Acetoxy allenoates as emerging synthons in annulation/cycloaddition reactions

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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NHC-catalyzed formal [3 + 3] annulations of δ-acetoxy allenoates for the synthesis of 4H-pyran derivatives

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(28), P. 5775 - 5783

Published: Jan. 1, 2023

Herein, an N-heterocyclic carbene (NHC) catalyzed formal [3 + 3] annulation of δ-acetoxy allenoates with 1C,3O-bisnucleophiles for the construction 4H-(fused)pyrans has been developed. This protocol provides a facile method to synthesize highly functionalized 4H-pyrans and broad substrate scope (30 examples, up 77% yield).

Language: Английский

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Recent Advances in Lewis Base‐Catalysed Chemo‐, Diastereo‐ and Enantiodivergent Reactions of Electron‐Deficient Olefins and Alkynes

The Chemical Record, Journal Year: 2021, Volume and Issue: 22(4)

Published: Dec. 27, 2021

Abstract Lewis base catalysis provides powerful synthetic strategies for the selective construction of carbon‐carbon and carbon‐heteroatom bonds. Thus continuous efforts have been deployed to develop effective methodologies involving catalysis. The nucleophilicity steric hindrance catalyst often plays a major role in catalytic reactivity selectivity reaction. In past decades, tremendous progress has made divergent valuable motifs under this review, we provide comprehensive updated summary base‐catalysed chemo‐, diastereo‐ enantiodivergent reaction, as well related mechanism will be highlighted detail.

Language: 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, Journal Year: 2024, Volume and Issue: 56(12), P. 1912 - 1922

Published: Feb. 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.

Language: Английский

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DMAP Catalyzed Ring-Opening/Cycloaddition of Vinyl Oxiranes with Activated Ketone Compounds to Construct the 1,3-Dioxolane Skeletons

Organic Letters, Journal Year: 2024, Volume and Issue: 26(43), P. 9322 - 9327

Published: Oct. 24, 2024

The present work develops a DMAP-catalyzed [3 + 2] cycloaddition of vinyl oxiranes with activated ketone compounds, affording dioxolane derivatives moderate to excellent yields. This approach represents the first Lewis base (LB)-catalyzed ring-opening reaction epoxides, simultaneously providing rare oxygen-containing active intermediate in this field. gram-scale preparation and facile derivatization cycloadduct highlight significant synthetic potential strategy.

Language: Английский

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Diastereoselective Double Annulation of Allenoates with Povarov Adducts: Modular Synthesis of Multisubstituted Pyrroloquinolines

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(22), P. 16838 - 16849

Published: Nov. 6, 2024

Herein, we report an atom-economical, one-pot, four-component, diastereoselective double-annulation reaction to construct polyfused pyrroloquinolines. This highlights the cyclization of in situ

Language: Английский

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Phosphine-Catalyzed [3+2] Annulation of Hepta-2,3,5-trienedioates with Alkenes for the Construction of Exocyclic Olefinic Cyclopentenes

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(14), P. 10212 - 10222

Published: July 11, 2023

Hepta-2,3,5-trienedioates 1 have been employed as substrates to explore Lewis base-catalyzed annulation reactions. This leads the discovery of a phosphine-catalyzed [3+2] with electron-deficient alkenes for construction exocyclic olefinic cyclopentenes in good yields and moderate E:Z ratios under mild conditions. The is believed proceed tandem cyclization double bond migration which ε-ester crucial both processes. reaction also showcases substrate-controlled divergent reactivity compared that previous report.

Language: Английский

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Chemodivergent annulations of allenyl imides and β,γ-enones switched by nucleophilic phosphine and amine catalysts

Chinese Chemical Letters, Journal Year: 2023, Volume and Issue: 35(1), P. 108777 - 108777

Published: July 6, 2023

Language: Английский

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Cooperative palladium-catalyzed P(NEt₂)₃-mediated (4 + 1) annulation of isatins with 2 hydroxymethylallylcarbonates

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(12), P. 3215 - 3221

Published: Jan. 1, 2022

Cooperative palladium-catalyzed and P(NEt 2 ) 3 -mediated (4 + 1) annulations are developed, leading to a big library of spirooxindole derivatives in high structural diversity.

Language: 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, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 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).

Language: Английский

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