Reactivity of oximes for diverse methodologies and synthetic applications

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(1), P. 24 - 36

Published: Jan. 12, 2022

Language: Английский

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Recent Advances in C-F Bond Cleavage Enabled by Visible Light Photoredox Catalysis

Molecules, Journal Year: 2021, Volume and Issue: 26(22), P. 7051 - 7051

Published: Nov. 22, 2021

The creation of new bonds via C-F bond cleavage readily available per- or oligofluorinated compounds has received growing interest. Using such a strategy, myriad valuable partially fluorinated products can be prepared, which otherwise are difficult to make by the conventional formation methods. Visible light photoredox catalysis been proven as an important and powerful tool for defluorinative reactions due its mild, easy handle, environmentally benign characteristics. Compared classical activation that proceeds two-electron processes, radicals key intermediates using visible catalysis, providing modes bonds. In this review, summary light-promoted since 2018 was presented. contents were classified fluorosubstrates, including polyfluorinated arenes, gem-difluoroalkenes, trifluoromethyl alkenes. An emphasis is placed on discussion mechanisms limitations these reactions. Finally, my personal perspective future development rapidly emerging field provided.

Language: Английский

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Precise electro-reduction of alkyl halides for radical defluorinative alkylation

Science China Chemistry, Journal Year: 2022, Volume and Issue: 65(4), P. 762 - 770

Published: March 10, 2022

Language: Английский

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Synthesis of 5-Fluoro-dihydroindolizines from Pyrrole-2-acetic Acids and Trifluoromethyl Alkenes via Dual C–F Bond Cleavage in a CF₃ Group

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(7), P. 4801 - 4812

Published: March 17, 2022

Herein, we describe the synthesis of 5-fluoro-dihydroindolizines via dual C–F bond cleavage in a trifluoromethyl group. The photocatalytic defluorinative coupling pyrrole-2-acetic acids and α-trifluoromethyl alkenes cleaved first bond, providing gem-difluoroalkenes bearing an unprotected pyrrole motif. Subsequently, intramolecular SNV reaction closed ring by forming C–N concomitantly with second bond. Using indole-2-acetic as substrates, reactions also allow assembly 6-fluoro-dihydropyrido[1,2-a]indoles.

Language: Английский

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Photocatalytic Phosphine-Mediated Thioesterification of Carboxylic Acids with Disulfides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(44), P. 8033 - 8037

Published: Oct. 27, 2023

Herein, a practical and effective synthesis of thioesters from readily available carboxylic acids odorless disulfides was developed under photocatalytic conditions. This approach involves phosphoranyl radical-mediated fragmentation to generate acyl radicals allows for incorporation both S atoms the into desired products. In addition batch reactions, continuous-flow reactor employed, enabling rapid thioester on gram scale. Preliminary experimental mechanistic studies dalcetrapib are also demonstrated.

Language: Английский

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Synergistic Brønsted Base/Photoredox‐Catalyzed Three‐Component Coupling with Malonates to Synthesize δ‐Hydroxy Esters and δ‐Keto Esters

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: 42(9), P. 957 - 962

Published: Jan. 18, 2024

Comprehensive Summary Multicomponent alkene 1,2‐dicarbofunctionalizations (DCFs) have emerged as a powerful strategy to rapidly incorporate both two carbon subunits across one C—C double bond in step for enhancing molecular complexity and diversity. To the best of our knowledge, there is only report on photoredox‐catalyzed three‐component DCFs with malonates through radical−radical cross‐coupling, while radical‐polar crossover (RPC)‐type were still rare. Herein, we describe redox‐neutral RPC‐type 1,2‐dialkylation styrenes aldehydes synergistic Brønsted base/photoredox catalysis system. This transition‐metal‐free provides an efficient clean approach broad variety δ‐hydroxy esters also features exceptionally mild conditions, wide compatibility substrate scope functional groups, high atomic economy. Moreover, 1,2‐alkylacylation from same starting materials was achieved one‐pot manner such coupling subsequent two‐electron oxidation process, providing set δ‐keto interest pharmaceutical research.

Language: Английский

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Electroreductive Cross‐Coupling of Trifluoromethyl Alkenes and Redox Active Esters for the Synthesis of Gem‐Difluoroalkenes

Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 28(2)

Published: Nov. 11, 2021

An electroreductive access to gem-difluoroalkenes has been developed through the decarboxylative/defluorinative coupling of N-hydroxyphtalimides esters and α-trifluoromethyl alkenes. The electrolysis is performed under very simple reaction conditions in an undivided cell using cheap carbon graphite electrodes. This metal-free transformation features broad scope with good excellent yields. Tertiary, secondary as well primary alkyl radicals could be easily introduced. α-aminoacids L-aspartic L-glutamic acid-derived redox active were reactive partners furnishing potentially relevant gem-difluoroalkenes. In addition, it demonstrated that our electrosynthetic approach toward synthesis use prepared Kratitsky salt radical precursor via a deaminative/defluorinative carbofunctionalization trifluoromethylstyrene.

Language: Английский

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Access to gem-Difluoroalkenes via Organic Photoredox-Catalyzed gem-Difluoroallylation of Alkyl Iodides

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 87(2), P. 1574 - 1584

Published: Dec. 29, 2021

An organic photoredox-catalyzed gem-difluoroallylation of α-trifluoromethyl alkenes with alkyl iodides via C-F bond cleavage for the synthesis gem-difluoroalkene derivatives is reported. This transition-metal-free transformation utilized a readily available dye 4CzIPN as sole photocatalyst and employed common chemical N,N,N',N'-tetramethylethylenediamine radical activator halogen-atom transfer. In addition, variety iodides, including primary, secondary, tertiary were tolerated provided good to high yields.

Language: Английский

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Nickel‐Catalyzed Unsymmetrical Bis‐Allylation of Alkynes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(17)

Published: Feb. 24, 2023

The catalytic bis-allylation of alkynes is an important but challenging protocol to construct all-carbon tetra-substituted alkenes. Particularly, the unsymmetrical remains as underexplored task date. We herein report unprecedented by simultaneously utilizing electrophilic trifluoromethyl alkene and nucleophilic allylboronate allylic reagents. With aid robust Ni0 /NHC catalysis, valuable skipped trienes can be obtained in high regio- stereo-selectivities under mild conditions. Mechanistic studies indicate that reaction may proceed through a β-fluorine elimination nickelacycle followed transmetalation step with allylboronate. present method exhibits good tolerance various functional groups. Besides, triene products undergo array elaborate transformations, which highlights potential applications this strategy.

Language: Английский

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Photoredox Catalytic Phosphine-Mediated Deoxygenation of Hydroxylamines Enables the Construction of N-Acyliminophosphoranes

Organic Letters, Journal Year: 2022, Volume and Issue: 24(34), P. 6247 - 6251

Published: Aug. 23, 2022

The chemistry of phosphoranyl radicals has received increasing attention in recent years. Here, we report the generation amidyl through photocatalytic deoxygenation hydroxylamines with triphenylphosphine. This methodology offers a novel and convenient route to diverse range N-acyliminophosphoranes moderate good yields under visible-light photoredox conditions. Fluorescence quenching experiments suggest that excited-state organic photocatalyst (4CzIPN) was oxidatively quenched by Cu(II) salt.

Language: Английский

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