Merging Photoinduced Electron Transfer with Hydrogen Atom Transfer: Formal β-C(sp³)–H Pyridination of Carbonyls

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 9, 2025

In this study, a novel approach that combines photoinduced electron transfer (ET) with hydrogen atom (HAT) has been introduced for the selective β-C(sp3)–H pyridination of carbonyl compounds. This method is notable its absence transition metals and ability to function under benign reaction conditions, resulting in range pyridinated derivatives consistently moderate good yields. The significance technique further underscored by potential late-stage functionalization pharmaceutically significant molecules. Mechanistic investigations confirmed proceeds via radical-mediated pathway.

Language: Английский

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Multicomponent Tf₂O-Triggered Dearomative Triazinylmethylation of Isoquinolines Using Acetonitrile

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 13, 2025

A Tf2O-triggered dearomative triazinylmethylation of isoquinolines and other azaarenes utilizing acetonitrile as the nucleophile has been developed through a formal five-component reaction. This method showcases broad substrate scope exceptional functional group compatibility, presenting mild expedient synthetic approach. Kinetic studies, including kinetic isotope effect (KIE) Hammett analysis, indicate that activation by Tf2O constitutes rate-limiting step.

Language: Английский

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Visible-Light-Mediated Three-Component Alkene 1,2-Alkylpyridylation Reaction Using Alkylboronic Acids as Radical Precursors for the Synthesis of 4-Alkylpyridines

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 3, 2025

We report the photocatalyzed three-component alkene 1,2-alkylpyridylation reaction between alkylboronic acids, 4-cyanopyridine, and an olefin to achieve pyridination alkylation of synthesis structurally diversified 4-alkylpyridines. The readily available easily manipulated acids were used as alkyl radical precursors. reactions take place under mild conditions with a broad substrate scope are easy scale up gram level, they therefore potential practical value for structural modification biologically active alkylpyridine derivatives.

Language: Английский

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Photocatalytic Pyridyl-carbamoylation of Alkenes for Accessing β-Pyridyl Amides

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

Published: March 7, 2025

The β-pyridyl amide is a critical scaffold in medical discovery yet lacks efficient synthetic methods. Here, we describe, for the first time, visible-light-induced, redox-neutral radical cross-coupling reaction involving alkenes, oxamic acids, and cyanopyridines that offers versatile assembly of β-pyridylamides. This approach features mild conditions, high step efficiency, substrate breadth, providing green strategy alkene pyridyl-carbamoylation. Achieving this transformation relies on catalytic system, which adeptly avoids competing nucleophilic carbamoyl with electrophilic pyridyl radical, enabling three-component tandem process chemoselectivity.

Language: Английский

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Acyl-1,4-Dihydropyridines: Universal Acylation Reagents for Organic Synthesis

Molecules, Journal Year: 2024, Volume and Issue: 29(16), P. 3844 - 3844

Published: Aug. 13, 2024

Acyl-1,4-dihydropyridines have recently emerged as universal acylation reagents. These easy-to-make and bench-stable NADH biomimetics play the dual role of single-electron reductants sources acyl radicals. This review article discusses applications acyl-1,4-dihydropyridines in organic synthesis since their introduction 2019. Acyl-1,4-dihydropyridines, activated by photochemical, thermal or electrochemical methods, been successfully applied radical multiple diverse transformations such addition to olefins, alkynes, imines other acceptors, well late-stage functionalisation natural products APIs. Release radicals an electron can be performed under mild conditions—in green solvents, air sunlight, without use photocatalysts, photosensitizers external oxidants—which makes them ideal reagents for chemists.

Language: Английский

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Sunlight-induced Three-Component Synthesis of α-Aminoketones: A Green and Sustainable Pathway Through EDA Complex

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

We reported a sunlight-promoted, three-component reaction involving glyoxal hydrates, anilines, and 4-alkyl DHPs for the synthesis of α-aminoketones with high yields under ambient conditions without additional photocatalysts or additives.

Language: Английский

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Photocatalytic Consecutive Photoinduced Electron Transfer-Enabled C(sp³)–H Pyridylation of Dihydroquinoxalin-2-ones

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 22, 2024

A photocatalytic decyanative C(sp3)–H pyridination of dihydroquinoxalin-2-ones with 4-cyanopyridines was developed by utilizing 4CzIPN as the photocatalyst. Mechanism studies show that this organophotocatalytic direct undergoes a radical–radical cross-coupling pathway promoted consecutive photoinduced electron transfer.

Language: Английский

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Dicarbofunctionalization of Vinylarenes with Pyridine and Aldehydes via Photocatalytic Hydrogen Atom Transfer

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(21), P. 15877 - 15883

Published: Oct. 14, 2024

We describe a metal-free and mild three-component reaction utilizing vinylarenes, alkyl aldehydes, 4-cyanopyridine. In this reaction, the scope of vinylarenes aldehydes includes over 40 examples, generating variety β-pyridinyl ketones. Moreover, potential applications method have been demonstrated by functionalization pharmaceutical molecules. An acyl radical is proposed to be produced via polarity-matched hydrogen atom transfer between triplet-state diradical from benzophenone.

Language: Английский

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