Progress in Photoinduced Radical Reactions using Electron Donor‐Acceptor Complexes

Asian Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 10(4), P. 711 - 748

Published: Feb. 11, 2021

Abstract Photocatalyzed organic synthesis transformation is a remarkable green synthetic strategy because of the advantages operational simplicity, high chemoselectivities, cheap, and environmental benignancy, along with extensive applications in fields organic, pharmaceutical functional material chemistry. Generally, photoredox catalysts or photosensitizers are necessary for generation their excited states to perform successive oxidative reductive reactions through single electron transfer (SET) energy (ET) process. Furthermore, exploration colored donor‐acceptor (EDA) complex charge (CT) between an electron‐rich electron‐poor substrate provides chance deliver intermediate under irradiation light, resulting formation radical activate species induce various reactions. These were performed without need any external photocatalysts mild reaction conditions. Herein, this review focuses on recent progress photoinduced addition reactions, borylations, radical‐radical cross‐coupling degradation cascade cyclization via EDA complexes. We highlight these novel methodologies applications, as well mechanisms. This will help provide references medicinal chemists who charmed by photochemical transformations based

Language: Английский

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Recent Advances in Employing Catalytic Donors and Acceptors in Electron Donor–Acceptor Complex Photochemistry

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(16), P. 10555 - 10563

Published: July 29, 2022

Electron donor–acceptor (EDA) complexes provide a means to initiate radical reactions under visible light irradiation using substrates that do not absorb individually. Catalytic approaches complex formation are vital for advancing this synthetic strategy as it decouples the complexation and photogeneration of radicals from substrate functionalization, limitation inherent stoichiometric restricts structural diversity. This Synopsis highlights recent developments in EDA photochemistry which either donor or acceptor employed catalytically.

Language: Английский

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Shining light on halogen-bonding complexes: a catalyst-free activation mode of carbon–halogen bonds for the generation of carbon-centered radicals

Chemical Science, Journal Year: 2023, Volume and Issue: 14(21), P. 5545 - 5568

Published: Jan. 1, 2023

This review provides a comprehensive overview on examples of how photochemical excitation halogen-bonding complexes can be useful for the generation carbon-centered radicals and their participation in synthetic organic transformations.

Language: Английский

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Review and Theoretical Analysis of Fluorinated Radicals in Direct C_Ar−H Functionalization of (Hetero)arenes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(16)

Published: Jan. 29, 2024

Abstract We highlight key contributions in the field of direct radical C Ar − H (hetero)aromatic functionalization involving fluorinated radicals. A compilation Functional Group Transfer Reagents and their diverse activation mechanisms leading to release radicals are discussed. The substrate scope for each is analyzed classified into three categories according electronic properties substrates. Density functional theory computational analysis provides insights chemical reactivity several through electrophilicity nucleophilicity parameters. Theoretical reduction potentials also highlights remarkable correlation between oxidizing ability. It established that highly (e.g. ⋅OCF 3 ) capable engaging single‐electron transfer (SET) processes rather than addition, which good agreement with experimental literature data. scale, based on barrier addition these benzene elaborated using high accuracy DLPNO‐(U)CCSD(T) method.

Language: Английский

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Promising reagents for difluoroalkylation

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(17), P. 2538 - 2575

Published: Jan. 1, 2020

This review describes recent advances in difluoroalkylation reactions using different substrates.

Language: Английский

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Visible-Light-Induced C–F Bond Activation for the Difluoroalkylation of Indoles

Organic Letters, Journal Year: 2022, Volume and Issue: 24(46), P. 8542 - 8546

Published: Nov. 14, 2022

An aryl disulfide mediated C-F bond activation of the trifluoromethyl group to generate valuable gem-difluoroalkylindoles is described. This method relies on readily available commodity reagents under mild reaction conditions and represents first transition-metal-free redox-neutral strategy. The employs various substituted indoles α-fluoro-substituted esters. Further, this mode was also amenable trifluoromethylated arenes for preparation bis-benzylic gem-difluoromethylenes between indole arene substructures, providing access a unique chemical space.

Language: Английский

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Recent advances in the synthesis of fluorinated amino acids and peptides

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(11), P. 1434 - 1448

Published: Jan. 1, 2023

The site-selective modification of amino acids, peptides, and proteins has always been an intensive topic in organic synthesis, medicinal chemistry, chemical biology due to the vital role acids life. Among developed methods, introduction fluorine functionalities into peptides emerged as a useful approach change their physicochemical biological properties. With increasing demand for life science, direct fluorination/fluoroalkylation also received attention because unique properties atom(s) that can protein structure, increase lipophilicity, enable functionality tracer or probe studies. In this feature article, we summarized recent advances synthesis fluorinated wherein two strategies have discussed. One is based on building blocks prepare with diversified structures, including transformations imines nickel-catalyzed dicarbofunctionalization alkenes bromodifluoroacetate its derivatives; other fluorination/fluoroakylation proteins, which selective functional groups serine, threonine, tyrosine, tryptophan, cysteine lead wide range α-amino featuring synthetic convenience late-stage biomacromolecules. These complement each other, transition-metal catalysis new fluoroalkylating reagents provide powerful tools selectively access showing prospect chemistry biology.

Language: Английский

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Triarylamines as catalytic donors in light-mediated electron donor–acceptor complexes

Chemical Science, Journal Year: 2023, Volume and Issue: 14(13), P. 3470 - 3481

Published: Jan. 1, 2023

Recently, photochemistry of Electron Donor-Acceptor (EDA) complexes employing catalytic amounts electron donors have become interest as a new methodology in the catalysis field, allowing for decoupling transfer (ET) from bond-forming event. However, examples practical EDA systems regime remain scarce, and their mechanism is not yet well-understood. Herein, we report discovery an complex between triarylamines α-perfluorosulfonylpropiophenone reagents, catalyzing C-H perfluoroalkylation arenes heteroarenes under visible light irradiation pH- redox-neutral conditions. We elucidate this reaction using detailed photophysical characterization complex, resulting triarylamine radical cation, its turnover

Language: Английский

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Expanding Reaction Profile of Allyl Carboxylates via 1,2-Radical Migration (RaM): Visible-Light-Induced Phosphine-Catalyzed 1,3-Carbobromination of Allyl Carboxylates

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(15), P. 8275 - 8284

Published: April 5, 2023

Allyl carboxylates are useful synthetic intermediates in a variety of organic transformations, including catalytic nucleophilic/electrophilic allylic substitution reactions and 1,2-difunctionalization reactions. However, the 1,3-difunctionalization allyl remains elusive. Herein, we report first photoinduced, phosphine-catalyzed 1,3-carbobromination carboxylates, affording range valuable substituted isopropyl (sIPC). The transformation has broad functional group tolerance, is amenable to late-stage modification complex molecules gram-scale synthesis, expands reaction profiles phosphine catalysis. Preliminary experimental computational studies suggest non-chain-radical mechanism involving formation an electron donor-acceptor complex, 1,2-radical migration (RaM), Br-atom transfer processes. We anticipate that 1,2-RaM reactivity radical will both serve as platform for development new transformations synthesis.

Language: Английский

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Photochemical Synthesis of Lactones, Cyclopropanes and ATRA Products: Revealing the Role of Sodium Ascorbate**

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 7, 2024

Abstract Light‐mediated processes have received significant attention, since they re‐surfaced unconventional reactivity platforms, complementary to conventional polar chemistry. γ‐Lactones and cyclopropanes are prevalent moieties, found in numerous natural products pharmaceuticals. Among various methods for their synthesis, light‐mediated protocols coming the spotlight, although these contingent upon use of photoorgano‐ or metal‐based catalysts. Herein, we introduce a novel photochemical activation iodo‐reagents via cheap sodium ascorbate ascorbic acid enable homolytic scission addition onto double bonds. The developed protocol was applied successfully formal [3+2] cycloaddition synthesis γ‐lactones, traditional atom transfer radical (ATRA) reactions one‐pot two‐step conversion alkenes cyclopropanes. In all cases, desired were obtained good high yields, while reaction mechanism thoroughly investigated. Depending on nature iodo‐reagent, halogen hydrogen‐bonded complex is formed, which initiates process.

Language: Английский

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