Microcin B (McB) is a ribosomally synthesized antibacterial peptide. It contains up to nine oxazole and thiazole heterocycles that are introduced posttranslationally and are required for activity. McB inhibits the DNA gyrase, a validated drug target. Previous structure-activity analyses indicated that two fused heterocycles located in the central part of McB are important for antibacterial acti...

in the present study, some new bis-imidazole derivatives have been prepared through four-components condensation of 2,6-bis (4-aminophenyl)-4-p-tolylpyridine, benzaldehyde derivatives, benzil and ammonium acetate in presence of acetic acid. the present methodology offers several advantages such as good yields, simple procedure, milder conditions and the possibility of introducing a variety of s...

Five-membered heterocycles bearing an exocyclic double bond have been successfully used as substrates in asymmetric addition and cycloaddition reactions. Ylidene-heterocycles are attractive due to their high functionalization the presence of electrophilic conjugated bound that can participate nucleophilic reactions well reactions, which may be triggered by formation aromatic intermediates or pr...

this work described one pot syntheses of polysubstituted 2,6- dicyanoaniline and 2-(3-oxo-1,3-diarylpropyl) malononitrile derivatives in the presence of mgo nanoparticles (nps) under grinding conditions and microwave irradiation, respectively. the simple experimental procedure includes shorter reaction times, higher yields, lower cost and environmental friendliness. other remarkable features ar...

Many abundant and highly bioactive natural alkaloids contain an indolizidine skeleton. A simple, high yielding method to synthesize this scaffold from N-heterocycles was developed. A wide range of pyridines, quinolines and isoquinolines reacted with donor-acceptor (DA)-aminocyclopropanes via an ytterbium(iii) catalyzed [3 + 2] annulation reaction to give tetrahydroindolizine derivatives. The pr...

The growing importance of triarylarsines as ligands for transition metal catalysis has sparked recent interest in new synthetic routes to tertiary arsines that avoid hazardous arsenous chloride reagents. However, safer methods for the synthesis of lesser explored arsine heterocycles, especially those containing As-C(sp3) bonds, remain lacking. We demonstrate for the first time that bench stable...

A method for base-promoted arylation of arenes and heterocycles by aryl halides and aryl triflates is described. Additionally, in situ electrophilic trapping of ArLi intermediates generated in the reaction of benzyne with deprotonated arenes or heterocycles has been developed, providing rapid and easy access to a wide range of highly functionalized polyaryls. Base-promoted arylation methodology...

Isatins, derivatives of indole, represent important class of compounds belonging to nitrogen heterocycles. These compounds comprise synthetically vital substrates that are used as precursors for drug synthesis and raw materials for heterocycles etc. Research in this group of compounds has engrossed interest among scientific community in recent and past as Isatins are known to possess immense bi...

As a result of their easy availability in enantiomerically enriched form and their possession of synthetically transformable diverse functional groups, amino acids have been extensively used by synthetic organic and medicinal chemists as a chiral pool for access to heterocycles (monocycles, bicycles or polycycles, either bridged or fused). This review describes the syntheses of diverse asymmetr...