Tetrasubstituted imidazoles as incognito Toll-like receptor 8 a(nta)gonists

Small-molecule modulators of TLR8 have drawn much interests as it plays pivotal roles in the innate immune response to single-stranded RNAs (ssRNAs) derived from viruses. However, their clinical uses are limited because they can invoke an uncontrolled, global inflammatory response. The efforts described herein culminate in the fortuitous discovery of a tetrasubstituted imidazole CU-CPD107 which inhibits R848-induced TLR8 signaling. In stark contrast, CU-CPD107 shows unexpected synergistic agonist activities in the presence of ssRNA, while CU-CPD107 alone is unable to influence TLR8 signaling. CU-CPD107’s unique, dichotomous behavior sheds light on a way to approach TLR agonists. CU-CPD107 offers the opportunity to avoid the undesired, global inflammation side effects that have rendered imidazoquinolines clinically irrelevant, providing an insight for the development of antiviral drugs.

Synthesis, Biological Evaluation and Docking Studies of 1,2,4,5-Tetrasubstituted Imidazoles as Antibacterial Agents: Use of Niobia Supported Heteropoly Tungstate as an Efficient Reusable Catalyst

The synthesis of novel 1,2,4,5-tetrasubstituted imidazoles was carried out in a single molecular motif using niobia supported heteropoly tungstate as a mild and efficient reusable catalyst. The condensation of 3-aryl-1-phenyl-1H-pyrazole-4-carbaldehyde, aromatic amine, benzil, ammonium acetate and heteropoly tungstate supported on niobia was achieved under both conventional and non-conventional conditions. The employed protocol provides significant advantages, as it exhibits a remarkable catalytic activity on recovery, excellent yields and excellent reaction efficacy within short reaction times between 1-2 h (conventional) and 1-3 min (microwave radiation). All the obtained compounds were characterized by means of spectral data and elemental analysis. They were also screened for their antibacterial activity. To predict the binding mode of compounds with glutamine-fructose-6-phosphate transaminase (GlcN6P synthase), docking studies were performed.

Magnetic nanoparticle-supported sulfonic acid as a green catalyst for the one-pot synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions

In this work, magnetic nanoparticle-supported sulfonic acid (γ-Fe2O3-SO3H) is used as an efficient catalyst in the synthesis of 2,4,5-trisubstituted imidazoles and 1,2,4,5-tetrasubstituted imidazoles in a short time (40–70 min for trisubstituted imidazoles and 30–40 min for tetrasubstituted imidazoles) and high-purity products were obtained (92–98% for trisubstituted imidazoles and 94–98% for tetrasubstituted imidazoles) in simple multicomponent reactions. The structure of these products was confirmed via FT-IR and NMR. Green and recyclable catalysts, eco-friendly and solvent-free conditions, high catalytic activity, shorter reaction time, easy recovery by an external magnet, high purity, and excellent yields are some features of these reactions.

Electrochemistry synthesis of 1,2,4,5-tetrasubstituted imidazoles from enamines and benzylamines

An electrochemical method for the synthesis of 1,2,4,5-tetrasubstituted imidazoles is developed under undivided electrolytic conditions, which have been realized based on electrochemical C(sp3)–H Amination via enamines and amine. It uses...

Correction: An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent

Correction for ‘An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent’ by Thanh Thi Nguyen et al., RSC Adv., 2019, 9, 38148–38153, DOI: 10.1039/C9RA08074K.