Recent Advances in C—F Bond Formation from Carbon‐Centered Radicals DOI

Jihua Zhang,

Sheng Wang, Qiang Cheng

и другие.

Chinese Journal of Chemistry, Год журнала: 2023, Номер 42(9), С. 1009 - 1031

Опубликована: Дек. 8, 2023

Comprehensive Summary Construction of C—F bonds is a direct and efficient method for introducing fluorine into pharmaceuticals, agrochemicals, materials. Strategies such as nucleophilic, electrophilic, radical, transition‐metal catalyzed fluorination have been developed to meet the demand diverse bond formation. Among them, radical has witnessed with substantial advancement in recent decade. Herein, we reviewed methods formation carbon‐centered radicals key intermediates, especially five years. We introduce paper different fluorinating reagents, strategies generation, application late‐stage functionalization synthesis PET tracers. also indicate current limitations propose direction field future development. Key Scientists Radical was recognized an old uncontrolled reaction that may date back time when element first mixed organic compounds by Henri Moissan 1891. The development slow combination discovery new reagents. Substantial changes took place 2012, example carbon robust mild NFSI Selectfluor, reported Sammis group. In same year, Groves, Lectka, Li, Boger led pioneering works on aliphatic C—H fluorination, decarboxylative fluorofunctionalization alkenes manner. Photoredox catalysis introduced 2013 Chen group, which opens up avenue fluorinative transformations. Most previous focus form C(sp 3 )–F bonds. 2018, challenging non‐directed aromatic solved Ritter coworkers. Direct arene fluoride ion later disclosed Nicewicz group 2019. There are many other scientists made tremendous contribution too limited space list them all. only those discoveries point fluorination.

Язык: Английский

Photocatalytic Late-Stage C–H Functionalization DOI
Peter Bellotti, Huan‐Ming Huang,

Teresa Faber

и другие.

Chemical Reviews, Год журнала: 2023, Номер 123(8), С. 4237 - 4352

Опубликована: Янв. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Язык: Английский

Процитировано

334
Radical C(sp3)–H functionalization and cross-coupling reactions DOI
Dung L. Golden, Sung‐Eun Suh, Shannon S. Stahl

и другие.

Nature Reviews Chemistry, Год журнала: 2022, Номер 6(6), С. 405 - 427

Опубликована: Май 17, 2022

Язык: Английский

Процитировано

194
Strategies for Nucleophilic C(sp3)–(Radio)Fluorination DOI
Isabelle Nathalie-Marie Leibler, Shivaani Gandhi, Makeda A. Tekle‐Smith

и другие.

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(18), С. 9928 - 9950

Опубликована: Апрель 24, 2023

This Perspective surveys the progress and current limitations of nucleophilic fluorination methodologies. Despite long rich history C(sp3)–F bond construction in chemical research, inherent challenges associated with this transformation have largely constrained to a privileged reaction platform. In recent years, Doyle group─along many others─has pursued study development intent generating deeper mechanistic understanding, developing user-friendly reagents, contributing invention synthetic methods capable enabling radiofluorination. Studies from our laboratory are discussed along developments others field. Fluoride reagent implications identity highlighted. We also outline space inaccessible by technologies series future directions field that can potentially fill existing dark spaces.

Язык: Английский

Процитировано

51
Azolation of Benzylic C–H Bonds via Photoredox-Catalyzed Carbocation Generation DOI
Mrinmoy Das,

Leila Zamani,

Christopher Bratcher

и другие.

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(7), С. 3861 - 3868

Опубликована: Фев. 9, 2023

A visible-light photoredox-catalyzed method is reported that enables the coupling between benzylic C-H substrates and N-H azoles. Classically, medicinally relevant

Язык: Английский

Процитировано

42
A General Photocatalytic Strategy for Nucleophilic Amination of Primary and Secondary Benzylic C–H Bonds DOI
Madeline E. Ruos, R. Garrison Kinney, Oliver T. Ring

и другие.

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(33), С. 18487 - 18496

Опубликована: Авг. 11, 2023

We report a visible-light photoredox-catalyzed method that enables nucleophilic amination of primary and secondary benzylic C(sp3)-H bonds. A novel amidyl radical precursor organic photocatalyst operate in tandem to transform bonds into carbocations via sequential hydrogen atom transfer (HAT) oxidative radical-polar crossover. The resulting carbocation can be intercepted by variety N-centered nucleophiles, including nitriles (Ritter reaction), amides, carbamates, sulfonamides, azoles, for the construction pharmaceutically relevant C(sp3)-N under unified reaction conditions. Mechanistic studies indicate HAT is radical-mediated operates reductive quenching pathway. These findings establish mild, metal-free, modular protocol rapid diversification library aminated products.

Язык: Английский

Процитировано

35
Enantioselective Intermolecular Radical Amidation and Amination of Benzylic C−H Bonds via Dual Copper and Photocatalysis DOI Creative Commons
Xuemeng Chen, Zhong Lian, Søren Kramer

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(13)

Опубликована: Фев. 1, 2023

A method for direct access to enantioenriched benzylic amides and carbamate-protected primary benzylamines by C-H functionalization is reported. The substrate used as limiting reagent with only a small excess of the unactivated amide or carbamate nucleophile. enantioselective intermolecular dehydrogenative C-N bond formation enabled combination chiral copper catalyst, photocatalyst, an oxidant, it takes place under mild conditions, which allow broad scope. compatible late-stage functionalization, provides easy 15 N-labeled amines starting from cheap NH4 Cl.

Язык: Английский

Процитировано

33
Recent Advances in C–H Functionalisation through Indirect Hydrogen Atom Transfer DOI Creative Commons
Filip S. Meger, John A. Murphy

Molecules, Год журнала: 2023, Номер 28(16), С. 6127 - 6127

Опубликована: Авг. 18, 2023

The functionalisation of C–H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple equivalents for synthons. Hydrogen atom transfer (HAT) is a key method forming alkyl radicals from substrates. Classic reactions, including the Barton nitrite ester reaction Hofmann–Löffler–Freytag reaction, among others, provided early examples HAT. However, recent developments photoredox catalysis electrochemistry have made HAT powerful tool capable introducing wide range functional groups into bonds. Moreover, greater mechanistic insights stimulated development increasingly site-selective protocols. Site-selectivity can be achieved through tuning electron density at certain using additives, judicious choice reagent, solvent system. Herein, we describe latest methods functionalizing C–H/Si–H/Ge–H indirect between 2018–2023, as well critical discussion reagents, aspects, substrate scopes, background contexts

Язык: Английский

Процитировано

29
Copper-catalyzed electrochemical C–H fluorination DOI Creative Commons
Heather A. Hintz, Jamey K. Bower, Jinghua Tang

и другие.

Chem Catalysis, Год журнала: 2023, Номер 3(1), С. 100491 - 100491

Опубликована: Янв. 1, 2023

We report the systematic development of an electrooxidative methodology that translates stoichiometric C–H fluorination reactivity isolable CuIII fluoride complex into a catalytic process. The critical challenges electrocatalysis with highly reactive species are addressed by judicious selection electrolyte, F− source, and sacrificial electron acceptor. Catalyst-controlled occurs preference for hydridic bonds high bond-dissociation energies over weaker but less bonds. selectivity is driven oxidative asynchronous proton-coupled transfer (PCET) at electrophilic CuIII–F complex. further demonstrate asynchronicity factor hydrogen-atom transfer, η, can be used as guideline to rationalize fluorination.

Язык: Английский

Процитировано

24
Transition-metal-free regioselective and stereoselective C(sp2)–C(sp3) coupling of enamides with ethers or alkanes via photoredox-catalyzed cross-dehydrogenative coupling reactions DOI

Ji‐Yu Tao,

Yingxue Wang, Qinghong Zhang

и другие.

Green Chemistry, Год журнала: 2022, Номер 24(10), С. 4004 - 4011

Опубликована: Янв. 1, 2022

A regio- and stereoselective C(sp 2 )–C(sp 3 ) coupling of enamides with ethers or alkanes via photoredox-catalyzed cross-dehydrogenative reactions is developed under environmentally friendly conditions.

Язык: Английский

Процитировано

33
Radical Redox Annulations: A General Light-Driven Method for the Synthesis of Saturated Heterocycles DOI Creative Commons
Philip R. D. Murray, Isabelle Nathalie-Marie Leibler, Sandrine M. Hell

и другие.

ACS Catalysis, Год журнала: 2022, Номер 12(21), С. 13732 - 13740

Опубликована: Окт. 26, 2022

We introduce here a two-component annulation strategy that provides access to diverse collection of five- and six-membered saturated heterocycles from aryl alkenes family redox-active radical precursors bearing tethered nucleophiles. This transformation is mediated by combination an Ir(III) photocatalyst Brønsted acid under visible-light irradiation. A reductive proton-coupled electron transfer generates reactive which undergoes addition alkene. Then, oxidative radical-polar crossover step leading carbocation formation followed ring closure through cyclization the nucleophile. wide range are easily accessible, including pyrrolidines, piperidines, tetrahydrofurans, morpholines, δ-valerolactones, dioxanones. demonstrate scope this approach broad structural variation both reaction components. method amenable gram-scale preparation complex fragment coupling.

Язык: Английский

Процитировано

29