Electrochemical Late-Stage Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(19), P. 11269 - 11335

Published: Sept. 26, 2023

Late-stage functionalization (LSF) constitutes a powerful strategy for the assembly or diversification of novel molecular entities with improved physicochemical biological activities. LSF can thus greatly accelerate development medicinally relevant compounds, crop protecting agents, and functional materials. Electrochemical synthesis has emerged as an environmentally friendly platform transformation organic compounds. Over past decade, electrochemical late-stage (eLSF) gained major momentum, which is summarized herein up to February 2023.

Language: Английский

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

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(41)

Published: May 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.

Language: 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, Journal Year: 2023, Volume and Issue: 145(28), P. 15360 - 15369

Published: July 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.

Language: Английский

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Electrochemical radical-polar crossover: a radical approach to polar chemistry

Science China Chemistry, Journal Year: 2023, Volume and Issue: 67(2), P. 450 - 470

Published: Nov. 3, 2023

Language: Английский

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Organo‐Mediator Enabled Electrochemical Deuteration of Styrenes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Sept. 12, 2023

Despite widespread use of the deuterium isotope effect, selective labeling chemical molecules remains a major challenge. Herein, facile and general electrochemically driven, organic mediator enabled deuteration styrenes with oxide (D2 O) as economical source was reported. Importantly, this transformation could be suitable for various electron rich mediated by triphenylphosphine (TPP). The reaction proceeded under mild conditions without transition-metal catalysts, affording desired products in good yields excellent D-incorporation (D-inc, up to >99 %). Mechanistic investigations means experiments cyclic voltammetry tests provided sufficient support transformation. Notably, method proved powerful tool late-stage biorelevant compounds.

Language: Английский

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Co-Catalyzed Hydrofluorination of Alkenes: Photocatalytic Method Development and Electroanalytical Mechanistic Investigation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(7), P. 4380 - 4392

Published: Feb. 1, 2024

The hydrofluorination of alkenes represents an attractive strategy for the synthesis aliphatic fluorides. This approach provides a direct means to form C(sp3)–F bonds selectively from readily available alkenes. Nonetheless, conducting using nucleophilic fluorine sources poses significant challenges due low acidity and high toxicity associated with HF poor nucleophilicity fluoride. In this study, we present new Co(salen)-catalyzed simple utilizing Et3N·3HF as sole source both hydrogen fluorine. process operates via photoredox-mediated polar-radical-polar crossover mechanism. We also demonstrated versatility method by effectively converting diverse array activated varying degrees substitution into hydrofluorinated products. Furthermore, successfully applied methodology 18F-hydrofluorination reactions, enabling introduction 18F potential radiopharmaceuticals. Our mechanistic investigations, conducted rotating disk electrode voltammetry DFT calculations, unveiled involvement carbocation CoIV–alkyl species viable intermediates during fluorination step, contribution each pathway depends on structure starting alkene.

Language: Английский

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Carbon–Germanium Bond Formation via Low-Valent Cobalt-Catalyzed Cross-Electrophile Coupling

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(10), P. 6773 - 6780

Published: May 3, 2023

An efficient, electrochemically induced cobalt-catalyzed carbon–germanium bond formation provides access to a variety of functionalized germane-containing compounds, including aryl, vinyl, and alkyl germanes. The germylation is conducted under mild reaction conditions exhibits broad scope functional group tolerance. Mechanistic experimental studies provide insight into the unexpected pathway sequential activation different electrophiles.

Language: Английский

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Cobalt-catalyzed HAT reaction for asymmetric hydrofunctionalization of alkenes and nucleophiles

Chem Catalysis, Journal Year: 2023, Volume and Issue: 3(3), P. 100526 - 100526

Published: Feb. 13, 2023

Language: Английский

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Photoinduced Cobalt Catalysis for the Reductive Coupling of Pyridines and Dienes Enabled by Paired Single‐Electron Transfer**

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Sept. 7, 2023

Abstract Selective hydroarylation of dienes has potential to provide swift access useful building blocks. However, most existing methods rely on stabilised by an aromatic group and transmetallation or nucleophilic attack steps require electron‐rich aryl coupling partners. As such, there are few examples which tolerate wide‐spread heteroarenes such as pyridine. Whilst allylic C−H functionalisation could be considered alternative approach, the positional selectivity unsymmetrical substrates is hard control. Here, we report a general approach for selective hydropyridylation under mild conditions using metal catalysed hydrogen‐atom transfer. Photoinduced, reductive enable simultaneous formation cobalt‐hydride catalyst persistent radical easily‐synthesised pyridyl phosphonium salts. This facilitates in traceless manner at C4‐position wide‐range pyridine substrates. The mildness method underscored its functional‐group tolerance demonstrated applications late‐stage functionalisation. Based combination experimental computational studies, propose mechanistic pathway proceeds through non‐reversible transfer (HAT) from cobalt hydride species uniquely presence other olefins due much higher relative barrier associated with olefin HAT.

Language: Английский

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Metal-free electrochemical dihydroxylation of unactivated alkenes

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 13, 2023

Herein, a metal-free electrochemical dihydroxylation of unactivated alkenes is described. The transformation proceeds smoothly under mild conditions with broad range alkenes, providing valuable and versatile dihydroxylated products in moderate to good yields without the addition costly transition metals stoichiometric amounts chemical oxidants. Moreover, this method can be applied natural pharmaceutical derivatives, further demonstrating its synthetic utility. Mechanistic studies have revealed that iodohydrin epoxide intermediate are formed during reaction process.

Language: Английский

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