Radical-Polar Crossover Enabled Triple Cleavage of CF₂Br₂: A Multicomponent Tandem Cyclization to 3-Fluoropyrazoles

Organic Letters, Journal Year: 2023, Volume and Issue: 25(32), P. 6062 - 6066

Published: Aug. 8, 2023

The elaboration of step-economy and catalytic approaches for accessing diverse fluorinated heterocyclics is highly desirable. Described herein a radical-polar crossover enabled three-component cyclization to polysubstituted fluoropyrazoles by using CF2Br2 as novel C1F1 synthon. Mechanistic experiments revealed that the in situ generation reactive intermediate gem-difluorovinylimine ion key this transformation. This protocol unlocks reactivity adds significant synthetic values fluorine chemistry.

Language: Английский

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Photoredox-Catalyzed Defluorinative Carboxylation of gem-Difluorostyrenes with Formate Salt

Organic Letters, Journal Year: 2024, Volume and Issue: 26(4), P. 883 - 888

Published: Jan. 22, 2024

Herein, we present a transition-metal-free, easy handling protocol for regioselective carboxylation of gem-difluorostyrenes with sodium formate as the C1 source. 30 examples α-fluoracrylates were obtained in yields to 80% under these conditions. A defluorinative monofluorovinyl intermediate and consecutive photoinduced electron transfer mechanism proposed after investigation.

Language: 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, Journal Year: 2023, Volume and Issue: 14(22), P. 6045 - 6051

Published: Jan. 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.

Language: Английский

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Advances in photoinduced radical–polar crossover cyclization (RPCC) of bifunctional alkenes

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 11(3), P. 895 - 915

Published: Dec. 20, 2023

Photoinduced radical–polar crossover cyclization (RPCC) of bifunctional alkenes is high synthetic utility to produce cyclic products with precise alkene design. This review summarizes the recent representative advances in field RPC.

Language: Английский

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Photoinduced radical-polar crossover cyclization reactions

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(5), P. 100945 - 100945

Published: March 5, 2024

Language: 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, Journal Year: 2024, Volume and Issue: 24(3)

Published: Jan. 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.

Language: Английский

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“On-water” defluorinative cyclization of trifluoromethyl enones with phosphine oxides: synthesis of polysubstituted furans

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(14), P. 3974 - 3981

Published: Jan. 1, 2024

A defluorinative cyclization of readily available trifluoromethyl enones with phosphine oxides for the synthesis polysubstituted furans is developed in a pure water solution.

Language: Английский

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Reversible Radical Addition Guides Selective Photocatalytic Intermolecular Thiol‐Yne‐Ene Molecular Assembly

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Jan. 19, 2024

Abstract In modern organic chemistry, harnessing the power of multicomponent radical reactions presents both significant challenges and extraordinary potential. This article delves into this scientific frontier by addressing critical issue controlling selectivity in such complex processes. We introduce a novel approach that revolves around reversible addition thiyl radicals to multiple bonds, reshaping landscape reactions. The key lies intricate interplay between reversibility energy landscapes governing C−C bond formation thiol‐yne‐ene developed not only allows prioritize cascade, dominating over alternative reactions, but also extends scope coupling products obtained from alkenes alkynes various structures electron density distributions, regardless their relative polarity difference, opening doors more versatile synthetic possibilities. present study, we provide powerful tool for atom‐economical C−S formation, paving way efficient synthesis molecules. Carrying out our experimental computational studies, elucidated fundamental mechanisms underlying cascades, knowledge can be broadly applied field chemistry.

Language: Английский

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Electron Donor–Acceptor Complex Enabled Cyclization/Sulfonylation Cascade of N-Heterocycles with Thianthrenium Salts

Organic Letters, Journal Year: 2024, Volume and Issue: 26(31), P. 6652 - 6657

Published: July 26, 2024

We report a visible-light-promoted cyclization/sulfonylation cascade of N-heterocycles with thianthrenium salts using DABSO as the SO2 surrogate. This method features excellent functional group tolerance, wide substrate scope, and late-stage elaboration bioactive relevant molecules. Mechanistic investigations reveal that photoactive electron donor–acceptor (EDA) complexes between DABCO are capable generation aryl radicals, which induce following insertion by attacking DABSO, thus triggering key radical cyclization step.

Language: Английский

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Rh(III)-Catalyzed Defluorinative [4 + 2] Annulation of N-Sulfonylarylamides with Ethyl 2-Diazo-3,3,3-trifluoropropanoate: Synthesis of 1,3,4-Functionalized Isoquinolines

Organic Letters, Journal Year: 2022, Volume and Issue: 24(49), P. 8969 - 8974

Published: Dec. 1, 2022

Using 2-diazo-3,3,3-trifluoropropanoate as a nontraditional two-carbon reaction partner, Rh(III)-catalyzed defluorinative [4 + 2] annulation for the synthesis of 1,3,4-functionalized isoquinolines was developed. The proceeds by sequential C-H carbenoid insertion, dual C-F bond cleavage/annulation, and N- to O-sulfonyl migration. resultant products were converted diverse 1,3,4-trisubstituted based on functionalization newly installed 1-sulfonate, 2-fluoro functional handles, and/or remaining ester motif.

Language: Английский

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