Recent Strategies in the Nucleophilic Dearomatization of Pyridines, Quinolines, and Isoquinolines

Chemical Reviews, Год журнала: 2024, Номер 124(3), С. 1122 - 1246

Опубликована: Янв. 2, 2024

Dearomatization reactions have become fundamental chemical transformations in organic synthesis since they allow for the generation of three-dimensional complexity from two-dimensional precursors, bridging arene feedstocks with alicyclic structures. When those processes are applied to pyridines, quinolines, and isoquinolines, partially or fully saturated nitrogen heterocycles formed, which among most significant structural components pharmaceuticals natural products. The inherent challenge lies low reactivity heteroaromatic substrates, makes dearomatization process thermodynamically unfavorable. Usually, connecting event irreversible formation a strong C–C, C–H, C–heteroatom bond compensates energy required disrupt aromaticity. This aromaticity breakup normally results 1,2- 1,4-functionalization heterocycle. Moreover, combination these subsequent tandem stepwise protocols allows multiple heterocycle functionalizations, giving access complex molecular skeletons. aim this review, covers period 2016 2022, is update state art nucleophilic dearomatizations showing extraordinary ability dearomative methodology indicating their limitations future trends.

Язык: Английский

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Recent Advances in Metal‐Catalyzed C−H Bond Functionalization Reactions of Sulfoxonium Ylides

Asian Journal of Organic Chemistry, Год журнала: 2022, Номер 11(4)

Опубликована: Март 23, 2022

Abstract In recent years, the transition‐metal‐catalyzed functionalization reactions of sulfoxonium ylides have been explored extensively because their usefulness as carbene‐transfer agents, since they can produce metal carbenes through catalysis. Moreover, are safer and advantages simple handling good stability over other counterparts like diazo‐compounds. This review article attempts to highlight advances in metal‐catalyzed C−H ylides.

Язык: Английский

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Sigma-Bond Metathesis as an Unusual Asymmetric Induction Step in Rhodium-Catalyzed Enantiodivergent Synthesis of C–N Axially Chiral Biaryls

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(15), С. 8417 - 8429

Опубликована: Март 23, 2023

Mechanistic understanding of asymmetric induction plays a crucial role in designing new catalytic reactions. Reported herein is atroposelective access to C-N axially chiral isoquinolones via rhodium-catalyzed C-H activation N-alkoxy benzamides and annulation with imidoyl sulfoxonium ylides. The coupling system proceeded excellent functional group tolerance, different conditions were identified afford one or the other enantiomeric product each enantioselectivity for representative class ylide reagent, thus making both enantiomers readily available using same catalyst. Experimental computational studies revealed pathway alkylation enantio-determining formal nucleophilic substitution-C-N cyclization that mediated by rhodium catalyst σ-bond metathesis as mechanism. Computational indicated solvent-dependent enatiodivergence originated from levels neutral versus cationic species.

Язык: Английский

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Divergent Synthesis of Tetrasubstituted Phenols via [3 + 3] Cycloaddition Reaction of Vinyl Sulfoxonnium Ylides with Cyclopropenones

Organic Letters, Год журнала: 2023, Номер 25(23), С. 4286 - 4291

Опубликована: Июнь 2, 2023

Two categories of tetrasubstituted phenols were prepared via the cycloaddition reaction vinyl sulfoxonnium ylides with cyclopropenones in a switchable manner. Copper carbenoid was proposed as active intermediate process 2,3,4,5-tetrasubstituted formation, while 2,3,5,6-tetrasubstituted generated direct [3 + 3] annulation under metal-free conditions. Further synthetic applications also demonstrated.

Язык: Английский

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Hydroxyl-Directed Ru(II)-Catalyzed Synthesis of Fused Dihydrofurans Using 1,4-Dioxane and Sulfoxonium Ylides as Annulating Agents

Organic Letters, Год журнала: 2023, Номер 25(1), С. 215 - 219

Опубликована: Янв. 3, 2023

An unprecedented annulation reaction is developed for the synthesis of dihydrofuran-fused compounds. In this Ru-catalyzed hydroxyl-group-directed reaction, easily affordable sulfoxonium ylides and 1,4-dioxane were used as annulating partners. This first example use a methylene source to construct heterocyclic scaffold. A wide range dihydrofuran0fused coumarins naphthalenes synthesized using three-component reaction.

Язык: Английский

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Rhodium-Catalyzed N-Arylation of 2-Pyridones Enabled by 1,6-Acyl Migratory Rearrangement of 2-Oxypyridines

Organic Letters, Год журнала: 2023, Номер 25(11), С. 1974 - 1977

Опубликована: Март 15, 2023

An efficient rhodium-catalyzed dearomative rearrangement of 2-oxypyridines with quinone diazides has been developed for the direct synthesis N-arylated pyridones, in which a novel 1,6-O-to-O rather than 1,4-O-to-C acyl achieved under mild reaction conditions.

Язык: Английский

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Metal-free cascade O–H double insertion between I^(III)/S^(VI)-ylides, carboxylic acids, and alcohols: modular access to unsymmetrical α,α-O,O-substituted ketones

Organic Chemistry Frontiers, Год журнала: 2024, Номер 11(11), С. 3234 - 3241

Опубликована: Янв. 1, 2024

Herein, we present a cascade O–H double insertion reaction between I (III) /S (VI) -ylides, carboxylic acids, and alcohols under metal-free conditions, enabling the modular synthesis of unsymmetrical α,α- O , -substituted ketones.

Язык: Английский

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P(NMe₂)₃-Mediated Regioselective N-Alkylation of 2-Pyridones via Direct Deoxygenation of α-Keto Esters

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(5), С. 3657 - 3665

Опубликована: Фев. 17, 2024

A practical and regioselective direct N-alkylation of 2-pyridones is enabled by use α-keto esters in the P(NMe2)3-mediated deoxygenation process. The reaction proceeds under mild conditions to produce N-alkylated with high selectivity generality, protocol shown be applicable for scale-up synthesis, which makes it promising applications.

Язык: Английский

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Copper-Mediated Cyclization of Terminal Alkynes with CF₃-Imidoyl Sulfoxonium Ylides To Construct 5-Trifluoromethylpyrroles

Organic Letters, Год журнала: 2024, Номер 26(11), С. 2249 - 2254

Опубликована: Март 7, 2024

A copper-mediated [3 + 2] cyclization of CF3-imidoyl sulfoxonium ylides and terminal alkynes has been demonstrated. This work provides a practical approach for assembling 5-trifluoromethylpyrroles with the merits broad substrate scope, good functional tolerance, mild reaction conditions. Control experiments DFT studies indicate that this may involve addition π-bonds by copper-carbene radicals hydrogen migration.

Язык: Английский

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Copper-catalyzed P–H insertion reactions of sulfoxonium ylides

Organic & Biomolecular Chemistry, Год журнала: 2021, Номер 19(26), С. 5767 - 5771

Опубликована: Янв. 1, 2021

A copper-catalyzed P–H insertion reaction between sulfoxonium ylides and H-phosphorus oxides has been developed to synthesize α-phosphonyl carboxylate derivatives.

Язык: Английский

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