Bis(amino)cyclopropenium Ion as a Hydrogen-Bond Donor Catalyst for 1,6-Conjugate Addition Reactions

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(7), P. 4994 - 5010

Published: March 15, 2021

The catalytic application of the bis(amino)cyclopropenium ion has been investigated in conjugate addition reactions. hydrogen atom, which is attached to cyclopropene ring salts, moderately acidic and can potentially serve as a hydrogen-bond donor catalyst some organic transformations. This hypothesis successfully realized 1,6-conjugate reactions p-quinone methides with various nucleophiles such indole, 2-naphthol, thiols, phenols, so forth. spectroscopic studies (NMR UV–vis) well deuterium isotope labeling clearly revealed that atom (C–H) present indeed solely responsible for catalyzing these In addition, also strongly indicate C–H activates carbonyl group methide through bonding.

Language: Английский

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Recent development in asymmetric organocatalytic domino reactions involving 1,6-addition as a key step

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 9(2), P. 572 - 592

Published: Nov. 15, 2021

This article highlights the significant development in stereoselective domino reactions involving 1,6-addition as a crucial step.

Language: Английский

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Multicomponent Synthesis of S-Benzyl Dithiocarbamates from para-Quinone Methides and Their Biological Evaluation for the Treatment of Alzheimer’s Disease

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(10), P. 6730 - 6741

Published: May 12, 2022

Multicomponent synthesis of biologically relevant S-benzyl dithiocarbamates from para-quinone methides, amines, and carbon disulfide are described under catalyst additive-free conditions. The reactions proceeded at room temperature in a short span time with excellent yields. One the synthesized compounds, 3e showed considerable acetylcholinesterase (AChE) inhibitory (51.70 + 5.63% 20 μm) antioxidant (63.52 ± 1.15 activities.

Language: Английский

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Asymmetric multifunctionalization of alkynes via photo-irradiated organocatalysis

Science Advances, Journal Year: 2022, Volume and Issue: 8(37)

Published: Sept. 14, 2022

Alkynes represent a family of pivotal and sustainable feedstocks for various industries such as pharmaceuticals, agrochemicals, materials, they are widely used important starting materials the production broad range chemical entities. Nevertheless, efficient structural elaborations alkynes in synthesis, especially asymmetric multifunctionalization alkynes, remain largely unexplored. It is thus imperative to develop new synthetic approaches, making use these richly available feedstocks, enabling their conversion value-added chiral molecules. Here, we disclose our findings on highly enantioselective by merging photochemistry phosphoric acid catalysis. Our reported one-pot protocol applicable all types alkyne substrates, incorporating three reactants fully atom-economic fashion produce optically enriched tetrasubstituted triaryl- diarylmethanes, scaffolds medicinal chemistry biological sciences.

Language: Английский

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Recent advances in the cyclization of para-quinone methides

Tetrahedron, Journal Year: 2023, Volume and Issue: 148, P. 133655 - 133655

Published: Oct. 9, 2023

Language: Английский

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Advances in Catalytic Asymmetric Reactions Involving o-Hydroxyphenyl Substituted p-Quinone Methides^★

Acta Chimica Sinica, Journal Year: 2023, Volume and Issue: 81(7), P. 793 - 793

Published: Jan. 1, 2023

o-Hydroxyphenyl substituted p-quinone methides (p-QMs) belong to a class of p-QMs with unique advantages.They not only maintain the high reactivity p-QMs, but also have more reactive and activation sites owing introduction hydroxyl group.Therefore, o-hydroxyphenyl wide applications in synthetic medicinal chemistry.The catalytic asymmetric 1,6-conjugate addition [4＋n] cycloaddition developed very rapidly recent years, which become efficient strategies for synthesis chiral oxygen-containing heterocycles arylmethanes potential bioactivity.This review summarizes reactions involving points out remaining challenges this research area, will open new window design type their involved reactions.

Language: Английский

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Organocatalytic Enantioselective 1,12‐Addition of Alkynyl Biphenyl Quinone Methides Formed In Situ

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: May 3, 2024

The chemistry of quinone methides formed in situ has been flourishing recent years. In sharp contrast, the development and utilization biphenyl are rare. this study, we achieved a remote stereocontrolled 1,12-conjugate addition for first time. presence suitable chiral phosphoric acid, alkynyl were generated from α-[4-(4-hydroxyphenyl)phenyl]propargyl alcohols, followed by enantioselective with indole-2-carboxylates. strategy enabled alcohols to serve as efficient allenylation reagents, providing practical access broad range axially allenes bearing (1,1'-biphenyl)-4-ol unit, which previously less accessible. Combined control experiments, density functional theory calculations shed light on reaction mechanism, indicating that enantioselectivity originates nucleophilic methides. Notably, not only versatile intermediates was confirmed but also organocatalytic 1,12-addition established.

Language: Английский

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Synthesis of 1,4-Dihydroquinolines and 4H-Chromenes via Organocatalytic Domino Aza/Oxa-Michael/1,6-Addition Reactions of para-Quinone Methides and Ynals

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(17), P. 11240 - 11249

Published: Aug. 11, 2020

An organocatalytic domino aza/oxa-Michael/1,6-addition reaction of ortho-tosylaminophenyl or ortho-hydroxyphenyl-substituted para-quinone methides and ynals has been developed. In the presence 20 mol % morpholine, this unprecedented cascade occurs readily in good yield (up to 99%), providing a highly efficient synthetic approach synthetically valuable 1,4-dihydroquinolines 4H-chromenes.

Language: Английский

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Palladium-Catalyzed Asymmetric (4 + 2) Annulation of γ-Methylidene-δ-valerolactones with Alkenes: Enantioselective Synthesis of Functionalized Chiral Cyclohexyl Spirooxindoles

Organic Letters, Journal Year: 2021, Volume and Issue: 23(3), P. 745 - 750

Published: Jan. 21, 2021

An unprecedented asymmetric catalytic (4 + 2) annulation reaction of aryl-substituted γ-methylidene-δ-valerolactones (GMDVs) with isatin-derived para-quinone methides (p-QMs) has been developed under the catalysis palladium(0) and (S,S,S)-(−)-Xyl-SKP, offering a new approach for diastereo- enantioselective synthesis chiral cyclohexadienone-fused cyclohexyl spirooxindoles. Significantly, three highly congested contiguous tetrasubstituted carbon atoms embedded in bispirocyclic skeleton, which two are vicinal quaternary stereogenic centers, forged an effective selective manner (up to 99% yield, up 95% ee, >20/1 dr). The current represents first exploration forming six-membered carbocycles chemistry both GMDVs p-QMs.

Language: Английский

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HFIP-catalyzed highly diastereoselective formal [4 + 2] cyclization to synthesize difluorinated multisubstituted chromans using difluoroenoxysilanes as C2 synthons

Chinese Chemical Letters, Journal Year: 2021, Volume and Issue: 33(6), P. 3007 - 3011

Published: Dec. 6, 2021

Language: Английский

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