Pyridinium Ylide-Mediated Diastereoselective Synthesis of Spirocyclopropanyl-pyrazolones via Cascade Michael/Substitution Reaction

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(11), С. 8230 - 8242

Опубликована: Май 14, 2024

We have devised a highly diastereoselective formal [2 + 1] annulation reaction of arylidene/alkylidine-pyrazolones with in situ-generated supported as well standard pyridinium ylides to construct spirocyclopropanyl-pyrazolones. The cascade approach exhibits wide range functional group tolerance, gram-scale capability, and substrate versatility. A diverse spirocyclic cyclopropanes was synthesized extensively both mediators, the pyridine reused subsequent cycles. Density theory calculations confirmed formation spirocyclopropane lower energy pathway.

Язык: Английский

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Silver-Promoted (4 + 1) Annulation of Isocyanoacetates with Alkylpyridinium Salts: Divergent Regioselective Synthesis of 1,2-Disubstituted Indolizines

Organic Letters, Год журнала: 2021, Номер 23(19), С. 7555 - 7560

Опубликована: Сен. 15, 2021

An unprecedented silver-promoted regioselective (4 + 1) annulation of isocyanoacetates with pyridinium salts is reported. The established protocol provides controlled, facile, and modular access to a range synthetically useful N-fused heterocyclic scaffolds containing indolizines, pyrrolo[1,2-a]quinolines, pyrrolo[2,1-a]isoquinolines, 1H-imidazo[4,5-a]indolizin-2(3H)-ones. A mechanistic pathway involving nucleophilic addition/protonation/elimination/cycloisomerization proposed.

Язык: Английский

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Transition metal-free annulative vinylene transfer via the 1,3-dipolar reaction of N-ylides: access to benzo-fused indolizines

Organic & Biomolecular Chemistry, Год журнала: 2022, Номер 20(48), С. 9604 - 9608

Опубликована: Янв. 1, 2022

An efficient metal-free annulative vinylene transfer protocol for the synthesis of benzo-fused indolizines via 1,3-dipolar cycloadditions N-ylides with carbonate has been developed. Vinylene serves as an acetylene surrogate without any external oxidant involved. This transformation leads to direct construction versatile indolizine derivatives in moderate good yields.

Язык: Английский

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Synthesis of Functionalized Indolizines through 1,3-Dipolar Cycloaddition of Zwitterionic Ketenimines and Pyridinium Salts

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

Опубликована: Апрель 19, 2025

A straightforward and efficient strategy for the synthesis of fully functionalized indolizines has been developed through a transition metal- oxidant-free [3 + 2] cycloaddition reaction zwitterionic ketenimines pyridinium salts. This versatile method proceeds under mild conditions, affording in moderate to good yields. approach involves an intermolecular cycloaddition, followed by enamine/imine tautomerization aromatization. Notably, this demonstrates broad functional group compatibility allows facile scalability, making it valuable tool indolizine-based frameworks organic medicinal chemistry.

Язык: Английский

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Progress in N-α-C(sp³)—H Bond Functionalization for the Synthesis of N-Heterocycles

Chinese Journal of Organic Chemistry, Год журнала: 2025, Номер 45(4), С. 1047 - 1047

Опубликована: Янв. 1, 2025

Язык: Английский

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Formal (3 + 1 + 1) Carboannulation of Morita–Baylis–Hillman Carbonates with Pyridinium Ylides: Access to Spiro-Cyclopentadiene Oxindoles

Organic Letters, Год журнала: 2021, Номер 23(22), С. 8937 - 8941

Опубликована: Ноя. 9, 2021

An efficient formal (3 + 1 1) carboannulation strategy of Morita–Baylis–Hillman (MBH) carbonates with pyridinium ylides was developed for constructing diversely functionalized spiro-cyclopentadiene oxindoles. The reaction initiates an SN2′ olefination MBH ylides. in situ generated dienes then engage a challenging (4 ylide carboannulation, which has been rarely reported before. features broad substrate scope as well high chemo- and regioselectivity. products could be easily transformed into interesting spiro-cyclopenta[c]furan

Язык: Английский

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Copper‐Catalyzed [3+2] Annulation of Pyridinium Ylides with α‐CF₃ Ketones: Synthesis of Functionalized 2‐Fluoroindolizines

Asian Journal of Organic Chemistry, Год журнала: 2023, Номер 12(5)

Опубликована: Март 23, 2023

Abstract A copper‐catalyzed [3+2] annulation of the in situ generated pyridinium ylides with α‐CF 3 ketones was realized, which first acted as synthetic equivalents unstable fluoroalkynones. With this protocol, a series functionalized 2‐fluoroindolizines were afforded moderate to good yields under ambient conditions air oxidant.

Язык: Английский

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Oxidative [3+2] Annulation of Pyridinium Salts with gem‐Difluoroalkenes: Synthesis of 2‐Fluoroindolizines

Asian Journal of Organic Chemistry, Год журнала: 2021, Номер 10(7), С. 1679 - 1682

Опубликована: Апрель 9, 2021

Abstract An oxidative [3+2] annulation of pyridinium salts with gem ‐difluoroalkenes for the synthesis highly substituted 2‐fluoroindolizines has been developed. Using DBU as base, a broad range multisubstituted were prepared in good to excellent yields under mild conditions, and many useful functional groups can be tolerated.

Язык: Английский

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Dual role of BrCF₂CO₂Et: difluorocarbene-enabled access to α-trifluoromethyl ketones from sulfoxonium ylides

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(15), С. 3741 - 3745

Опубликована: Янв. 1, 2023

A transition metal and external fluorine anion-free method has been developed for the efficient trifluoromethylation of sulfoxonium ylides with BrCF 2 CO Et to afford α-trifluoromethyl ketones.

Язык: Английский

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Copper-Catalyzed Bisannulations of Malonate-Tethered O-Acyl Oximes with Pyridine, Pyrazine, Pyridazine, and Quinoline Derivatives for the Construction of Dihydroindolizine-Fused Pyrrolidinones and Analogues

Organic Letters, Год журнала: 2021, Номер 23(22), С. 8699 - 8704

Опубликована: Ноя. 1, 2021

A copper-catalyzed bisannulation reaction of malonate-tethered O-acyl oximes with pyridine, pyrazine, pyridazine, and quinoline derivatives has been developed for the concise synthesis structurally novel dihydroindolizine-fused pyrrolidinones their analogues. The present shows excellent regioselectivity stereoselectivity. Theoretical calculations reveal that coordination effect carbonyl group in nucleophilic substrate determines regioselectivity. Further functionalization generated pyrrolidinone could be easily realized through substitution, Michael addition, selective aminolysis, hydrolysis reactions.

Язык: Английский

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