Synthetic Molecular Photoelectrochemistry: New Frontiers in Synthetic Applications, Mechanistic Insights and Scalability

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(12)

Опубликована: Сен. 3, 2021

Synthetic photoelectrochemistry (PEC) is receiving increasing attention as a new frontier for the generation and handling of reactive intermediates. PEC permits selective single-electron transfer (SET) reactions in much greener way broadens redox window possible transformations. Herein, most recent contributions are reviewed, demonstrating exciting opportunities, namely, combination with other reactivity paradigms (hydrogen-atom transfer, radical polar crossover, energy sensitization), scalability up to multigram scale, novel selectivities SET super-oxidations/reductions importance precomplexation temporally enable excited ion catalysis.

Язык: Английский

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Visible-light photocatalytic di- and hydro-carboxylation of unactivated alkenes with CO2

Nature Catalysis, Год журнала: 2022, Номер 5(9), С. 832 - 838

Опубликована: Сен. 15, 2022

Язык: Английский

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Photochemical C–F Activation Enables Defluorinative Alkylation of Trifluoroacetates and -Acetamides

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(47), С. 19648 - 19654

Опубликована: Ноя. 18, 2021

The installation of gem-difluoromethylene groups into organic structures remains a daunting synthetic challenge despite their attractive structural, physical, and biochemical properties. A very efficient retrosynthetic approach would be the functionalization single C–F bond from trifluoromethyl group. Recent advances in this line attack have enabled activation trifluoromethylarenes, but limit accessible motifs to only benzylic gem-difluorinated scaffolds. In contrast, trifluoroacetates enable use as bifunctional synthon. Herein, we report photochemically mediated method for defluorinative alkylation commodity feedstock: ethyl trifluoroacetate. novel mechanistic was identified using our previously developed diaryl ketone HAT catalyst hydroalkylation diverse suite alkenes. Furthermore, electrochemical studies revealed that more challenging radical precursors, namely trifluoroacetamides, could also functionalized via synergistic Lewis acid/photochemical activation. Finally, concise gem-difluoro analogs FDA-approved pharmaceutical compounds.

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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A general electron donor–acceptor complex for photoactivation of arenes via thianthrenation

Chemical Science, Год журнала: 2022, Номер 13(19), С. 5659 - 5666

Опубликована: Янв. 1, 2022

General photoactivation of EDA complexes between arylsulfonium salts and 1,4-diazabicyclo[2.2.2]octane was discovered. This practical mode enables the generation aryl radicals for C–H functionalization arenes.

Язык: Английский

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The advent and development of organophotoredox catalysis

Chemical Communications, Год журнала: 2021, Номер 58(9), С. 1263 - 1283

Опубликована: Дек. 10, 2021

We herein discuss how and when organic photocatalysts can efficiently replace or outperform their metal counterparts.

Язык: Английский

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Arenethiolate as a Dual Function Catalyst for Photocatalytic Defluoroalkylation and Hydrodefluorination of Trifluoromethyls

ACS Catalysis, Год журнала: 2022, Номер 12(7), С. 4103 - 4109

Опубликована: Март 18, 2022

Thiol is known to act as a hydrogen atom transfer catalyst working in synergy with photocatalyst photoredox catalysis, but we report herein that an arene thiolate appropriate substituent can be photoactivated under visible light function both strongly reducing electron-donating redox and HAT enable catalytic C–F activation of trifluoromethyl substrates for selective hydrodefluorination coupling various alkenes the presence formate salts. These reactions demonstrate promising utility arenethiolates dual photocatalysts. The synthetic this method demonstrated by broad scope amenable substrates, including trifluoromethylated (hetero)arenes, trifluoroacetates, trifluoroacetamides, which exhibited high levels chemoselectivity. reaction efficacy allows site-selective late-stage functionalization multitrifluoromethylated bioactive compounds pharmaceuticals

Язык: Английский

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Photocatalytic defluoroalkylation and hydrodefluorination of trifluoromethyls using o-phosphinophenolate

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Янв. 17, 2022

Under visible light irradiation, o-phosphinophenolate functions as an easily accessible photoredox catalyst to activate trifluoromethyl groups in trifluoroacetamides, trifluoroacetates, and (hetero)arenes deliver corresponding difluoromethyl radicals. It works relay with a thiol hydrogen atom transfer (HAT) enable selective defluoroalkylation hydrodefluorination. The reaction allows for the facile synthesis of broad scope difluoromethylene-incorporated carbonyl (hetero)aromatic compounds, which are valuable fluorinated intermediates interest pharmaceutical industry. ortho-diphenylphosphino substituent, is believed facilitate photoinduced electron transfer, plays essential role redox reactivity phenolate. In addition groups, pentafluoroethyl could also be selectively defluoroalkylated.

Язык: Английский

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Photoredox‐Catalyzed Defluorinative Functionalizations of Polyfluorinated Aliphatic Amides and Esters

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(9)

Опубликована: Дек. 10, 2021

Abstract Selective C−F bond functionalization of perfluoalkyl units has huge potential towards accessing functionalized organofluorinated compounds, but remains challenging due to the high strength and inherent selectivity challenges. We report a new catalytic approach selective strong bonds in polyfluorinated aliphatic esters amides. This simple reaction proceeds mild operational fashion with divergent conversions, including hydrodefluorination, defluoroalkylation, defluoroalkenylation, affording diverse array important partially fluorinated motifs. Straightforward downstream chemistry alcohols, amines drug derivatives highlights protocol.

Язык: Английский

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Halogen-atom and group transfer reactivity enabled by hydrogen tunneling

Science, Год журнала: 2022, Номер 377(6612), С. 1323 - 1328

Опубликована: Сен. 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.

Язык: Английский

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