‐heterocyclic carbene complexes: Synthesis, antimicrobial activity, and theoretical analysis

Abstract

The reaction of N-substituted benzimidazole with 4-bromobutyronitrile gives the corresponding benzimidazolium salts as N-heterocyclic carbene (NHC) precursors. Silver(I) carbene complexes are synthesized by the reaction of the corresponding benzimidazolium salts with Ag 2 O in dichloromethane. These new NHC precursors and Ag-NHC complexes were characterized by spectroscopy techniques and also screened for their antibacterial activities against the standard bacterial strains Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Enterococcus faecalis, and the standard fungal strains Candida albicans and Candida glabrata, and promising results were achieved. The compounds were also analyzed by density functional theory (DFT)/time-dependent DFT and docking methods.

Benzimidazolium Salts Bearing Nitrile Moieties: Synthesis, Enzyme Inhibition Profiling, and Molecular Docking Analysis for Carbonic Anhydrase and Acetylcholinesterase

“…A method similar to that of compound 1 a was used to synthesize compound 1 d from 1‐(2,3,5,6‐tetramethylbenzyl)benzimidazole (0.73 g, 3.3 mmol) and 3‐cyanopropyl bromide (0.79 g, 3.3 mmol). This known compound was synthesized and characterized by NMR, IR, m.p and elemental analysis, and our results are in agreement with the literature [51] . 1 H‐NMR (400 MHz, CDCl 3 298 K), δ: 2.19 and 2.23 (s, 12H, ‐NCH 2 C 6 H(C H 3 ) 4 ); 2.37 (p., 2H, J : 6.5 Hz, −NCH 2 C H 2 CH 2 CN); 2.75 (t, 2H, J : 6.3 Hz, −NCH 2 CH 2 C H 2 CN); 4.97 (t, 2H, J : 6.5 Hz, −NC H 2 CH 2 CH 2 CN); 5.64 (s, 2H, −NC H 2 C 6 H(CH 3 ) 4 ); 7.06 (s, 1H, −NCH 2 C 6 H (CH 3 ) 4 ); 7.49–7.64 (m, 3H, Ar‐ H ); 7.85 (d, 1H, J =8.2 Hz, Ar‐ H ); 10.45 (s, 1H, NC H N).…”

“…This known compound was synthesized and characterized by NMR, IR, m.p and elemental analysis, and our results are in agreement with the literature. [51]…”

“…Although there is existing literature on the ionic liquid properties and catalytic activities of imidazolium salts [49,50] that contain the nitrile group, research on the biological properties of benzimidazolium salts that contain this same group remains limited. [51] Herein, a range of benzimidazolium salts, substituted with nitrile group, were synthesized. Their enzyme inhibition abilities against AChE and hCAs were investigated.…”

Comprehensive Insights into Medicinal Research on Imidazole-Based Supramolecular Complexes

“…This unique ability facilitated the formation of coordination or supramolecular structures. Nitrogen-functionalized benzimidazole compound II155 gave moderate antibacterial activity [ 313 ].…”

Facile Synthesis of Benzimidazoles via Oxidative Cyclization of Acyclic Monoterpene Aldehyde with Diamines: Studies on Antimicrobial and in Vivo Evaluation of Zebrafish

“…Many attempts have been made to create benzimidazole derivatives in this context. Due to the rise in bacterial resistance, there has been much interest in developing a novel category of antimicrobial substances that are efficient against Gram‐positive and Gram‐negative bacteria such as S. aureus , E. faecalis , P. aeruginosa and E. coli , as well as fungi C. albicans using the disc‐diffusion method [18a–d] . Furthermore, the development of embryotoxicity in zebrafish was studied using ( 1a ) and ( 3a – l ) benzimidazole derivatives with electron‐donating groups ( 3a – c , 3h and 3l ) their good non‐toxicity activities, we decided to synthesize electron‐withdrawing ( 3d – g , 3i – k ) benzimidazole derivatives and screened the modified compounds for their potential anti‐bacterial and anti‐fungal applications [19a–c] .…”