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

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

Published: Jan. 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.

Language: Английский

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Transition-Metal-Free, Site-Selective C–F Arylation of Polyfluoroarenes via Electrophotocatalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(37), P. 17261 - 17268

Published: Sept. 7, 2022

Direct CAr-F arylation is effective and sustainable for synthesis of polyfluorobiaryls with different degrees fluorination, which are important motifs in medical material chemistry. However, no aid transition metals, the engagement bond activation has proved difficult. Herein, an unprecedented transition-metal-free strategy reported site-selective polyfluoroarenes simple (het)arenes. By merging N,N-bis(2,6-diisopropylphenyl)perylene-3,4,9,10-bis(dicarboximide)-catalyzed electrophotocatalytic reduction anodic nitroxyl radical oxidation cell, various polyfluoroaromatics (2F-6F 8F), especially inactive partially fluorinated aromatics, undergo sacrificial-reagents-free C-F high regioselectivity, yields comparable to those transition-metal catalysis. This atom- step-economic protocol features a paired electrocatalysis organic mediators both cathodic processes. The broad substrate scope good functional-group compatibility highlight merits this operationally strategy. Moreover, easy gram-scale late-stage functionalization collectively advocate practical value, would promote vigorous development fluorine

Language: Английский

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Transition metal-free photochemical C–F activation for the preparation of difluorinated-oxindole derivatives

Chemical Science, Journal Year: 2023, Volume and Issue: 14(9), P. 2379 - 2385

Published: Jan. 1, 2023

The development of strategies for single and selective C-F bond activation represents an important avenue to overcome limitations in the synthesis valuable fluorine-containing compounds. synthetic medicinal research communities would benefit from new routes that access such relevant molecules a simple manner. Herein we disclose straightforward mechanistically distinct pathway generate gem-difluoromethyl radicals their installation onto N-arylmethacrylamides preparation difluorinated oxindole derivatives. To achieve operational simplicity, use readily available benzenethiol as photocatalyst under open-to-air conditions was developed, demonstrating facile multigram targeted fluorinated molecules. Additionally, dispersion-corrected density functional theory (DFT) empirical investigations provide basis support proposed reaction pathway, indicating arene thiolate is efficient organophotocatalyst this transformation.

Language: Английский

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Metallomimetic C–F Activation Catalysis by Simple Phosphines

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(3), P. 2005 - 2014

Published: Jan. 11, 2024

Delivering metallomimetic reactivity from simple p-block compounds is highly desirable in the search to replace expensive, scarce precious metals by cheap and abundant elements catalysis. This contribution demonstrates that catalysis, involving facile redox cycling between P(III) P(V) oxidation states, possible using only simple, cheap, readily available trialkylphosphines without need enforce unusual geometries at phosphorus or use external oxidizing/reducing agents. Hydrodefluorination aminodefluorination of a range fluoroarenes was realized with good very yields under mild conditions. Experimental computational mechanistic studies show phosphines undergo oxidative addition fluoroaromatic substrate via Meisenheimer-like transition state form fluorophosphorane. undergoes pseudotransmetalation step silane, initial fluoride transfer P Si, give experimentally observed phosphonium ions. Hydride hydridosilicate counterion then leads hydridophosphorane, which reductive elimination product reform phosphine catalyst. behavior analogous many classical transition-metal-catalyzed reactions so rare example both functional mechanistically catalysis main-group element system. Crucially, reagents used are commercially, easy handle, making these realistic prospect wide academic industrial settings.

Language: Английский

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Halogen Atom Transfer-Induced Homolysis of C–F Bonds by the Excited-State Boryl Radical

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 22874 - 22880

Published: Aug. 2, 2024

A novel reactivity toward C-F bond functionalization has been developed, which could be designated as fluorine atom transfer (FAT). photoexcited state of an

Language: Английский

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Defluorophosphorylation of fluoroalkyl peroxides for the synthesis of highly substituted furans

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(5), P. 2000 - 2010

Published: Jan. 1, 2023

A highly tunable defluorophosphorylation of fluorinated peroxides for the preparation C 3,4-diphosphoryl furans and 4-monophosphoryl under conditions with no added transition metals is disclosed.

Language: Английский

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Engineered Nanoporous Frameworks for Adsorption Cooling Applications

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(12), P. 7619 - 7673

Published: April 29, 2024

The energy demand for traditional vapor-compressed technology space cooling continues to soar year after due global warming and the increasing human population's need improve living working conditions. Thus, there is a growing eco-friendly technologies that use sustainable or waste resources. This review discusses properties of various refrigerants used adsorption applications followed by brief discussion on thermodynamic cycle. Next, sorbents traditionally are reviewed emphasize advanced capture materials with superior refrigerant sorption. remainder focus studies using engineered nanoporous frameworks (ENFs) applications. effects factors play role in ENF–refrigerant pair selection, including pore structure/dimension/shape, morphology, open-metal sites, chemistry possible presence defects, reviewed. in-depth insights into sorbent–refrigerant interaction, filling mechanism gained through combination characterization techniques computational modeling discussed. Finally, we outline challenges opportunities related ENFs provide our views future this technology.

Language: Английский

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Nickel-catalyzed reductive cross-coupling of polyfluoroarenes with alkyl electrophiles by site-selective C–F bond activation

Chinese Chemical Letters, Journal Year: 2022, Volume and Issue: 33(9), P. 4287 - 4292

Published: Feb. 3, 2022

Language: Английский

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Nickel-Catalyzed Functionalization Reactions Involving C–H Bond Activation via an Amidate-Promoted Strategy and Its Extension to the Activation of C–F, C–O, C–S, and C–CN Bonds

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(21), P. 3053 - 3064

Published: Oct. 11, 2023

ConspectusThe development of functionalization reactions involving the activation C-H bonds has evolved extensively due to atom and step economy associated with such reactions. Among these reactions, chelation assistance been shown provide a powerful solution serious issues reactivity regioselectivity faced in bonds. The vast majority reported thus far involved use precious metals. Kleiman Dubeck cyclonickelation azobenzene NiCp2 which an azo group directs Ni center activate ortho bond close proximity. Although this stoichiometric reaction was discovered earlier than that for other transition-metal complexes, its as catalytic delayed. No general systems were available Ni-catalyzed long time. This Account details our group's Ni(0)- Ni(II)-catalyzed chelation-assisted It also highlights how new strategy can be extended unreactive bonds.In early 2010s, we found Ni(0)-catalyzed aromatic amides contain 2-pyridinylmethylamine moiety directing alkynes results C-H/N-H oxidative annulation give isoquinolinones. In addition, combination Ni(II) catalyst 8-aminoquinoline superior developing wide variety various electrophiles. proposed include formation unstable Ni(IV) and/or Ni(III) species; generation high-valence species rare at time, but since then, many papers dealing DFT organometallic studies have appeared literature attempts understand mechanism. Based on in-depth considerations mechanism respect why N,N-bidentate is required, realized N-Ni by addition N-H Ni(0) or ligand exchange between key step. We concluded precoordination N(sp2) positions proximity permits bond. working hypothesis, carried out using KOtBu base do not specific desired isoquinolinone, amidate anion acts actual group. Remarkably, applicable C-F, C-O, C-S, C-CN.

Language: Английский

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Transition-metal-catalyzed asymmetric defluorinative reactions

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(15), P. 3909 - 3928

Published: Jan. 1, 2023

The latest achievements in transition-metal-catalyzed enantioselective defluorinative coupling reactions have been comprehensively summarized on the basis of classification transition-metal catalysts.

Language: Английский

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