Three-component Reaction Of 2-aminopyridines Research Articles

Magnetic nanostructure-anchored mixed-donor ligand system based on carboxamide and N-heterocyclic thiones: An efficient support of CuI catalyst for synthesis of imidazo[1,2-a]pyridines in eutectic medium

A Cu-incorporated nanocatalyst has been developed by immobilizing copper iodide on a magnetically retrievable mixed-donor ligand system, containing carboxamide, imidazolidine-2-thione and imidazole-2-thione donor groups and characterized by various analysis techniques such as FT-IR, XRD, FE-SEM, EDX elemental mapping, TEM, ICP-OES, TGA, and VSM. The versatility of the synthesized nanocatalyst has been demonstrated for the one-pot synthesis of imidazo[1,2-a]pyridine derivatives via three-component reaction of 2-aminopyridines, aldehydes and alkynes using tetrabutyl ammonium bromide/glycerol (TBAB/glycerol) deep eutectic mixture as a sustainable medium. The nanocatalyst has exhibited high activity and stability under the reaction conditions with a negligible copper leaching, which can be due to the effective coordination interaction between the oxygen atom of carbonyl group as well as the sulfur atoms of thiocarbonyl groups in the supported ligand with copper iodide. The catalyst system can be readily recovered and successfully reused at least five times. Eco-friendly conditions, solvent recoverability, higher TON, wide functional group tolerance and lower E factor (0.2) are some other merits of the present work.

Design, Synthesis, In vitro Cytotoxic Activity Evaluation, and Study of Apoptosis Inducing Effect of New Styrylimidazo[1,2-a]Pyridines as Potent Anti-Breast Cancer Agents.

This paper reports synthesis, cytotoxic activity, and apoptosis inducing effect of a novel series of styrylimidazo[1,2-a]pyridine derivatives. In this study, anti-cancer activity of novel styrylimidazo[1,2-a]pyridines was evaluated. Styrylimidazo[1,2-a]pyridine derivatives 4a-o were synthesized through a one-pot three-component reaction of 2-aminopyridines, cinnamaldehydes, and isocyanides in high yield. All synthesized compounds 4a-o were evaluated against breast cancer cell lines including MDA-MB-231, MCF-7, and T-47D using MTT assay. Apoptosis was evaluated by acridine orange/ethidium bromide staining, cell cycle analysis, and TUNEL assay as the mechanism of cell death. Most of the synthesized compounds exhibited more potent cytotoxicity than standard drug, etoposide. Induction of apoptosis by the most cytotoxic compounds 4f, 4g, 4j, 4n, and 4m was confirmed through mentioned methods. In conclusion, these results confirmed the potency of styrylimidazo[1,2-a]pyridines for further drug discovery developments in the field of anti-cancer agents.

Peptide Nanofiber Templated Zinc Oxide Nanostructures as Non-precious Metal Catalyzed N-Arylation of Amines, One-Pot Synthesis of ImidazoHeterocycles and Fused Quinazolines

In the present study, peptide nanofiber was used to immobilize zinc oxide. This nanoparticle was prepared through self-assembly in an aqueous solution. The structural properties of the prepared catalyst were examined by a series of techniques, such as FT-IR, EDS, SEM, TEM, XRD, ICP-OES (inductively coupled plasma optical emission spectrometry), and ultraviolet–visible (UV–Vis) spectroscopy. TEM images showed the necklace model for peptide nanofiber decorated with zinc oxide. The versatility of the method was investigated by N-arylation using reaction of amines with hydroxybenzotriazole as a novel phenylating reagent, one-pot synthesis of imidazoheterocycles by a three-component reaction of 2-aminopyridine, aldehyde, terminal alkyne and preparation of tetracyclic quinazolinone ring by one-pot reaction of isatoic anhydride, amine, and ninhydrin. High yields, low cost of catalyst, environmental friendliness, efficient recovery and recyclability of catalyst are the most important features of this catalytic system.

Catalyst-free synthesis of imidazo [1,2-a] pyridines via Groebke multicomponent reaction

Deep eutectic solvents are becoming more popular nowadays since they are green, safe and often save raw materials and energy compared to organic solvent. Due to the importance of environmentally compatible solvent in multicomponent reactions, herein we report an efficient and sustainable catalyst-free synthesis of imidazo [1,2-a] pyridines via Groebke multicomponent reaction in choline chloride-based deep eutectic solvent. One-pot, three-component reaction of 2-amino pyridine, aromatic aldehydes and cyclohexyl isocyanide in six different choline chloride-based deep eutectic solvents in the absence of catalyst were examined. Urea–choline chloride was selected as an efficient solvent for this isocyanide-based multicomponent reaction and afforded the imidazo [1,2-a] pyridines in good yields of 57–87 % and reaction times of 2–6 h. The method has several advantages such as environmentally benign and biodegradable solvent, easy purification processes by a simple filtration and methodological simplicity.

ChemInform Abstract: Recent Developments in the Synthesis of Imidazo[1,2‐a]pyridines

AbstractReview: [151 refs.

Recent Developments in the Synthesis of Imidazo[1,2-a]pyridines

Advances in the last decade for the synthesis of the imidazo[1,2-<i>a</i>]pyridine scaffold from various substrates employing approaches such as multicomponent reactions, tandem processes, rearrangement reactions, inter- and intramolecular oxidative/reductive cyclizations, and transition-metal-catalyzed C–H activation are summarized in this review. The mechanisms for the selected transformations are also discussed. 1 Introduction 2 From 2-Aminopyridines 2.1 Revisiting Traditional Cyclocondensation 2.1.1 Regioselectivity in Cyclocondensation 2.2 Reactions of Carbonyl Compounds 2.3 Reactions of α,β-Unsaturated Carbonyl Compounds 2.4 Reactions of Nitroolefins 2.5 Reactions of Alkynes 2.6 Multicomponent Reactions 2.6.1 Three-Component Reaction of Aldehyde, 2-Aminopyridine, and Isocyanide 2.6.2 Three-Component Reaction of 2-Aminopyridine, Aldehyde, and Alkyne 2.6.3 Other Multicomponent Procedures 2.7 Reactions of N-Substituted 2-Aminopyridines 2.8 Miscellaneous Reactions 3 From Pyridines 3.1 Multicomponent Reactions 4 From Pyridinium Salts 5 From Imidazoles 5.1 Reactions of Heterocyclic Ketene Aminals 6 Miscellaneous Methods 7 Conclusion

ChemInform Abstract: Nano Fe3O4 Supported Biimidazole Cu(I) Complex as a Retrievable Catalyst for the Synthesis of Imidazo[1,2‐a]pyridines in Aqueous Medium.

AbstractThe title nanocatalyst is successfully employed for the synthesis of imidazopyridines in aqueous medium via three‐component reaction of 2‐aminopyridine, aldehydes, and phenylacetylene.

Efficient Synthesis of 3-Aminoimidazo[1,2-a] Pyridines Using Silica-Supported Perchloric Acid (HClO4-SiO2) as a Novel Heterogenous Catalyst

One pot three-component reaction of 2-amino pyridines, aldehydes and isocyanides in the presence of silicasupported perchloric acid (HClO4-SiO2), produces 3-aminoimidazo[1,2-a] pyridines in excellent yields. The reaction time is short and work up of reaction is very easy. New compounds were identified by IR, 1H NMR, 13C NMR and Mass spectrum. Keywords: 3-Aminoimidazo[1,2-a] pyridine, isocyanide, multi-component reaction, silica-supported perchloric acid (HClO4-SiO2), annulanes, calcium, heterocycles, medicinal chemistry, pyrazine, aldehydes

P2O5 Promoted One-Pot Synthesis of 3-aminoimidazo[1,2-a]pyridines under Solvent-Free Conditions

Phosphorus pentoxide is found to be a highly efficient biodegradable catalyst for the three-component reaction of 2-aminopyridines (I) with aromatic aldehydes (III) and isocyanides (II) under solvent-free conditions.

Synthesis of imidazo[1,2 a]pyridines via three-component reaction of 2-aminopyridines, aldehydes and alkynes

A novel three-component reaction towards the synthesis of imidazo[1,2 a]pyridines was independently developed based on 2-aminopyridines, aldehydes and alkynes, and thereby imidazo[1,2 a]pyridines were obtained in acceptable yields by the CuSO4/TsOH catalyzed three-component reaction.

Efficient and Simple Route for the Synthesis of N-(2-Pyridyl)-4-ethoxy-5-oxo-2,5-dihydro-1H-pyrrole-2,3-dicarboxylates

Three-component reaction of 2-aminopyridines, dialkyl acetylenedicarboxylates, triphenylphosphine, and ethyl chlorooxoacetate in the presence of triethylamine provides a sufficient route for the synthesis of dialkyl N-(2-pyridyl)-4-ethoxy-5-oxo-2,5-dihydro-1H-pyrrole-2,3-dicarboxylates in good yields.