Direct Decarboxylation of Trifluoroacetates Enabled by Iron Photocatalysis** DOI Creative Commons
Sara Fernández‐García, Veronika O. Chantzakou, Francisco Juliá‐Hernández

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(5)

Published: Dec. 13, 2023

Trifluoroacetates are the most abundant and accessible sources of trifluoromethyl groups, which key components in pharmaceuticals agrochemicals. The generation reactive radicals from trifluoroacetates requires their decarboxylation, is hampered by high oxidation potential. This constitutes a major challenge for redox-based methods, because need to pair redox potentials with trifluoroacetate. Here we report strategy based on iron photocatalysis promote direct photodecarboxylation that displays reactivity features escape limitations. Our synthetic design has enabled use trifluoromethylation more easily oxidizable organic substrates, offering new opportunities late-stage derivatization campaigns using chemical feedstocks, Earth-abundant catalysts, visible-light.

Language: Английский

Direct excitation strategy for radical generation in organic synthesis DOI
Yuto Sumida, Hirohisa Ohmiya

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(11), P. 6320 - 6332

Published: Jan. 1, 2021

This tutorial review encompasses the radical generation based on classical methods and photoredox catalysis. It will also focus only demanding visible-light, which involves EDA complex direct photo-excitation strategy.

Language: Английский

Citations

151
Recent advances in radical chemistry proceeding through pro-aromatic radicals DOI Creative Commons
Anup Bhunia, Armido Studer

Chem, Journal Year: 2021, Volume and Issue: 7(8), P. 2060 - 2100

Published: April 21, 2021

Language: Английский

Citations

109
Electrophotocatalytic C−H Heterofunctionalization of Arenes DOI
He Huang, Tristan H. Lambert

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(20), P. 11163 - 11167

Published: March 4, 2021

The electrophotocatalytic heterofunctionalization of arenes is described. Using 2,3-dichloro-5,6-dicyanoquinone (DDQ) under a mild electrochemical potential with visible-light irradiation, undergo oxidant-free hydroxylation, alkoxylation, and amination high chemoselectivity. In addition to batch reactions, an recirculating flow process demonstrated, enabling the conversion benzene phenol on gram scale.

Language: Английский

Citations

108
Photoinduced Oxygen Transfer Using Nitroarenes for the Anaerobic Cleavage of Alkenes DOI
Dan E. Wise, Emma Gogarnoiu,

Alana Duke

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(34), P. 15437 - 15442

Published: Aug. 5, 2022

Herein we report the anaerobic cleavage of alkenes into carbonyl compounds using nitroarenes as oxygen transfer reagents under visible light. This approach serves a safe and practical alternative to mainstream oxidative protocols, such ozonolysis Lemieux–Johnson reaction. A wide range possessing oxidatively sensitive functionalities underwent generate derivatives with high efficiency regioselectivity. Mechanistic studies support that transformation occurs via direct photoexcitation nitroarene followed by nonstereospecific radical cycloaddition event alkenes. leads 1,3,2- 1,4,2-dioxazolidine intermediates fragment give products. combination clock experiments in situ photoNMR spectroscopy revealed identities key species putative aryl dioxazolidine intermediates, respectively.

Language: Английский

Citations

93
Halogen-atom and group transfer reactivity enabled by hydrogen tunneling DOI
Timothée Constantin, Bartosz Górski, Michael J. Tilby

et al.

Science, Journal Year: 2022, Volume and Issue: 377(6612), P. 1323 - 1328

Published: Sept. 15, 2022

The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin silicon reagents that maximize the interplay enthalpic (thermodynamic) polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled quantum mechanical tunneling uses cyclohexadiene derivative γ-terpinene as abstractor under mild photochemical conditions. This protocol activates alkyl aryl halides well several alcohol thiol derivatives. Experimental computational studies unveiled noncanonical pathway whereby cyclohexadienyl radical undergoes concerted aromatization or abstraction through an effective H atom. activation mechanism seemingly thermodynamically kinetically unfavorable but rendered feasible tunneling.

Language: Английский

Citations

89
Recent advances in radical-mediated transformations of 1,3-dienes DOI

Peng‐Zi Wang,

Wen‐Jing Xiao, Jia‐Rong Chen

et al.

CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION), Journal Year: 2022, Volume and Issue: 43(3), P. 548 - 557

Published: Feb. 2, 2022

Language: Английский

Citations

81
Photocatalytic C(sp3) radical generationviaC–H, C–C, and C–X bond cleavage DOI Creative Commons
Chia‐Yu Huang, Jianbin Li, Chao‐Jun Li

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5465 - 5504

Published: Jan. 1, 2022

C(sp 3 ) radicals (R˙) are of broad research interest and synthetic utility.

Language: Английский

Citations

75
Lewis Base–Boryl Radicals Enabled Borylation Reactions and Selective Activation of Carbon–Heteroatom Bonds DOI

Tianyu Peng,

Feng‐Lian Zhang, Yi‐Feng Wang

et al.

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 56(2), P. 169 - 186

Published: Dec. 26, 2022

ConspectusThe past decades have witnessed tremendous progress on radical reactions. However, in comparison with carbon, nitrogen, oxygen, and other main group element centered radicals, the synthetic chemistry of boron radicals was less studied, mainly due to high electron-deficiency instability such 3-center-5-electron species. In 1980s, Roberts co-workers found that coordination a Lewis base (amines or phosphines) center could form 4-center-7-electron boryl (Lewis base-boryl LBRs) are be more stable. only limited applications were developed. 2008, Curran achieved breakthrough discovery N-heterocyclic carbene (NHC) which enable range reduction polymerization Despite these exciting findings, powerful valuable LBRs would expected, given structures reactivities easily modulated, provide ample opportunities discover new this Account, summary our key contributions LBR-enabled borylation reactions selective activation inert carbon-heteroatom bonds will presented.Organoboron compounds shown versatile chemical society, their syntheses rely principally ionic The development mechanistically different allows synthesizing products inaccessible by traditional methods. For purpose, we progressively developed series NHC-boryl mediated chemo-, regio-, stereoselective alkenes alkynes, wide variety structurally diverse organoboron molecules successfully prepared. utility borylated also demonstrated. Furthermore, disclosed photoredox protocol for oxidative generation enabled useful defluoroborylation arylboration reactions.Selective bond is an ideal way convert simple starting materials value-added products, while cleavage bonds, particular chemoselectivity control when multiple identical present similar environments, remains long-standing challenge. We envisaged finely tuning properties might solution address Recently, 4-dimethylaminopyridine (DMAP)-boryl promoted sequential C-F functionalization trifluoroacetic acid derivatives, α-C-F selectively snipped via spin-center shift mechanism. This strategy enables facile conversion abundantly available highly mono- difluorinated molecules. Encouraged finding, further three-step sequence construct all-carbon quaternary centers from trichloromethyl groups, where three C-Cl cleaved rational choice suitable precursors each step. dehydroxylative alkylation α-hydroxy carboxylic derivatives achieved, allowing efficient some biomass platform value products.

Language: Английский

Citations

73
Modular and Facile Access to Chiral α-Aryl Phosphates via Dual Nickel- and Photoredox-Catalyzed Reductive Cross-Coupling DOI

Hepan Wang,

Purui Zheng,

Xiaoqiang Wu

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(9), P. 3989 - 3997

Published: Feb. 22, 2022

Chiral phosphine-containing skeletons are important motifs in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Herein, we report a general modular platform to access α-aryl phosphorus compounds via Ni/photoredox-catalyzed enantioconvergent reductive cross-coupling between α-bromophosphates aryl iodides. This dual catalytic regime exhibited high efficiency good functional group compacity. A wide variety of substrates bearing diverse set groups could be converted into phosphates excellent yields enantioselectivities. The utility the method was also demonstrated by development new phosphine ligand synthesis enzyme inhibitor derivatives. detailed mechanistic studies supported radical chain process revealed unique distinction compared with traditional cross-coupling.

Language: Английский

Citations

71
Boryl Radical Activation of Benzylic C–OH Bond: Cross-Electrophile Coupling of Free Alcohols and CO2 via Photoredox Catalysis DOI
Wen‐Duo Li, Yang Wu, Shijun Li

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8551 - 8559

Published: April 4, 2022

A new strategy for the direct cleavage of C(sp3)-OH bond has been developed via activation free alcohols with neutral diphenyl boryl radical generated from sodium tetraphenylborate under mild visible light photoredox conditions. This verified by cross-electrophile coupling and carbon dioxide synthesis carboxylic acids. Direct transformation a range primary, secondary, tertiary benzyl to acids achieved. Control experiments computational studies indicate that undergoes homolysis bond, generating alkyl radicals. After reducing into anion conditions, following carboxylation CO2 affords product.

Language: Английский

Citations

70