δ-Acetoxy Allenoate as a 5C-Synthon in Domino-Annulation with Sulfamidate Imines: Ready Access to Coumarins

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(17), С. 12432 - 12444

Опубликована: Авг. 21, 2023

A DMAP-catalyzed sequential benzannulation and lactonization strategy in which δ-acetoxy allenoate functions as a 5C-synthon its reaction with cyclic sulfamidate imines is reported. This platform delivers π-extended coumarin frameworks under metal-free conditions via allylic elimination followed by Mannich coupling, proton shifts, C-N bond cleavage, key steps. The driving force for this domino the formation of diene-ammonium intermediate O-S cleavage. ESI-HRMS has been useful gaining insights into pathway.

Язык: Английский

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Acetoxy allenoates as emerging synthons in annulation/cycloaddition reactions

Chemical Communications, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

The emergence of acetoxy allenoates as versatile synthons to generate a plethora annulation/cycloaddition products via electrophilic diene–phosphonium/ammonium intermediates is highlighted in this feature article.

Язык: Английский

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Divergent Reactivity of δ-Acetoxy Allenoates with 1,3-Bisnucleo­philes: Synthesis of Multisubstituted Pyran, Dihydropyran, and 3-Vinylpent-2-enedioate Scaffolds

Synthesis, Год журнала: 2024, Номер 56(12), С. 1912 - 1922

Опубликована: Фев. 20, 2024

Abstract Base-dependent synthesis of tetrasubstituted pyrans or 3,4-dihydropyrans using δ-acetoxy allenoates and enolizable carbonyls like cyclohexan-1,3-dione ethyl benzoylacetate is reported. Thus, the use DMAP as an organocatalytic base gives while DBU affords isomeric 3,4-dihydropyrans. The reaction with mediated by KO t Bu furnishes diethyl 3-vinylpent-2-enedioates.

Язык: Английский

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DBU catalyzed (3 + 3) annulation of β′ and δ-acetoxy allenoates with benzo-oxathiin-dioxide and phenylthiazolone: Synthesis of pyrano-oxathiines and pyrano-thiazoles

Journal of Chemical Sciences, Год журнала: 2024, Номер 136(4)

Опубликована: Окт. 4, 2024

Язык: Английский

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Synthesis of Isoxazol-5(2H)-one Derivatives via (^tBuO)₂Mg Promoted [3 + 2] Annulations of δ-Acetoxy Allenoates with Hydroxylamine

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(11), С. 8291 - 8298

Опубликована: Май 28, 2024

Herein, an efficient (

Язык: Английский

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Phosphine vs DBU-Catalyzed Annulation Reactions of β′-Acetoxy Allenoates with Acyl-Tethered Benzothiazole Bisnucleophiles: (4 + 3) or (4 + 1) vs (3 + 3) Annulation

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(15), С. 10816 - 10830

Опубликована: Июль 15, 2024

Dearomative annulation reaction of acyl-tethered benzothiazole bisnucleophiles with β'-acetoxy allenoates by switching the Lewis base is developed. The DBU-catalyzed gives benzothiazole-fused 1,4-dihydropyridine carboxylates (3 + 3) chemoselectively. By contrast, PR

Язык: Английский

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Synthesis of Fused-Pyran Derivatives via a Base-Mediated Annulation of Bis-Allenoates Followed by Auto-Oxidation in Air

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер 22(32), С. 6543 - 6549

Опубликована: Янв. 1, 2024

We introduce, for the first time, an inorganic base-mediated cyclization and auto-oxidation of bisallenones/bisalkynones. This reaction is realized under mild conditions through precise control base atmosphere, providing a wide range structurally diverse fused-pyran derivatives with moderate to excellent yields. Utilizing KOH as initiator nitrogen series novel cyclohexane-fused pyran was obtained primary product. In contrast, aerobic Na

Язык: Английский

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NHC‐Catalyzed [3+3] cycloaddition of 2‐(acetoxymethyl)buta‐2,3‐dienoates with 1C,3O‐bisnucleophiles

Asian Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Окт. 9, 2024

Abstract Diverse transformations of allenoates catalyzed by Lewis bases have emerged as a powerful platform for generating new chemical entities in organic synthesis. Herein, an N ‐heterocyclic carbene (NHC) [3+3] cyclization 2‐(acetoxymethyl)buta‐2,3‐dienoates with 1 C,3O‐bisnucleophiles has been developed. This approach provides facile method to synthesize highly functionalized 4 H ‐pyran derivatives broad substrate scope (31 examples, up 83 % yield).

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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