Cobalt-electrocatalytic HAT for functionalization of unsaturated C–C bonds

Nature, Год журнала: 2022, Номер 605(7911), С. 687 - 695

Опубликована: Май 25, 2022

Язык: Английский

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Photocatalytic phosphine-mediated water activation for radical hydrogenation

Nature, Год журнала: 2023, Номер 619(7970), С. 506 - 513

Опубликована: Июнь 28, 2023

Abstract The chemical activation of water would allow this earth-abundant resource to be transferred into value-added compounds, and is a topic keen interest in energy research 1,2 . Here, we demonstrate with photocatalytic phosphine-mediated radical process under mild conditions. This reaction generates metal-free PR 3 –H 2 O cation intermediate, which both hydrogen atoms are used the subsequent transformation through sequential heterolytic (H + ) homolytic • cleavage two O–H bonds. –OH intermediate provides an ideal platform that mimics reactivity ‘free’ atom, can directly closed-shell π systems, such as activated alkenes, unactivated naphthalenes quinoline derivatives. resulting H adduct C radicals eventually reduced by thiol co-catalyst, leading overall transfer hydrogenation system, ending up product. thermodynamic driving force strong P=O bond formed phosphine oxide by-product. Experimental mechanistic studies density functional theory calculations support atom key step process.

Язык: Английский

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Photoinduced Hydrocarboxylation via Thiol-Catalyzed Delivery of Formate Across Activated Alkenes

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(33), С. 13022 - 13028

Опубликована: Авг. 12, 2021

Herein we disclose a new photochemical process to prepare carboxylic acids from formate salts and alkenes. This redox-neutral hydrocarboxylation proceeds in high yields across diverse functionalized alkene substrates with excellent regioselectivity. operationally simple procedure can be readily scaled batch at low photocatalyst loading (0.01% photocatalyst). Furthermore, this reaction leverage commercially available carbon isotologues enable the direct synthesis of isotopically labeled acids. Mechanistic studies support working model involving thiol-catalyzed radical chain wherein atoms are delivered substrate via CO2•– as key reactive intermediate.

Язык: Английский

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Intercepting Hydrogen Evolution with Hydrogen-Atom Transfer: Electron-Initiated Hydrofunctionalization of Alkenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(39), С. 17783 - 17791

Опубликована: Сен. 22, 2022

Hydrogen-atom transfer mediated by earth-abundant transition-metal hydrides (M-Hs) has emerged as a powerful tool in organic synthesis. Current methods to generate M-Hs most frequently rely on oxidatively initiated hydride transfer. Herein, we report reductive approach Co-H, which allows for canonical hydrogen evolution reactions be intercepted hydrogen-atom an alkene. Electroanalytical and spectroscopic studies provided mechanistic insights into the formation reactivity of enabled development two new alkene hydrofunctionalization reactions.

Язык: Английский

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A Triple Photoredox/Cobalt/Brønsted Acid Catalysis Enabling Markovnikov Hydroalkoxylation of Unactivated Alkenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(18), С. 7953 - 7959

Опубликована: Апрель 27, 2022

We demonstrate Markovnikov hydroalkoxylation of unactivated alkenes using alcohols through a triple catalysis consisting photoredox, cobalt, and Brønsted acid catalysts under visible light irradiation. The realizes three key elementary steps in single catalytic cycle: (1) Co(III) hydride generation by photochemical reduction Co(II) followed protonation, (2) metal hydrogen atom transfer (MHAT) hydride, (3) oxidation the alkyl complex to Co(IV). precise control protons electrons allows elimination strong acids external reductants/oxidants that are required conventional methods.

Язык: Английский

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Transition-metal-catalyzed C–H bond alkylation using olefins: recent advances and mechanistic aspects

Chemical Society Reviews, Год журнала: 2022, Номер 51(17), С. 7358 - 7426

Опубликована: Янв. 1, 2022

Transition metal catalysis has contributed immensely to C-C bond formation reactions over the last few decades, and alkylation is no exception. The superiority of such methodologies traditional evident from minimal reaction steps, shorter times, atom economy while also allowing control regio- stereo-selectivity. In particular, hydrocarbonation alkenes grabbed increased attention due its fundamental ability effectively selectively synthesise a wide range industrially pharmaceutically relevant moieties. This review attempts provide scientific viewpoint systematic analysis recent developments in transition-metal-catalyzed various C-H bonds using simple activated olefins. key features mechanistic studies involved these transformations are described briefly.

Язык: Английский

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N-Heterocyclic carbenes as privileged ligands for nickel-catalysed alkene functionalisation

Chemical Society Reviews, Год журнала: 2023, Номер 52(9), С. 2946 - 2991

Опубликована: Янв. 1, 2023

This review discusses the applications of N-heterocyclic carbene ligands and their influence on reactivity selectivity Ni-catalysed alkene functionalisations.

Язык: Английский

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Electrochemical hydrogenation and oxidation of organic species involving water

Nature Reviews Chemistry, Год журнала: 2024, Номер 8(4), С. 277 - 293

Опубликована: Март 25, 2024

Язык: Английский

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Photo‐ and Electrochemical Cobalt Catalysed Hydrogen Atom Transfer for the Hydrofunctionalisation of Alkenes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(41)

Опубликована: Май 15, 2023

Catalytic hydrogen atom transfer from metal-hydrides to alkenes allows feedstock olefins be used as alkyl radical precursors. The chemoselectivity of this process makes it an attractive synthetic tool and such has been regularly in synthesis complex molecules. However, onwards reactivity is limited by compatibility with the conditions which form key metal-hydride species. Now, through merger photocatalysis or electrochemistry, milder methods are emerging can unlock entirely new offer perspectives on expanding these unprecedented directions. This review outlines most recent developments electro- photochemical cobalt catalysed offers suggestions future outlook.

Язык: Английский

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Electrocatalytic Access to Azetidines via Intramolecular Allylic Hydroamination: Scrutinizing Key Oxidation Steps through Electrochemical Kinetic Analysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(28), С. 15360 - 15369

Опубликована: Июль 10, 2023

Azetidines are prominent structural scaffolds in bioactive molecules, medicinal chemistry, and ligand design for transition metals. However, state-of-the-art methods cannot be applied to intramolecular hydroamination of allylic amine derivatives despite their underlying potential as one the most prevalent synthetic precursors azetidines. Herein, we report an electrocatalytic method sulfonamides access azetidines first time. The merger cobalt catalysis electricity enables regioselective generation key carbocationic intermediates, which could directly undergo C-N bond formation. mechanistic investigations including electrochemical kinetic analysis suggest that either catalyst regeneration by nucleophilic cyclization or second oxidation intermediate is involved rate-determining step (RDS) our protocol highlight ability electrochemistry providing ideal means mediate oxidation.

Язык: Английский

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