Synthetic Strategies Toward 2H‐, 4H‐Pyrans, and Pyranones: Recent Advances DOI

Subhasis Samai,

Sanghamitra Atta,

Maya Shankar Singh

et al.

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(21)

Published: May 30, 2025

Abstract Pyrans are a class of six‐membered heterocyclic rings containing five carbon atoms and one oxygen atom. They non‐aromatic in nature, bearing two double bonds the ring. The bond position distinguishes pyran isomers, namely, 2 H ‐pyran 4 ‐pyran. When saturated sp 3 is located next to an atom, it known as ‐pyran, when at 4‐position with respect In 1962, by thermal breakdown 2‐acetoxy‐3,4‐dihydro‐2 ‐pyrans were produced for first time, their characteristics explored. Numerous synthetic methods have been disclosed over time owing broad applications diverse fields, mainly drug design, pharmaceuticals, material science. this review, we highlight recent advancements toward substituted 4‐pyranone, 2‐pyranones, focusing on reports published from 2019 till date, which play important roles both organic synthesis types functional molecules.

Language: Английский

Sulfinate-Promoted Defluorinative Cyclization of Polyfluoroalkyl Tetralones Enabled by Photocatalysis DOI

Ming-Yao Tang,

M Kellis, Xiaoxiao Sun

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 3, 2025

A Ru-catalyzed defluorinative cyclization of polyfluoroalkyl tetralones has been developed under visible-light irradiation for the precise assembly γ-pyrones featuring α-perfluoroalkyl and β-fluorine substituents. Selective functionalization five C(sp3)–F bonds at three carbon sites on perfluoroalkyl chain provides a new mode utilizing polyfluorides as versatile synthons to access difficult-to-obtain heterocyclic scaffolds. Moreover, sulfinate salt serves dual roles an oxygen source creating carbonyl group defluorinating promoter.

Language: Английский

Citations

3
Tunable Key [3 + 2] and [2 + 1] Cycloaddition of Enaminones and α-Diazo Compounds for the Synthesis of Isomeric Isoxazoles: Metal-Controlled Selectivity DOI
Wenli Song, Yunyun Liu, Nan Yan

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(12), P. 2139 - 2144

Published: March 22, 2023

The three-component reactions of enaminones, α-diazo esters/ketones, and t-butyl nitrite (TBN) for the switchable synthesis isomeric isoxazoles have been realized. catalysis with Cu(II) salt provides 3,4-disubsituted via [3 + 2] cycloaddition. On other hand, Ag(I) identical substrates leads to reversed C3 C4 substitution based on a key [2 1]

Language: Английский

Citations

41
Synthesis of Tetrahydro-indolones through Rh(III)-Catalyzed [3 + 2] Annulation of Enaminones with Iodonium Ylides DOI

Mingshuai Zhang,

Longkun Chen,

Haifeng Sun

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(40), P. 7298 - 7303

Published: Oct. 3, 2023

An unprecedented protocol for a Rh(III)-catalyzed [3 + 2] annulation from simple and readily available enaminones iodonium ylides has been developed. The novel strategy allows access to new class of structurally diverse tetrahydro-indolones with high efficiency broad substrate scope. In addition, this transformation represents the first example selective alkenyl C–H bond functionalization enaminones. Finally, potential applications are demonstrated through gram-scale reaction late-stage modification.

Language: Английский

Citations

38
Three-component synthesis ofN-naphthyl pyrazolesviaRh(iii)-catalyzed cascade pyrazole annulation and Satoh–Miura benzannulation DOI

Demao Chen,

Liyun Zhou,

Yunyun Liu

et al.

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(27), P. 4036 - 4039

Published: Jan. 1, 2023

The synthesis of N-naphthyl pyrazoles has been realized by the direct three-component reactions enaminones, aryl hydrazine hydrochlorides and internal alkynes via Rh(III) catalysis. synthetic employing simple substrates lead to simultaneous construction dual cyclic moieties, including a pyrazole ring phenyl ring, sequential formation two C-N three C-C bonds.

Language: Английский

Citations

34
Rh(III)-Catalyzed [3 + 2] Annulation/Pinacol Rearrangement Reaction of Enaminones with Iodonium Ylides: Direct Synthesis of 2-Spirocyclo-pyrrol-3-ones DOI

Mingshuai Zhang,

Longkun Chen,

Haifeng Sun

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(39), P. 7214 - 7219

Published: Sept. 26, 2023

A novel Rh(III)-catalyzed cascade alkenyl C-H activation/[3 + 2] annulation/pinacol rearrangement reaction of enaminones with iodonium ylides has been developed. This methodology provides a new and straightforward synthetic strategy to afford highly functionalized 2-spirocyclo-pyrrol-3-ones in satisfactory yield from readily available starting materials under mild conditions. Moreover, gram-scale reactions further derivatization experiments are implemented demonstrate the potential utility this developed approach.

Language: Английский

Citations

33
Recent advances in transition metal-catalyzed transformations in N,N-disubstituted enaminones DOI
Leiqing Fu, Jie‐Ping Wan

Tetrahedron Letters, Journal Year: 2023, Volume and Issue: 130, P. 154766 - 154766

Published: Sept. 26, 2023

Language: Английский

Citations

29
Rh-Catalyzed and Self-Directed Aromatic C–H Activation of Enaminones to Divergent Alkenylated and Annulated Compounds DOI

Demao Chen,

Jie‐Ping Wan, Yunyun Liu

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 27, 2025

By means of simple Rh catalysis, the direct activation ortho-C-H bond in aryl enaminones has been realized with enaminone structure as a traceless directing fragment. The products resulting from C-H alkenylation and further annulation via intramolecular addition could be accessed depending upon alkenes. annulated used for easy synthesis valuable 2-aza-fluorenones one-pot operation by employing NH4OAc.

Language: Английский

Citations

2
Recent Advances in Electrochemical Cascade Cyclization Reactions DOI
Cai Zhang, Yunyun Liu,

Demao Chen

et al.

Synthesis, Journal Year: 2023, Volume and Issue: 55(18), P. 2911 - 2925

Published: Feb. 20, 2023

Abstract This review highlights recent progress in electrochemical cascade cyclization reactions for the synthesis of carbon rings and heterocycles, such as pyridines, quinolines, phenanthridines, cinnolines, 1,4-dihydroquinolines, oxindoles, imidazo[1,5-α]pyridines, imidazoles, etc. The works included herein are introduced two major sections heterocycle construction carbocycle reactions, covering reported from 2012 to 2022. 1 Introduction 2 Electrochemical Cascade Cyclization Synthesis Heterocycles 2.1 Pyridines, Quinolines, Phenanthridines, Cinnolines 2.2 1,4-Dihydroquinolines, Hexacyclic Sulfonamides, Thiazines 2.3 Hydroisoquinolinones Hydroquinolinones 2.4 Quinazolin-4(3H)-ones 2.5 4H-3,1-Benzoxazines 2.6 Oxindoles 2.7 Indolines Indoles 2.8 Imidazo[1,5-α]pyridines Imidazoles 2.9 Imidazolones, Imidazolidinones, Oxazolones, Oxazolidinones 2.10 Benzoxazoles, Oxazolines, Isoxazolines 2.11 Furans Dihydrofurans 2.12 Indolizines, Pyrazoles, Triazolium Inner Salts 2.13 Sulfonated Benzothiophenes, Thiazoles, Dihydrothiazoles, 1,3,4-Thiadiazoles 2.14 Lactones 3 Construction Carbocycles 3.1 Carbon Polycycles Spiroindenes 3.2 Difluoroacyl (Hetero)arenes Indenones 4 Conclusion

Language: Английский

Citations

23
Synthesis of homophthalimide spironaphthalenones through [5 + 1] spiroannulation of aryl/alkenyl enaminones with diazo homophthalimides DOI

Chun Xia Yang,

Xinying Zhang, Xuesen Fan

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(17), P. 4282 - 4288

Published: Jan. 1, 2023

Presented herein is a novel synthesis of homophthalimide spironaphthalenones from the cascade reaction enaminones with diazo homophthalimides.

Language: Английский

Citations

21
Copper‐Catalyzed Oxidative [1+2+1+2] Cascade Cyclization of N,N‐Dimethyl Enaminones with Benzylamines: A Facile Access to Functionalized 1,4‐Dihydropyridines DOI

Yulin Sun,

Zhangmengjie Chai,

Donghan Liu

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(28)

Published: Feb. 24, 2023

Using benzylamines as the C4 source of 1,4-dihydropyridines (1,4-DHPs), a Cu-catalyzed oxidative [1+2+1+2] cascade cyclization for synthesis 1,4-DHPs was firstly developed. A broad range easily available N,N-dimethyl enaminones and are employed smoothly to provide diverse with high efficiency. This method is performed by one-pot C(sp3 )-H bond functionalization/C(sp3 )-N cleavage/cyclization strategy form simultaneously two )-C(sp2 ) bonds, C(sp2 1,4-DHP ring.

Language: Английский

Citations

20