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, Год журнала: 2024, Номер 89(5), С. 2847 - 2857

Опубликована: Фев. 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.

Язык: Английский

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Pd-Catalyzed Cross-Coupling of Cyclopropanols with 2-Br-p-Quinone Methides/2-Br-Cinnamate Esters Followed by a 1,6- and 1,4-Conjugate Addition Reaction

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Март 10, 2025

A novel cascade Pd-catalyzed cross-coupling reaction of cyclopropyl alcohol-derived ketone homoenolate with 2-Br-p-quinone methides and 2-Br-cinnamate esters followed by a 1,6- 1,4-conjugate addition is disclosed. This protocol converts various alcohols into homoenolate, which undergoes C-C bond formation 2-Br p-quinone esters. The salient features this methodology include its operational simplicity, mild conditions, an environmentally benign protocol, high efficiency, good to excellent yields, wide substrate scope.

Язык: Английский

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Photolytic Access to Oxaspirodecanes and Chromenes from Vinyldiazo Ester Cycloaddition with p-Quinones: A Vinylcarbene Is Not Involved

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

Synthetic methods that provide access to skeletally diverse heterocyclic motifs are poised accelerate drug discovery and streamline the synthesis of advanced intermediates materials. However, development such synthetic necessitates leveraging previously unexplored mechanistic pathways. We report herein an efficient blue light-emitting diode light-induced reaction vinyldiazoacetates quinones produces spirocyclic dihydrofurans, featuring synthetically challenging oxaspiro[4,5]decane core numerous medicinal agents, agrochemicals, natural products. In a departure from well-established photochemical reactivity diazo compounds, these reactions do not involve vinylcarbene formed by photolytic dinitrogen extrusion. Instead, they result photoexcitation quinone its triplet state with subsequent energy transfer vinyldiazo ester. The addition vinylogous carbon vinyldiazoacetate oxygen affords diradical collapses dihydrofuran upon loss dinitrogen. A strain release-driven Bro̷nsted acid-catalyzed rearrangement products unravels fused bicyclic ring system equally medicinally valuable chromenes, enabling facile skeletal diversification important motifs.

Язык: Английский

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Conjugated 1,8 and 1,6 Addition of Bis-Trimethylsilylketene Acetal to Activated p-Quinone Methides via Trifluoromethanesulfonic Anhydride

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

In this work, we studied the conjugated additions of bis-trimethylsilylacetalketene acetals (bis-TMSKA) to para-quinone methides (p-QMs), which are one most explored molecules for study and gained significant attention in organic chemistry due their versatile reactivity, particularly Michael addition reactions. study, trifluoromethanesulfonic anhydride (Tf2O) was used as an activating agent p-QMs, aiming achieve 1,6-Michael products least reported 1,8-Michael with pyridine substituents. The reactivity p-QMs derived from demonstrated distinct reaction pathways, leading formation δ γ lactones. investigation also involved synthesizing a 1-indanone carboxylic acids obtained 1,6-addition.

Язык: Английский

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Transition-metal-free regioselective synthesis of spiro-oxazolidines through [3 + 2] annulation reactions of azadienes with haloalcohols

RSC Advances, Год журнала: 2025, Номер 15(14), С. 10634 - 10638

Опубликована: Янв. 1, 2025

The transition-metal-free regioselective [3 + 2] annulation of azadienes with haloalcohols for the preparation highly functionalized spiro-oxazolidines is experimentally simple, broad substrate scope, good yields, and excellent regioselectivity.

Язык: Английский

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Palladium-catalyzed and ligand-controlled divergent cycloadditions of vinylidenecyclopropane-diesters with para-quinone methides enabled by zwitterionic π-propargyl palladium species

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(11), С. 3214 - 3224

Опубликована: Янв. 1, 2024

A palladium-catalyzed and ligand-controlled divergent synthesis of spiro-cyclohexadienones from p -quinone methides VDCP-diesters was realized via zwitterionic π-propargyl palladium species the mechanism clarified by DFT calculations.

Язык: Английский

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1,6-Conjugate hydrogenation of para-quinone methides to phenol-containing diaryl- and triarylmethanes under atmospheric pressure catalyzed by a metal–ligand bifunctional iridium catalyst

Journal of Catalysis, Год журнала: 2024, Номер unknown, С. 115812 - 115812

Опубликована: Окт. 1, 2024

Язык: Английский

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Metal-Free Regioselective Oxa-Michael Approach to Access Spirooxindole-Fused Tetrahydrofuran/Tetrahydropyran through [3 + 2]/ [4 + 2] Spirocyclization of Methyleneindolinones with Haloalcohols

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(13), С. 9389 - 9404

Опубликована: Июнь 24, 2024

An efficient one-pot metal-free, base-catalyzed method has been developed for the regioselective [3 + 2]/[4 2] annulation reactions of electrophilic methyleneindolinones with haloalcohols to furnish spirooxindole derivatives under mild reaction conditions. This afforded corresponding products two contiguous stereocenters including a quaternary center in good excellent yield (up 95%) moderate diastereoselectivities 12.5:1 dr) complete regioselectivity.

Язык: Английский

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A one-pot Synthesis of 2,3-Dihydrobenzofurans, Benzofuran-2(3H)-ones, and Indoles via [4 + 1] Annulation Reaction of ortho-substituted para-Quinone Methides and Bromonitromethane

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

A facile one-pot synthesis of oxygen- and nitrogen-containing benzoheterocycles has been achieved through [4 + 1] annulation para -quinone methides, followed by an oxidation/elimination sequence.

Язык: Английский

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Six-membered ring systems: With O and/or S atoms

Progress in heterocyclic chemistry, Год журнала: 2024, Номер unknown, С. 421 - 484

Опубликована: Янв. 1, 2024

Язык: Английский

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