Recent Advances in Visible-Light-Mediated Amide Synthesis

Molecules, Год журнала: 2022, Номер 27(2), С. 517 - 517

Опубликована: Янв. 14, 2022

Visible-light photoredox catalysis has attracted tremendous interest within the synthetic community. As such, activation mode potentially provides a more sustainable and efficient platform for of organic molecules, enabling invention many controlled radical-involved reactions under mild conditions. In this context, amide synthesis via strategy received growing due to ubiquitous presence structural motif in numerous natural products, pharmaceuticals functionalized materials. Employing strategy, wide variety amides can be prepared effectively from halides, arenes even alkanes irradiation visible light. These methods provide robust alternative well-established strategies that involve condensation between carboxylic acid amine mediated by stoichiometric activating agent. review, representative progresses made on through light-mediated radical are summarized.

Язык: Английский

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Photoredox radical/polar crossover enables C–H gem-difunctionalization of 1,3-benzodioxoles for the synthesis of monofluorocyclohexenes

Chemical Science, Год журнала: 2023, Номер 14(22), С. 6045 - 6051

Опубликована: Янв. 1, 2023

A photocatalytic C-H gem-difunctionalization of 1,3-benzodioxoles with two different alkenes for the synthesis highly functionalized monofluorocyclohexenes is described. Using 4CzIPN as photocatalyst, direct single electron oxidation allows their defluorinative coupling α-trifluoromethyl to produce gem-difluoroalkenes in a redox-neutral radical polar crossover manifold. The bond resultant γ,γ-difluoroallylated was further via addition electron-deficient using more oxidizing iridium photocatalyst. capture situ generated carbanions by an electrophilic gem-difluoromethylene carbon and consecutive β-fluoride elimination afford monofluorocyclohexenes. synergistic combination multiple termination pathways enables rapid incorporation molecular complexity stitching simple readily accessible starting materials together.

Язык: Английский

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Direct Hydrodefluorination of CF₃-Alkenes via a Mild S_N2′ Process Using Rongalite as a Masked Proton Reagent

Organic Letters, Год журнала: 2023, Номер 25(13), С. 2294 - 2299

Опубликована: Март 23, 2023

A concise and efficient hydrodefluorination process was developed for the synthesis of gem-difluoroalkenes. This reaction employs rongalite as a masked proton source does not require any additional catalysts or reductants. Notably, trifluoromethyl alkenes having both terminal internal double bonds are compatible with this process, allowing wider range substrates. The successful late-stage functionalizations pharmaceuticals gram-scale syntheses were used to demonstrate viability method.

Язык: Английский

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Diastereoselective Synthesis of Monofluorocyclohexenes through Photocatalyzed Cascade Cyclization of gem‐Difluoroalkenes and α,β‐Unsaturated Carbonyl Compounds

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(20)

Опубликована: Март 16, 2023

Monofluoroalkenes are nonhydrolyzable mimetics of amides. Previous work focused on the synthesis non-cyclic monofluoroalkenes. However, diastereoselective monofluorocyclohexenes from substrates is challenging. Herein, we report first photocatalyzed cascade cyclization reactions readily available α,β-unsaturated carbonyl compounds and gem-difluoroalkenes for highly functionalized monofluorocyclohexenes. The reaction shows broad substrate scope with high diastereoselectivity (>30 examples, up to 86 % yield, >20 : 1 dr). post-reaction transformations products demonstrate synthetic potential this methodology.

Язык: Английский

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Picking Two out of Three: Defluorinative Annulation of Trifluoromethyl Alkenes for the Synthesis of Monofluorinated Carbo‐ and Heterocycles

The Chemical Record, Год журнала: 2024, Номер 24(3)

Опубликована: Янв. 22, 2024

Abstract The increasing demand of organofluorine compounds in medicine, agriculture, and materials sciences makes sophisticated methods for their synthesis ever more necessary. Nowadays, not only the C−F bond formation but also selective cleavage readily available poly‐ or perfluorine‐containing have become powerful tools effective compounds. defluorinative cross‐coupling trifluoromethyl alkenes with various nucleophiles radical precursors an S N 2’ manner is a convergent route to access gem ‐difluoroalkenes, which turn react via V‐type reaction. If V reactions occur intramolecularly, dual allows facile assembly monofluorinated cyclic skeletons structural complexity diversity. In this personal account, we summarized advances field on basis coupling cyclization partners, including binucleophiles, alkynes, diradical bearing nucleophilic site. Accordingly, annulation can be achieved by base‐mediated sequential 2′/S reactions, transition metal catalyzed mediated photoredox catalysis, combination photocatalytic context seminal works others field, concise summary contributions authors offered.

Язык: Английский

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Photocatalytic Three-Component Reductive Coupling Synthesis of gem-Difluorohomoallyl Secondary Amines

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

gem-Difluorohomoallyl amines, an important class of gem-difluoroalkenes, are prevalent moieties in many bioactive compounds. However, limited methods suitable for the synthesis this type compound containing secondary amines. Here, we display a photocatalytic multicomponent protocol gem-difluoroalkenes which makes use readily available materials: arylamines, alkyl aldehydes, and α-trifluoromethyl alkenes. Moreover, ketones amines also substrates. Preliminary mechanistic experiments indicate that key α-amino radical was involved, generated from reduction situ-formed imines (or iminium ions) by reduced photocatalyst. Subsequent addition to alkenes β-F elimination deliver desired products.

Язык: Английский

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Photocatalytic Defluorinative Three-Component Reaction of α-Trifluoromethyl Alkenes, Alkenes, and Sodium Sulfinates: Synthesis of Monofluorocyclopentenes

Organic Letters, Год журнала: 2022, Номер 24(32), С. 5946 - 5950

Опубликована: Авг. 4, 2022

A photocatalytic three-component reaction of α-trifluoromethyl alkenes, electron-rich and sodium sulfinates for the synthesis gem-difluoroalkenes in a radical/polar crossover manner was developed. Due to strong electron-withdrawing nature sulfonyl group, resultant can be converted into various monofluorocyclopentenes via intramolecular base-mediated SNV reactions one pot.

Язык: Английский

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Nickel-Catalyzed Exhaustive Hydrodefluorination of Perfluoroalkyl Arenes

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(20), С. 11449 - 11456

Опубликована: Май 4, 2023

Perfluoroalkyl compounds are persistent environmental pollutants due to their strong C(sp3)-F bonds. Hydrodefluorination has emerged as a potential alternative disposal method for perfluoroalkyl compounds. Although the transformation of trifluoromethyl arenes into corresponding methyl been studied by several research groups, hydrodefluorination reactions longer chains remain rare. Herein, we report exhaustive pentafluoroethyl and longer-chain analogues using molecular nickel catalysis. Despite cleavage multiple bonds, reaction already proceeds upon gentle heating (60 °C). A mechanistic investigation indicated that via benzylic followed homobenzylic ones. We reveal roles Ni catalyst, which include C-F bond cleavage, promotion HF elimination, hydrosilylation.

Язык: Английский

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Exhaustive Hydrodefluorination or Deuterodefluorination of Trifluoromethylarenes via Metal-Free Photoredox Catalysis

Organic Letters, Год журнала: 2024, Номер 26(4), С. 928 - 932

Опубликована: Янв. 25, 2024

Perfluoroalkyl compounds are persistent environmental pollutants due to their chemical and thermal stability. Hydrodefluorination is one of the most promising strategies for disposal fluorine-containing compounds, which has attracted much attention from a broad spectrum scientific communities. Herein, we disclose metal-free, visible-light-promoted protocol exhaustive hydrodefluorination wide variety trifluoromethylarenes with up 95% yields. Moreover, methyl-d3 groups can be obtained via deuterium water D ratio 94%.

Язык: Английский

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Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond

Chemical Society Reviews, Год журнала: 2024, Номер 53(9), С. 4741 - 4785

Опубликована: Янв. 1, 2024

The review summarizes advances in the radical chemistry of polyfluorinated arenes under photocatalytic conditions. fluoroaryl fragment serves as enabling motif for reaction design and efficient generation reactive intermediates.

Язык: Английский

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