Relay Catalysis-Enabled Enantioselective Annulations of β,γ-Alkynyl-α-imino Esters with 1,3-Diones for the Divergent Synthesis of Chiral Oxacycles

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Фев. 19, 2025

A novel protocol for the chemically divergent synthesis of chiral oxacycles has been developed using organo/metal relay catalysis. The methodology integrates a stereospecific Mannich reaction between β,γ-alkynyl-α-imino esters and 1,3-diones catalyzed by bifunctional squaramide, followed Lewis acid-catalyzed regioselective annulation reactions. By switching acid employed, we achieved pathway to construct structurally related pyran furan derivatives from common intermediate. (3+3) (3+2) products were obtained in high yields excellent stereoselectivities. Comprehensive mechanistic studies conducted establish mechanism.

Язык: Английский

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Enantioselective Synthesis of Spirooxindole‐pyran and furan Scaffolds via Copper‐Catalyzed Formal (3+3) and (3+2) Cycloaddition of Isatin‐derived Propargylic Esters

Chemistry - A European Journal, Год журнала: 2024, Номер 31(8)

Опубликована: Дек. 12, 2024

Herein, we report a copper-catalyzed enantioselective formal (3+3) and (3+2) cycloaddition reaction of isatin-derived tertiary propargylic esters with N,N-dimethylbarbituric acid 4-hydroxycoumarins, respectively. In this process, the ester serves as both C3- C2-synthons, facilitating synthesis optically active spirooxindole-pyran furan scaffolds featuring an all-carbon quaternary stereocenter. The delivers these spirocyclic frameworks in good yields high enantioselectivities. Additionally, scalability reactions transformation chiral intermediates into valuable structures emphasize synthetic practical importance strategy.

Язык: Английский

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Organocatalytic Synthesis of Spiro-Bridged Heterocyclic Compounds via a Chemoselective Vinylogous Michael/Cyclization/Rearrangement Sequence

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

Опубликована: Май 15, 2025

An organocatalytic cascade reaction of 2-ethylidene 1,3-indandiones and isatylidene-malononitriles has been achieved using quinine as the catalyst. The unexpected vinylogous Michael addition at β position isatylidene-malononitriles, followed by aldol cyclization, 1,2-addition alkoxide to nitrile, [1,3]-O-to-N rearrangement, leads generation unique spiro-bridged heterocyclic compounds containing amide, indanone, oxindole moieties in good excellent yields with high diastereoselectivity.

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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New Synthetic Approaches for the Construction of Enantioenriched Molecules Bearing Quaternary Stereocenters

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(21), С. 4294 - 4322

Опубликована: Авг. 17, 2024

Abstract Optically active molecule architectures stand as an important class of organic compounds and occupy a key role in academic industrial communities. Particularly, the molecules bearing quaternary carbon are vital importance because its favorable conformation valuable three‐dimensional molecules, which frequently play broad spectrum functional materials, pharmaceutical relevant natural agrochemicals. Over past few decades, large number synthetic strategies for enantioselective construction with chiral centers have been focus research initiatives. In this review, state‐of‐the‐art toward synthesis enantioenriched stereocenters summarized, could be segmented into four categories: 1) Construction optically by addition to prochiral sp 2 carbon; 2) all‐carbon via substitution at non‐chiral tetra‐substituted 3) kinetic resolution; 4) desymmetrization reactions.

Язык: Английский

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Lewis Base Promoted [4+2] Annulation of o‐Acylamino‐Aryl Morita‐Baylis‐Hillman Carbonates With Isatylidene Malononitriles: Facile Access to Spiro[Indolin‐3,2′‐Quinoline] Frameworks

Journal of Heterocyclic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Окт. 10, 2024

ABSTRACT A novel [4+2] annulation reaction between o ‐acylamino‐aryl MBH carbonates and isatylidene malononitriles has been successfully developed. This methodology exhibits excellent substrate tolerance, affording a series of spiro[indolin‐3,2′‐quinoline] framework compounds with yields up to 98%. The scalability the is also noteworthy, as evidenced by 95% yield final product upon 50‐fold scale‐up.

Язык: Английский

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Controllable Synthesis of N- and O-Containing Heterocycles via Formal [3 + 2] and [5 + 2] Cyclizations

Organic Letters, Год журнала: 2023, Номер 26(1), С. 6 - 11

Опубликована: Дек. 29, 2023

The controllable synthesis of spirooxindole–dihydrofurans and spirooxindole–benzazepines was developed through formal [3 + 2] [5 cyclization reactions from 2-(2-oxoindolin-3-yl)malononitriles ortho-aminobenzaldehydes, respectively. A variety spirooxindole-benzazepines were facilely constructed via a furan ring-open-involved hydride transfer/cyclization process. It is noteworthy that the application hydride-transfer-involved strategy for construction spirobenzazepines unprecedented. In addition, spiro N- O-containing heterocycles highly functionalized by amino, amide, cyano groups, which conducive to late-stage functionalization.

Язык: Английский

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The Asymmetric Synthesis of Polycyclic Tetrahydroxanthone via the Cascade Reaction of Alkene‐Substituted 1,3‐diketones and Alkenyloxindoles

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(8), С. 1888 - 1892

Опубликована: Фев. 26, 2024

Abstract Enantioselective access to polycyclic tetrahydroxanthone compounds was achieved through an organocatalyzed cascade reaction of alkene‐substituted 1,3‐diketones and alkenyloxindoles, using quinine‐derived squaramide as efficient catalyst. It afforded a variety optically active spirooxindole‐based tetrahydroxanthones with 18–94% yields, >19:1 dr, 86–99% ee.

Язык: Английский

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Organocatalyst as a synthetic gadget for pharmaceutically potent molecules

Arabian Journal of Chemistry, Год журнала: 2024, Номер 17(12), С. 106027 - 106027

Опубликована: Окт. 22, 2024

Язык: Английский

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Diastereoselective Construction of Spirocyclic Isobenzofurans via a Tandem Michael Addition/5-Exo-dig Cyclization Reaction

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(22), С. 16613 - 16621

Опубликована: Окт. 31, 2024

A practical approach for rapid and efficient access to spirocyclic isobenzofurans is described. The reaction proceeds through the cycloaddition of 1,6-ynenone derivatives 4-nitro-1,3-diarylbutan-1-ones, promoted by Cs

Язык: Английский

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