N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of 5-Aminopyrazoles with Enals: Enantioselective Synthesis of Pyrazolo[3,4-b]pyridones

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(23), С. 16621 - 16632

Опубликована: Ноя. 15, 2023

An enantioselective construction of pyrazolo[3,4-b]pyridones was achieved via N-heterocyclic carbene-catalyzed [3 + 3] annulation enals with 5-aminopyrazoles. This protocol not only offers a highly efficient synthetic approach for the preparation various substituted but also provides an effective method rapid synthesis enantiopure spirooxindone derivatives.

Язык: Английский

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Synthesis of β‐Hydroxyselenides via Electrochemical Hydroxyselenenylation of Alkenes with Diselenides and H₂O

ChemistrySelect, Год журнала: 2024, Номер 9(5)

Опубликована: Фев. 2, 2024

Abstract A practical electrochemical method for the synthesis of β‐hydroxyselenides has been developed under an external oxidant‐free condition at room temperature air from alkenes with diselenides and H 2 O. radical mechanism is proposed this transformation gram‐scale reactions demonstrate practicability reaction.

Язык: Английский

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Synthesis of Highly Fluorescent Thiazole Fused Benzo[a] Carbazoles by Sunlight Driven Photocyclization of Indolylthiazoles

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

Опубликована: Ноя. 19, 2024

Abstract Herein we report for the first time a sunlight‐driven, irreversible photocyclization reaction of indole‐linked trisubstituted thiazoles, synthesis highly fluorescent thiazole‐fused benzo[ ]carbazoles using mixture solvents (CH 3 CN: DMSO; : 1). Ring opening indole moiety was observed in case thiazole derivatives having 2‐methyl substituents. Under similar conditions, thiazoles cyclic 1,3‐dicarbonyls place also worked. This provides products two medicinally important moieties and benzocarbazoles. We have studied photophysical properties all found that most synthesized very good fluorescence quantum yields.

Язык: Английский

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Enantioselective Synthesis of Dihydropyrazolo[3,4‐b]pyridin‐6‐ones via N‐Heterocyclic Carbene Catalyzed [3+3] Cycloaddition of α‐Bromoenals with 5‐Aminopyrazoles

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(4), С. 490 - 495

Опубликована: Янв. 24, 2023

Abstract An N‐heterocyclic carbene (NHC) catalyzed asymmetric [3+3] annulation of α ‐bromoenals with 5‐aminopyrazoles is described. Using the established methodology, a structurally diverse set high value dihydropyrazolo[3,4‐ b ]pyridine‐6‐ones were efficiently constructed in yields (up to 99%) excellent enantioselectivities >99%). The easily available starting materials, broad substrate scope, mild reaction conditions, yield and enantioselectivity make this strategy attractive for construction pyrazolo‐fused pyridone derivatives. magnified image

Язык: Английский

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Synthesis and Application Dichalcogenides as Radical Reagents with Photochemical Technology

Molecules, Год журнала: 2023, Номер 28(4), С. 1998 - 1998

Опубликована: Фев. 20, 2023

Dichalcogenides (disulfides and diselenides), as reactants for organic transformations, are important widely used because of their potential to react with nucleophiles, electrophilic reagents, radical precursors. In recent years, in combination photochemical technology, the application dichalcogenides stable reagents has opened up a new route synthesis various sulfur- selenium-containing compounds. this paper, synthetic strategies disulfides diselenides applications technology reviewed: (i) Cyclization alkenes alkynes; (ii) direct selenylation/sulfuration C−H/C−C/C−N bonds; (iii) visible-light-enabled seleno- sulfur-bifunctionalization alkenes/alkynes; (iv) Direct construction C(sp)–S bond. addition, scopes, limitations, mechanisms some reactions also described.

Язык: Английский

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Catalyst- and metal-free C(sp2)–H bond selenylation of (N-hetero)-arenes using diselenides and trichloroisocyanuric acid at room temperature

Scientific Reports, Год журнала: 2023, Номер 13(1)

Опубликована: Авг. 31, 2023

In this paper, we report an eco-friendly approach for the C(sp2)-H bond selenylation of imidazopyridines and other N-heteroarenes as well simple arenes at ambient temperature. This new protocol consists reaction between (N-hetero)-arenes diorganyl-diselenides trichloroisocyanuric acid (TCCA)-ethanol reagent system. a short time, desired selenylated products were obtained regioselectively in good yields, with tolerance wide range functional groups.

Язык: Английский

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Dihydroazolopyrimidines: Past, Present and Perspectives in Synthesis, Green Chemistry and Drug Discovery

The Chemical Record, Год журнала: 2023, Номер 24(2)

Опубликована: Сен. 5, 2023

Dihydroazolopyrimidines are an important class of heterocycles that isosteric to natural purines and therefore great interest primarily as drug-like molecules. In contrast the heteroaromatic analogs, synthetic approaches these compounds were developed much later, their chemical properties biological activity have not been studied in detail until recently. review, different ways build dihydroazolopyrimidine systems from building blocks described - via initial formation a partially hydrogenated pyrimidine ring or azole ring, well one-pot assembly azine fragments. Special attention is given modern approaches: multicomponent reactions, green chemistry, use non-classical activation methods. Information on dihydroazolopyrimidines prospects for design drugs various profiles also summarized this review.

Язык: Английский

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Visible light induced regioselective C-3 thiocyanation of imidazoheterocycles through naphthalimide dye based photoredox catalysis

Organic & Biomolecular Chemistry, Год журнала: 2023, Номер 21(42), С. 8471 - 8476

Опубликована: Янв. 1, 2023

A visible light induced C-3 thiocyanation of imidazo[1,2-a]pyridines by using a naphthalimide based photoredox catalyst has been reported. Tolerance electron withdrawing and donating groups at different positions the imidazo[1,2-a]pyridine ring led to wide substrate accessibility this method. This methodology is further reproducible with other heterocycles like benzo[d]imidazo[2,1-b]thiazoles, indoles, azaindoles, anilines.

Язык: Английский

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The O₂-Mediated Cross-Dehydrogenative Coupling: Rose Bengal-Catalyzed Direct Oxidative α-Acyloxylation of Ketones

Organic Letters, Год журнала: 2023, Номер 25(26), С. 4918 - 4922

Опубликована: Июнь 28, 2023

A general and facile approach for the direct oxidative α-acyloxylation of ketones using molecular oxygen as oxidant is developed. This method avoids use excessive peroxides expensive metal catalysts, affording a variety α-acyloxylated in satisfactory yields. Experimental studies indicate that reaction proceeds via radical pathway. Additionally, α-hydroxy could be obtained by changing solvent.

Язык: Английский

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Photocatalyst-Free Visible-Light-Promoted C–H Selenylation of Pyrazolo[1,5-a]pyrimidines

Synthesis, Год журнала: 2023, Номер 55(21), С. 3693 - 3699

Опубликована: Июль 6, 2023

Abstract A new method has been developed for the C–H selenyl­ation of pyrazolo[1,5-a]pyrimidine derivatives under irradiation visible light. This photocatalyst-free strategy is applicable to a wide range pyrazolo[1,5-a]pyrimidines with broad functionalities. The salient features are mild reaction conditions, use bench-stable oxidant, high regioselectivity, and scalability.

Язык: Английский

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