Base-Promoted [4 + 1 + 1] Multicomponent Tandem Cycloaddition of Ortho-Substituted Nitroarenes, Aldehydes, and Ammonium Salts To Access 2,4-Substituted Quinazoline Frameworks

The Journal of Organic Chemistry, Год журнала: 2025, Номер 90(5), С. 1982 - 1995

Опубликована: Янв. 23, 2025

We report a base-promoted, metal-free multicomponent tandem reaction, involving [4 + 1 1] cycloaddition process between ortho-substituted nitroarenes, aldehydes, and ammonium salts. Modifying the substituents on nitroaromatic compounds effectively provides structurally diverse 2-substituted 4-alkenylquinazolines with good to excellent yields (77%-90% quinazoline 51 examples) high tolerance for various inorganic salts (13 examples, such as NH3·H2O, NH4Cl, NH4HF2). A new method constructing 2,4-substituted selectivity from simple nitrogen source was developed, reaction can be scaled up gram scale. Additionally, this also facilitates preparation of organic molecules photophysical properties, offering insights into further transformation quinazolines.

Язык: Английский

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N-Heterocyclic Carbene-Catalyzed [4 + 2] Annulation of Enolizable Thioesters for the Synthesis of 2-Pyrones

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

Опубликована: Апрель 23, 2025

An N-heterocyclic carbene (NHC)-catalyzed [4 + 2] annulation enables the direct synthesis of 2-pyrones from α-chlorothioesters and β,γ-unsaturated α-keto esters or chalcones. The method utilizes NHC-activated to generate key intermediates for 2-pyrone formation with high functional group tolerance. Moreover, were transformed into polysubstituted benzene naphthalene derivatives, showcasing their synthetic value.

Язык: Английский

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Domino Sequence of Ketimization and Electrophilic Amination for an Inverse Aza Intramolecular Morita–Baylis–Hillman Adduct

The Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Окт. 3, 2024

Morita-Baylis-Hillman (MBH) reaction, typically catalyzed by a Lewis base, is popular and useful method for C-C bond formation. Unfortunately, it limited slow reaction rate has sensitivity toward steric electronic parameters. Despite tremendous efforts, the versatility of keeps quest open new mechanistic catalytic pathways. Here, we have reported Bro̷nsted acid-catalyzed, electrophilic amination (Umpolung imine) as an inverse Aza Intramolecular MBH adduct in form 2-acylindole. Umpolung imine with nitrogen acting center been achieved. Interestingly, was also shown to occur under catalyst-free conditions also. The expected products ketimine formation, 6π electrocyclization, or quinoline formation were least/not observed. A large number examples demonstrated strength. β-aryl-substituted acrylate acrylamide (cinnamates cinnamides), which are extremely sluggish conventional chemistry, highlights developed methodology. annulated product exhibited keto-enol tautomerism, proven

Язык: Английский

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Rhodaelectro-Catalyzed Synthesis of Pyrano[3,4-b]indol-1(9H)-ones via the Double Dehydrogenative Heck Reaction between Indole-2-carboxylic Acids and Alkenes

The Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 12, 2024

A rhodaelectro-catalyzed double dehydrogenative Heck reaction of indole-2-carboxylic acids with alkenes has been developed for the synthesis pyrano[3,4-

Язык: Английский

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Copper-Catalyzed Cascade Cyclization of 2-Nitrochalcones with NH-Heterocycles

The Journal of Organic Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 19, 2024

We developed a method for allowing cascade cyclization of 2-nitrochalcones with pyrazoles, imidazole, and indazole in the presence CuI catalyst, DBU base, THF solvent. The conditions were tolerant an array useful functionalities including ester, nitro, cyano, halogen groups. A mechanistic consideration was also provided, as H2O2 presumably byproduct. Our appears to be rare example directly prepare C3-heterocyclic unprotected indoles.

Язык: Английский

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Substrate-induced Dual Utilization Cascade Reaction of N-alkyl Anilines: Highly Site-selective Sustainable Synthesis of Chromeno[4,3-b]quinolin-6-ones

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 29, 2024

A substrate-induced cleavage and reorganization cascade reaction of N -alkyl anilines as a carbon source the waste group into chromeno[4,3- b ]quinolin-6-ones.

Язык: Английский

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