General and Modular Route to (Halo)alkyl BCP-Heteroaryls Enabled by α-Aminoalkyl Radical-Mediated Halogen-Atom Transfer

ACS Catalysis, Journal Year: 2023, Volume and Issue: 14(2), P. 619 - 627

Published: Dec. 28, 2023

Synthesis of bicyclo[1.1.1]pentane (BCP) heteroaryls continues to be a part the most important tasks in organic synthesis because they are significant class bioisosteres with universal applications drug discovery. However, substrate scope current multicomponent reactions is limited tertiary alkyl radicals and prefunctionalized (het)arenes due their intrinsic mechanisms, resulting decrease application value. Herein, we report straightforward alternative for (halo)alkyl BCP-heteroaryls from [1.1.1]propellane enabled by α-aminoalkyl radical-mediated halogen-atom transfer (XAT). Carbon derived commonly available precursors such as primary, secondary, halides polyhalides perform additions onto give BCP radicals, which then engage C–H/C–C couplings different heteroarenes. A wide range easily constructed moderate-to-good yields. Late-stage functionalization performed on approved derivatives proceeds good efficiency produce corresponding BCP-heteroaryls. The control experiments density functional theory (DFT) calculations reveal radical nature reaction. This approach not only verifies (XAT) strategy but also provides practical efficient route multifunctionalized BCPs, significantly expands BCP-heteroaryl-type development.

Language: Английский

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Three‐Component Reactions of Quinoxalin‐2(1H)‐ones: Recent Advances

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 11, 2023

Abstract The multicomponent reactions of quinoxalin‐2(1 H )‐ones has attracted considerable interest due to their significant biological and chemical activities. very recent advances (from 2021 the beginning 2023) on radical three‐component cascade reaction )‐one derivatives at C3 position were summarized in this mini‐review. According kind types involved, some representative examples detailed mechanism have been categorized discussed. red front was covered by Figure 1.

Language: Английский

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Enantioselective Chemodivergent Three-Component Radical Tandem Reactions through Asymmetric Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 20141 - 20148

Published: Aug. 28, 2023

Chemodivergent synthesis has been achieved in asymmetric photocatalysis. Under a dual catalyst system consisting of chiral phosphoric acid and DPZ as photosensitizer, different inorganic bases enabled the formation two sets valuable products from three-component radical tandem transformations 2-bromo-1-arylenthan-1-ones, styrenes, quinoxalin-2(1H)-ones. The key to success was distinct pKa environment, which radicals that formed on quinoxalin-2(1H)-one rings after addition processes underwent either single-electron oxidation or reduction. In addition, this work represents first use quinoxalin-2(1H)-ones photoredox catalysis.

Language: Английский

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An Overview of α‐Aminoalkyl Radical Mediated Halogen‐Atom Transfer

ChemCatChem, Journal Year: 2023, Volume and Issue: 15(21)

Published: Aug. 14, 2023

Abstract The merging of photocatalysis with halogen‐atom transfer (XAT) processes has proven to be a versatile tool for the generation carbon‐centered radicals in organic synthesis. XAT are unique that they generate without requiring use strong reductants necessary traditional single electron (SET) activation halides. Pathways achieve synthetic applications can categorized into three major sections: i) heteroatom‐based activators, ii) metal‐based and iii) carbon‐based activators among which α‐aminoalkyl have taken center stage. Access these as reagents gained significant attention past few years due robustness reactions, simplicity required, broadness their applications. Generation is simply achieved through oxidation tertiary amines, after deprotonation at α‐position generates radicals. Due wide scope amines available tunable nucleophilicity radical formed, this strategy become an attractive alternative heteroatom/metal‐based XAT. In minireview, we focus our on recent (2020–2023) developments uses robust technology mediate processes.

Language: Английский

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Visible light-mediated ring opening and cyclization of aryl cyclopropanes: efficient synthesis of pyrrolo[1,2-a]quinoxalin-4(5H)-ones with antineoplastic activity

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(6), P. 1758 - 1764

Published: Jan. 1, 2024

This study describes an efficient and green approach for the synthesis of potentially bioactive pyrrolo[1,2- a ]quinoxalin-4(5 H )-ones with appreciable functional group tolerance wide substrate scope.

Language: Английский

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Photoalkylation/-arylation of ortho-Diketones with Unactivated Organic Halides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(21), P. 3847 - 3852

Published: May 22, 2023

A new method for conducting a reductive alkylation/arylation of 1,2-diketones using visible light and unactivated organic halides is presented in this article. This technique does not require photocatalyst employs Et3N, tertiary amine, as promoter. amine aids generating ketyl radical an α-aminoalkyl radical, which engages C-X bond activation via halogen atom transfer process (XAT). approach's success hinges on utilizing Et3N the article's mild straightforward protocol allows significantly expanding halide substrates, including primary, secondary, aromatic various functional groups.

Language: Английский

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Visible-Light-Induced Three-Component 1,2-Alkylpyridylation of Alkenes via a Halogen-Atom Transfer Process

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(3), P. 1703 - 1708

Published: Jan. 16, 2024

Visible-light-induced three-component 1,2-alkylpyridylation of alkenes with unactivated alkyl iodides and aryl cyanides is reported via a photocatalytic halogen-atom transfer (XAT) strategy. This metal-free protocol utilizes readily available tertiary alkylamine as the terminal reductant to smoothly convert into corresponding carbon radical species. The reaction features broad substrate scope, excellent functional group tolerance, high efficiency, mild conditions. practicability this methodology further demonstrated in late-stage difunctionalization bioactive molecules.

Language: Английский

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Photocatalytic, Intermolecular Olefin Alkylcarbofunctionalization Triggered by Haloalkyl Radicals Generated via Halogen Atom Transfer

Organic Letters, Journal Year: 2023, Volume and Issue: 25(30), P. 5558 - 5562

Published: July 20, 2023

A visible-light-mediated, haloalkyl-radical-initiated, three-component olefin difunctionalization is reported. The application of haloalkyl radicals generated via halogen atom abstraction by α-aminoalkyl has been demonstrated for accessing a new halogenated chemical space. Overall, the alkylcarbofunctionalization styrenes was accomplished employing them as (poly)haloalkyl radical acceptors and subsequent C-C bond formation with quinoxalinones.

Language: Английский

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Metal-free radical bicyclization/chloroalkylarylation of 1,6-enynes with chloroalkanes

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(29), P. 3938 - 3941

Published: Jan. 1, 2024

A metal-free radical bicyclization of chloralkanes and 1,6-enynes produces various polychlorinated/chlorinated polyheterocycles.

Language: Английский

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Visible-Light-Induced C(sp³)-H Activation for Minisci Alkylation of Pyrimidines Using CHCl₃ as Radical Source and Oxidant

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

Published: Jan. 14, 2025

A highly efficient Minisci reaction of pyrimidines with alkyl radical generated from visible-light-induced activation simple C(sp3)-H feedstocks such as (cyclo)alkanes, ethers, alcohols, esters, and amides is reported. mechanistic study revealed that was via hydrogen atom transfer (HAT) dichloromethyl (·CHCl2), which by photoreduction chloroform.

Language: Английский

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