Synthesis of 2,4-Dicyanoalkylated Benzoxazines through the Radical-Mediated Cascade Cyclization of Isocyanides with AIBN under Metal- and Additive-Free Conditions

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(6), С. 3970 - 3976

Опубликована: Фев. 29, 2024

A general and novel method for the radical cascade cyclization of aryl isocyanides with AIBN has been described. This strategy provides straightforward access to various 2,4-dicyanoalkylated benzoxazines in moderate good yields under metal- additive-free conditions. The reaction can apply a gram scale tolerate diverse functional groups. 2,4-Dicyanoalkylated benzoxazine derivatives feature large Stokes shift intramolecular charge transfer properties.

Язык: Английский

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Regio- and Chemoselective Access to Dihydrothiophenes and Thiophenes via Halogenation/Intramolecular C(sp²)–H Thienation of α-Allyl Dithioesters at Room Temperature

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(21), С. 13935 - 13944

Опубликована: Окт. 7, 2022

An operationally simple, practical, and efficient cascade approach employing α-allyl dithioesters NBS/NIS has been achieved to access a series of dihydrothiophenes thiophenes containing diverse functional groups different electronic steric natures in good excellent yields at room temperature open air. The reaction proceeds via the electrophilic addition halogen source (NBS/NIS) an allylic double bond, followed by intramolecular regio- chemoselective S-cyclization. This protocol avoids potential toxicity tedious work-up conditions, features easy synthesis from readily available starting materials under catalyst-free conditions. Furthermore, 4,5-dihydrothiophenes were aromatized treatment with KOH DMF temperature. A probable mechanism for formation suggested. Notably, large-scale experiment transformations products indicated utility this compared competing processes thiophenes.

Язык: Английский

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Synthesis of Polysubstituted 2,3-Dihydropyridin-4(1H)-one in Water

Chinese Journal of Organic Chemistry, Год журнала: 2023, Номер 43(2), С. 742 - 742

Опубликована: Янв. 1, 2023

For the first time, aqueous [5C＋1N] annulation of α-alkenoyl ketene dithioacetals and amines for synthesis polysubstituted 2,3-dihydropyridin-4(1H)-ones was developed.In boiling water, (E)-2-(bis(ethylthio)methylene)-3-oxo-N,5-diarylpent-4-enamides 1 organic 2 smoothly occurred, 3 obtained in moderate yields.

Язык: Английский

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Radical Cyclization of N-Methacryloyl-2-arylbenzoimidazoles with Nitriles, Ketones, and tert-Butyl Nitrite under Mild Conditions

Synthesis, Год журнала: 2022, Номер 54(23), С. 5233 - 5244

Опубликована: Июль 3, 2022

Abstract A method for radical cyclization of N-methacryloyl-2-arylbenzoimidazoles with nitriles, ketones, and tert-butyl nitrite (TBN) the preparation benzimidazo[2,1-a]isoquinolin-6(5H)-ones advantage mild reaction conditions, excellent functional group compatibility, broad substrate scope is reported. The present strategy has favorable characteristics: (1) use cheap metal catalysis; (2) N-radical-initiated N-methacryloyl-2-arylbenzoimidazoles; (3) rare example C(sp3)–H functionalization in this cyclization.

Язык: Английский

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Metal‐free Radical Cyclization of Olefinic 1,3‐Dicarbonyls and Olefinic Amides with Nitrile C(sp³)−H Bonds in Aqueous Media

Asian Journal of Organic Chemistry, Год журнала: 2021, Номер 10(12), С. 3380 - 3383

Опубликована: Окт. 12, 2021

Abstract A radical cyclization of olefinic 1,3‐dicarbonyls and amides with nitrile C(sp 3 )−H bonds for the preparation valuable 2,3‐dihydrofurans benzoxazines have been developed. This protocol can be conducted at metal‐ base‐free conditions in aqueous media moderate to good yields. Moreover, practicality this strategy is further highlighted by gram‐scale reactions. The mechanistic investigation reveals that transformation initiated in‐situ formed cyanomethyl radical.

Язык: Английский

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Synthesis of gem-dibromo 1,3-oxazines by NBS-mediated electrophilic cyclization of propargylic amides

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(22), С. 4578 - 4582

Опубликована: Янв. 1, 2023

We present a highly efficient and practical method for synthesizing gem-dibromo 1,3-oxazines through 6-endo-dig cyclization of propargylic amides, using N-bromosuccinimide (NBS) as an electrophilic source. The metal-free reaction can be conducted under mild conditions with good functional group compatibility, delivering excellent yields the desired products. Mechanistic studies suggest that proceeds via double attack by NBS on amide substrate.

Язык: Английский

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Iodocyclization of olefinic amides with acetoxybenziodoxolone and NaI toward 4-iodomethylated benzoxazines

Mendeleev Communications, Год журнала: 2024, Номер 34(4), С. 566 - 568

Опубликована: Июль 1, 2024

Язык: Английский

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Dicarbonyl compounds in the synthesis of heterocycles under green conditions

Physical Sciences Reviews, Год журнала: 2022, Номер 8(9), С. 2725 - 2773

Опубликована: Янв. 8, 2022

Abstract Carbon–carbon and carbon-heteroatom bond forming reactions are strategically employed for the generation of a variety heterocyclic systems. This class compounds represents most general structural unit, present in many natural compounds. They recognized their valuable biologically properties wide range applications medicinal, pharmaceutical, other related fields chemistry. is an updated review on use dicarbonyl under environmentally friendly conditions to access series structures, e.g., quinoxaline, quinazolinones, benzochalcogenazoles, indoles, among others. Synthetic protocols involving copper-catalyzed, multicomponent cascade reactions, decarboxylative cyclization, recycling CO 2 , electrochemical approaches presented discussed.

Язык: Английский

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Electrophilic Halogen Reagents-mediated Halogenation: Synthesis of Halogenated Dihydro-1,3-oxazine Derivatives

Chemical Research in Chinese Universities, Год журнала: 2022, Номер 39(6), С. 933 - 947

Опубликована: Ноя. 21, 2022

Язык: Английский

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