Generation and Application of Aryl Radicals Under Photoinduced Conditions

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(31)

Published: March 28, 2024

Abstract Photoinduced aryl radical generation is a powerful strategy in organic synthesis that facilitates the formation of diverse carbon‐carbon and carbon‐heteroatom bonds. The synthetic applications photoinduced complex compounds, including natural products, physiologically significant molecules, functional materials, have received immense attention. An overview current developments production methods their uses given this article. A generalized idea how to choose reagents approach for radicals described, along with techniques associated mechanistic insights. Overall, article offers critical assessment results as well selection reaction parameters specific context cascades, cross‐coupling reactions, functionalization, selective C−H functionalization substrates.

Language: Английский

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Unveiling N-Fused Nitreniums as Potent Catalytic Photooxidants

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 3603 - 3608

Published: Jan. 31, 2024

The first example of a hitherto-unknown facet catalytic photooxidant capability nitrenium cations is reported herein. fundamental limitation inability the traditional and nitreniums to achieve excited-state redox potential beyond +2.0 V (vs Ag/AgCl), primary requirement for powerful photooxidant, addressed in this work by developing structurally unique class N-fused cations, with required structural engineering involving extensive π-conjugation through ring fusion at site, which enabled significant lowering LUMO energy easy reduction excited state (excited-state up +2.5 vs facilitated effective delocalization/stabilization generated radical. This finding opens new way discover novel useful (photo)catalytic properties just Lewis acidity.

Language: Английский

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CO₂^•– Enabled Synthesis of Phenanthridinones, Oxindoles, Isoindolinones, and Spirolactams

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

Published: Feb. 28, 2025

We report herein that photoinduced CO2•– enabled reductive intramolecular radical cyclization of a variety aryl iodide derivatives to the corresponding phenanthridinone, oxindole, isoindolinone, and spirolactam in good yields. Preliminary mechanistic studies suggested generation through homolysis cesium formate presence light, further involvement was directly proved by trapping with diphenyl styrene TEMPO.

Language: Английский

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Visible-Light Photocatalytic Reduction of Aryl Halides as a Source of Aryl Radicals

Molecules, Journal Year: 2022, Volume and Issue: 27(17), P. 5364 - 5364

Published: Aug. 23, 2022

Aryl- and heteroaryl units are present in a wide variety of natural products, pharmaceuticals, functional materials. The method for reduction aryl halides with ubiquitous distribution is highly sought after late-stage construction various aromatic compounds. visible-light-driven to radicals by electron transfer provides an efficient, simple, environmentally friendly the This review summarizes recent progress generation metal complexes, organic compounds, semiconductors as catalysts, alkali-assisted reaction system. ability mechanism visible light induced systems summarized, intending illustrate comprehensive introduction this research topic readers.

Language: Английский

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Photoinduced N-Heterocyclic Nitrenium-Catalyzed Single Electron Reduction of Acyl Fluorides for Phenanthridine Synthesis

Organic Letters, Journal Year: 2023, Volume and Issue: 25(3), P. 565 - 568

Published: Jan. 13, 2023

Acyl fluorides are versatile reagents in organic synthesis. However, there is no precedent to employ acyl as radical precursors. We herein report an N-heterocyclic nitrenium iodide salt-catalyzed photoreduction of produce radicals, which could react with 2-isocyanobiaryls afford various carbonyl phenanthridines.

Language: Английский

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Triarylamine-Substituted Benzimidazoliums as Electron Donor–Acceptor Dyad-Type Photocatalysts for Reductive Organic Transformations

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 10236 - 10248

Published: May 2, 2023

Triarylamine-substituted benzimidazoliums (BI+-PhNAr2), new electron donor-acceptor dyad molecules, were synthesized. Their photocatalytic properties for reductive organic transformations explored using absorption and fluorescence spectroscopy, redox potential determinations, density functional theory calculations, transient reduction reactions of selected substrates. The results show that irradiation BI+-PhNAr2 promotes photoinduced intramolecular transfer to form a long-lived (∼300 μs) charge shifted state (BI•-PhN•+Ar2). In the pathway photocatalysis substrates, BI•-PhN•+Ar2 is subsequently transformed neutral benzimidazolyl radical (BI•-PhNAr2) by single-electron from donor 1,3-dimethyl-2-phenylbenzimidazoline (BIH-Ph) serving as cooperative agent. Among explored, bromo-substituted analogue BI+-PhN(C6H4Br-p)2 in conjunction with BIH-Ph demonstrates most consistent catalytic performance.

Language: Английский

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Additive free, N-heterocyclic nitrenium catalyzed photoreduction of cycloketone oxime esters

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(5), P. 1160 - 1165

Published: Jan. 1, 2023

N-Heterocyclic nitrenium iodide salts can be used as ideal charge transfer complex catalysts for the photoreduction of cycloketone oxime esters.

Language: Английский

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N-Heterocyclic Nitrenium-Catalyzed Photohomolysis of CF₃SO₂Cl for Alkene Trifluoromethylation

Organic Letters, Journal Year: 2023, Volume and Issue: 25(33), P. 6189 - 6194

Published: Aug. 14, 2023

N-Heterocyclic nitreniums (NHNs) have been utilized as Lewis acid catalysts to activate substrates with lone pairs. Alternative their conventional applications, we discovered that NHNs can also serve charge transfer complex catalysts. Herein, present another potential of by utilizing a weak interaction between and CF3SO2Cl. The method promotes CF3SO2Cl undergo photohomolysis, resulting in the CF3 radical. Mechanistic studies suggested could be due π-hole effect NHNs.

Language: Английский

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Radical Replacement Process for Ligated Boryl Radical-Mediated Activation of Unactivated Alkyl Chlorides for C(sp³)–C(sp³) Bond Formation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 12, 2024

The ligated boryl radical (LBR) has emerged as a potent tool for activating alkyl halides in transformations through halogen-atom transfer (XAT). However, unactivated chlorides still present an open challenge this strategy. We herein describe new activation mode of the LBR to construct C(sp

Language: Английский

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Visible-Light-Mediated Radical α-C(sp³)─H gem-Difluoroallylation of Amides with Trifluoromethyl Alkenes via Halogen Atom Transfer and 1,5-Hydrogen Atom Transfer

Organic Letters, Journal Year: 2025, Volume and Issue: 27(10), P. 2377 - 2382

Published: March 5, 2025

Direct gem-difluoroallylation at the α-carbonyl position is a challenging process by conventional methods. Herein we report photocatalytic radical α-C(sp3)─H of amides with trifluoromethyl alkenes to access target compounds good yields and functional group tolerance. The mild effective conditions allow gem-difluoroalkene motifs as carbonyl bioisosteres incorporated concisely some complex molecules, including gemfibrozil estrone derivatives, presenting great potential for late-stage functionalization drugs, natural products, bioactive intermediates. Mechanistic investigations suggest pathway combining XAT 1,5-HAT.

Language: Английский

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