Synthesis of Fluorine-Containing Multisubstituted Oxa-Spiro[4,5]cyclohexadienones via a Fluorinated Alcohol-Catalyzed One-Pot Sequential Cascade Strategy

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 2847 - 2857

Published: Feb. 16, 2024

In recent years, the application of fluorinated alcohols as solvents, cosolvents, or additives has become important in modern organic synthesis. However, their potential efficient catalysts synthesis not been well-explored. this article, we report on development a one-pot sequential cascade reaction p-quinone methides with difluoroenoxysilanes using hexafluoroisopropanol catalyst. This allows for preparation multisubstituted oxa-spiro[4,5]cyclohexadienones. By 50 mol % 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP), proceeds smoothly to yield 1,6-conjugated products, which are then subjected oxidative dearomatization/hemiacetalization PhI(OAc)2. The overall process affords moderate high yields and excellent diastereoselectivities.

Language: Английский

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P(NMe₂)₃-Mediated Umpolung Spirocyclopropanation Reaction of p-Quinone Methides: Diastereoselective Synthesis of Spirocyclopropane-Cyclohexadienones

Organic Letters, Journal Year: 2020, Volume and Issue: 22(21), P. 8376 - 8381

Published: Oct. 12, 2020

An unprecedented umpolung spirocyclopropanation reaction of p-quinone methides and α-keto carbonyls is described. Our strategy based on 1,6-conjugate addition intramolecular nucleophilic substitution offers a new method for effective access to series highly functionalized spirocyclohexadienonyl cyclopropanes having two vicinal quaternary carbons in ≤98% yield >20:1 dr. Significantly, cyclic acyclic topological structures as 1,1-dipole one-carbon synthons have distinct influence the stereochemistry products, showing reversal diastereoselectivity this P(NMe2)3-mediated spirocyclopropanation.

Language: Английский

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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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Unmasking the reverse reactivity of cyclic N-sulfonyl ketimines: multifaceted applications in organic synthesis

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(72), P. 9010 - 9028

Published: Jan. 1, 2021

This feature article covers the recent status on reactivities of α-alkyl cyclic N -sulfonyl ketimines as resourceful nucleophiles, targeting fused carbo- and heterocycles, aza-arenes etc . In addition, mechanistic studies have been presented.

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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Transition-metal-catalyzed switchable divergent cycloaddition of para-quinone methides and vinylethylene carbonates: Access to different sized medium-sized heterocycles

Chinese Chemical Letters, Journal Year: 2022, Volume and Issue: 33(10), P. 4549 - 4558

Published: Jan. 31, 2022

Language: Английский

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Stereoselective Reductive Coupling Reactions Utilizing [1,2]-Phospha-Brook Rearrangement: A Powerful Umpolung Approach

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(15), P. 10325 - 10338

Published: July 17, 2023

[1,2]-Phospha-Brook rearrangement entails the generation of α-oxygenated carbanions via umpolung process. Recently, these anionic species have been widely utilized for several C–C bond forming strategies, providing various useful frameworks that are difficult to access through conventional approaches. However, application this powerful methodology in development chiral strategies is still at nascent stage due challenges involved controlling chemoselectivity and enantioselectivity. This synopsis provides a detailed summary diastereo- and/or enantioselective chemical transformations using [1,2]-phospha-Brook rearrangement.

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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Addition of sulfonylphthalides to para-quinone methides: Selective 1,6-additions and oxidative annulations

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(12), P. 2504 - 2508

Published: Jan. 1, 2023

KO t Bu mediated addition of sulfonylphthalides to p -quinone methides led the selective synthesis isochroman-1,4-diones and products. Furthermore, a few products were transformed into functionalized heterocyclic molecules.

Language: Английский

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