Recent advances in transition metal-free annulation toward heterocycle diversity based on the C–N bond cleavage of enaminone platform

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(12), P. 2356 - 2369

Published: Jan. 1, 2022

Enaminones and analogous stable enamines are well known as platform building blocks in organic synthesis for the construction of heterocyclic compounds, especially N-heterocycles. To date, enaminones have been successfully employed various 5- or 6- membered heterocycles. Recently, synthetic protocols accomplished by diversity-oriented annulation reactions based on C-N bond cleavage gained notable success. In this review, development transition metal-free product featuring a is reviewed.

Language: Английский

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Recent Advances in the Synthesis of C2‐Functionalized Pyridines and Quinolines Using N‐Oxide Chemistry

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 363(1), P. 2 - 39

Published: Oct. 12, 2020

Abstract While remarkable progress has recently been made for the direct C−H‐functionalization of azines, its application is still limited by a lack accessible functional groups (primarily carbon‐based) and poor regioselectivity. In contrast, C2‐functionalized pyridines quinolines can be easily synthesized treating readily available N ‐oxides with various reagents under appropriate activation conditions. This review seeks to comprehensively document synthetic methods introducing at C2 position quinolines. this work, we highlight recent developments in C2‐functionalization pyridine quinoline address both mechanisms regioselectivity reactions. We also describe pathways reactive species involved these processes number medically relevant nitrogen heteroaromatics. magnified image

Language: Английский

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The Domino Chromone Annulation and a Transient Halogenation-Mediated C–H Alkenylation toward 3-Vinyl Chromones

Organic Letters, Journal Year: 2020, Volume and Issue: 22(24), P. 9518 - 9523

Published: Dec. 3, 2020

Reported in this paper is a step economical method toward the general synthesis of 3-vinyl chromones via reactions between readily available o-hydroxyphenyl enaminones and various alkenes. The domino C–H alkenylation chromone annulation are involved, which enables products using both terminal internal alkenes key process transient halogenation.

Language: Английский

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Transition metal-free synthesis of 3-trifluoromethyl chromones via tandem C–H trifluoromethylation and chromone annulation of enaminones

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(18), P. 2770 - 2775

Published: Jan. 1, 2020

The synthesis of 3-trifluoromethyl chromones has been realized via transition metal-free reactions o-hydroxyphenyl enaminones and the Langlois reagent cascade C–H trifluoromethylation chromone annulation.

Language: Английский

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Transition metal-free tunable synthesis of 3-(trifluoromethylthio) and 3-trifluoromethylsulfinyl chromones via domino C-H functionalization and chromone annulation of enaminones

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: 35(11), P. 109683 - 109683

Published: March 2, 2024

Language: Английский

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Transition‐Metal‐Free C(sp²)‐H Dithiocarbamation and Chromone Annulation Cascade for 3‐Dithiocarbamyl Chromone Synthesis

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(20), P. 4811 - 4816

Published: Aug. 26, 2021

Abstract The transition‐metal‐free synthesis of 3‐dithiocarbamyl chromones by reacting o ‐hydroxyphenylenaminones with thiurams in the presence KIO 3 and TEMPO is reported. In addition, synthesized herein have been successfully utilized as starting materials pyrimidines 3‐(benzylthio)chromones via featured chromone ring opening C−S bond cleavage, respectively. magnified image

Language: Английский

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Chromone, A Privileged Scaffold in Drug Discovery: Developments in the Synthesis and Bioactivity

Mini-Reviews in Medicinal Chemistry, Journal Year: 2021, Volume and Issue: 22(7), P. 1030 - 1063

Published: Nov. 24, 2021

Chromones are the class of secondary metabolites that broadly occur in plant kingdom a noticeable quantity. This rigid bicyclic system has been categorized "as privileged scaffolds compounds" medicinal chemistry. Their wide biological responses have made them an important moiety drug discovery program. review provides updates on various methods synthesis chromones and applications Various synthetic strategies for construction include readily available phenols, salicylic acid its derivatives, ynones, chalcones, enaminones, 2-hydroxyarylalkylketones as starting materials. Synthesis by using metal, metal-free, nanomaterials different other catalysts is herein included. Details diverse activities chromone derviatives, such anti-cancer, antimicrobial, anti-viral, anti-inflammatory, antioxidant, Monoamine Oxidase-B (MAO-B) inhibitors, anti- Alzheimer's agents, anti-diabetic having antihistaminic potential, acting antiplatelet discussed.

Language: Английский

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Fluorescent sulfur quantum dots for environmental monitoring

Nanotechnology Reviews, Journal Year: 2025, Volume and Issue: 14(1)

Published: Jan. 1, 2025

Abstract The importance of environmental monitoring is on the rise, driven by increased pressure natural environment during age urbanization and industrialization. To address this demand, it necessary to have fast dependable probes for real-time with precision sensitivity. Analytical utilizing sulfur nanoparticles offer a modern alternative, exhibiting ability identify range analytes. discovery zero-dimensional quantum dots, such as dots (SQDs), unique properties, including optical characteristics, high hydrophilicity, low toxicity, cost-effectiveness, has positioned SQDs advancing luminescent nanomaterials. hold great potential fluorescence sensing, making them promising candidates monitoring. This article reviews recent studies synthesis using various methods highlights their applications sensing materials detecting heavy metal ions other hazardous molecules. provides valuable insights into production high-quality tailored applications, offering guidance researchers aiming enhance technologies contamination detection.

Language: Английский

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An update on the advances in chromone and the derivatives synthesis based on the key chromone annulation of o-hydroxyaryl enaminones

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: unknown, P. 110784 - 110784

Published: Dec. 1, 2024

Language: Английский

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Recent Progress in Enolonium Chemistry under Metal‐Free Conditions

The Chemical Record, Journal Year: 2021, Volume and Issue: 22(1)

Published: Aug. 21, 2021

Abstract Umpolung approach through inversion of the polarity conventional enolates, has opened up an unprecedented opportunity in cross‐coupling via alkylation. The enolonium equivalents can be accessed either by hypervalent iodine reagents, activation/oxidation amides, or oxidation alkynes. Under umpolung conditions, highly basic conditions required for classical enolate chemistry avoided, and they couple with unmodified nucleophiles such as heteroatom donors electron‐rich arenes.

Language: Английский

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