Recent developments in 1,6-addition reactions of para-quinone methides (p-QMs)

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(13), P. 1743 - 1778

Published: Jan. 1, 2020

In this review, we provide a comprehensive overview of recent progress in rapidly growing field by summarizing the 1,6-conjugate addition and annulation reactions p-QMs with consideration their mechanisms applications.

Language: Английский

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para‐Quinone Methides as Acceptors in 1,6‐Nucleophilic Conjugate Addition Reactions for the Synthesis of Structurally Diverse Molecules

European Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 2020(18), P. 2650 - 2692

Published: Feb. 28, 2020

para ‐Quinone methides ( p ‐QMs) are naturally occurring molecules that have been finding increasing synthetic applications in the last few years. The presence of two electronically different exocyclic conjugate substituents their structure, carbonyl and methylidene, leads to a pronounced reactivity owing polarization molecule. In this sense, those prone undergo attack nucleophiles terminal carbon double bond, behaving as vinylogous electrophiles generating 1,6‐addition products. context, years development catalytic approaches for 1,6‐nucleophilic addition reactions involving ‐QMs has attracted considerable attention. Considering extensive such found decades reactions, review we comprehensively discuss historical field, starting with early on natural product synthesis, going through seminal non‐stereoselective processes progressing cutting‐edge asymmetric‐catalyzed approaches.

Language: Английский

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Aza‐Michael Reaction: A Decade Later – Is the Research Over?

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(26)

Published: June 14, 2023

Abstract The 1,4‐conjugated addition of nitrogen centered nucleophiles to electron‐deficient alkenes, historically called the aza‐Michael addition, is one most significant and widely used reactions in modern synthetic organic chemistry. In last decade, great progress has been made this field namely development various catalytic systems. Fundamental advances involve use transition metal catalysts, organocatalysts, enzymes, ionic liquids, Brønsted Lewis acids bases. This Review aims critically analyze results research into aliphatic aromatic amines with Michael acceptors.

Language: Английский

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Organocatalytic regio-, diastereo- and enantioselective γ-additions of isoxazol-5(4H)-ones to β,γ-alkynyl-α-imino esters for the synthesis of axially chiral tetrasubstituted α-amino allenoates

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(6), P. 1243 - 1248

Published: Jan. 1, 2021

The chiral phosphoric acid catalyzed regio-, diastereo- and enantioselective reaction of isoxazol-5(4H)-ones with β,γ-alkynyl-α-imino esters has been developed.

Language: Английский

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Design, Synthesis, and Insecticidal Activity of Mesoionic Pyrido[1,2-a]pyrimidinone Containing Isoxazole/Isoxazoline Moiety as a Potential Insecticide

Journal of Agricultural and Food Chemistry, Journal Year: 2023, Volume and Issue: 71(22), P. 8381 - 8390

Published: May 23, 2023

Bean aphid (Aphis craccivora) resistance to commonly used insecticides has made controlling these pests increasingly difficult. In this study, we introduced isoxazole and isoxazoline, which possess insecticidal activity, into pyrido[1,2-a]pyrimidinone through a scaffold hopping strategy. We designed synthesized series of novel mesoionic compounds that exhibited range activities against A. craccivora. The LC50 values E1 E2 were 0.73 0.88 μg/mL, respectively, better than triflumezopyrim (LC50 = 2.43 μg/mL). Proteomics molecular docking analyses showed might influence the craccivora nervous system by interacting with neuronal nicotinic acetylcholine receptors (nAChRs). This research offers new approach advancement insecticides.

Language: Английский

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Regioselective Formal (3+2) Cyclization of Propargylic para-Quinone Methides (p-QMs) with β-Keto Carbonyls: Direct Access to (Fused)-Furans

Synlett, Journal Year: 2025, Volume and Issue: unknown

Published: April 24, 2025

Abstract We report a calcium(II)-catalyzed, base-promoted, formal (3+2) cyclization of para-quinone methides with 1,3-dicarbonyl derivatives to access furans, dihydrofurans, dihydrobenzofurans, and naphthofurans under solvent-free conditions. The reaction shows good substrate generality excellent regioselectivity.

Language: Английский

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Palladium-Catalyzed Asymmetric (2+3) Annulation of p-Quinone Methides with Trimethylenemethanes: Enantioselective Synthesis of Functionalized Chiral Spirocyclopentyl p-Dienones

Organic Letters, Journal Year: 2020, Volume and Issue: 22(11), P. 4171 - 4175

Published: May 20, 2020

A novel asymmetric catalytic (2+3) annulation of p-quinone methides with CN-substituted trimethylenemethane is described under palladium catalysis, providing an alternative approach for the enantioselective construction highly functionalized chiral spirocyclopentyl p-dienones. Driven by significant improvement in reactivity and enantioselectivity, a type non-C2-symmetric phosphoramidite ligand from chirality-matched combination (S)-BINOL sterically demanding amine derived l-hydroxyproline evolved explored protocol presented here.

Language: Английский

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Asymmetric Synthesis of Isoxazol-5-ones and Isoxazolidin-5-ones

Synthesis, Journal Year: 2020, Volume and Issue: 53(01), P. 107 - 122

Published: Oct. 12, 2020

Abstract Isoxazol-5-ones and isoxazolidin-5-ones represent two important classes of heterocycles, with several applications as bioactive compounds versatile building blocks for further transformations. Unlike the parent aromatic isoxazoles, presence one or stereocenters in ring renders their asymmetric construction particularly important. In this review, starting from description general features differences between these related compound families, we present an overview on most enantioselective synthesis strategies to access heterocycles. Both chiral metal catalysts organocatalysts have recently been successfully employed task some promising approaches will be discussed. 1 Introduction 2 Nucleophiles 2.1 C-Nucleophiles 2.2 N-Nucleophiles 2.3 Cyclization Processes 3 Asymmetric Construction Isoxazolidin-5-ones 3.1 Enantioselective α-Functionalizations 4 Arylideneisoxazol-5-ones Conjugated Addition 5 Conclusions

Language: Английский

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Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

Beilstein Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 17, P. 2585 - 2610

Published: Oct. 18, 2021

Nitrogen-containing scaffolds are ubiquitous in nature and constitute an important class of building blocks organic synthesis. The asymmetric aza-Michael reaction (aza-MR) alone or tandem with other reaction(s) is synthetic tool to form new C–N bond(s) leading developing libraries diverse types bioactive nitrogen compounds. synthesis application a variety organocatalysts for accomplishing highly useful syntheses without causing environmental pollution compliance ‘Green Chemistry” has been landmark development the recent past. Application many these extended aza-MR during last two decades. present article overviews literature published 10 years concerning amines amides catalysed by organocatalysts. Both organocatalysts, i.e., those acting through non-covalent interactions working covalent bond formation have applied aza-MR. Thus, review includes examples wherein cinchona alkaloids, squaramides, chiral amines, phase-transfer catalysts bifunctional thioureas used, which activate substrates hydrogen formation. Most reactions accompanied high yields enantiomeric excesses. On hand, N-heterocyclic carbenes pyrrolidine derivatives such as iminium ions also included. Wherever possible, comparison made between efficacies various

Language: Английский

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Rapid synthesis of fully substituted arylideneisoxazol-5(4H)-one using zinc oxide nanoparticles

Research on Chemical Intermediates, Journal Year: 2023, Volume and Issue: 49(10), P. 4603 - 4619

Published: July 9, 2023

Language: Английский

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