Radical Carboxylative Cyclizations and Carboxylations with CO₂

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(10), P. 2518 - 2531

Published: May 6, 2021

ConspectusCarbon dioxide (CO2) is not only a greenhouse gas and common waste product but also an inexpensive, readily available, renewable carbon resource. It important one-carbon (C1) building block in organic synthesis for the construction of valuable compounds. However, its utilization challenging owing to thermodynamic stability kinetic inertness. Although significant progress has been achieved, many limitations remain this field with regard substrate scope, reaction system, activation strategies.Since 2015, our group focused on CO2 synthesis. We are interested vast possibilities radical chemistry, although high reactivity radicals presents challenges controlling selectivity. hope develop highly useful transformations involving by achieving balance selectivity under mild conditions. Over past 6 years, we along other experts have disclosed radical-type carboxylative cyclizations carboxylations using CO2.We initiated research realizing Cu-catalyzed oxytrifluoromethylation allylamines heteroaryl methylamines generate 2-oxazolidones various precursors. Apart from Cu catalysis, visible-light photoredox catalysis powerful method achieve efficient cyclization. In these cases, single-electron-oxidation-promoted C–O bond formation between benzylic carbamates key step.Since carboxylic acids exist widely natural products bioactive drugs serve as bulk chemicals industry, realized further visible-light-promoted construct such chemicals. achieved selective umpolung imines, enamides, tetraalkylammonium salts, oxime esters successive single-electron-transfer (SSET) reduction. Using strategy, dearomative arylcarboxylation indoles CO2. addition incorporation 1 equiv per substrate, recently developed photoredox-catalyzed dicarboxylation alkenes, allenes, (hetero)arenes via SSET reduction, which allows two molecules into compounds diacids polymer precursors.In two-electron CO2, sought new strategies realize single-electron Inspired hypothetical electron-transfer mechanism iron–sulfur proteins, visible-light-driven thiocarboxylation alkenes catalytic iron salts promoters. The in-situ-generated Fe/S complexes likely able reduce anion, could react give stabilized radical. Moreover, charge-transfer complex (CTC) thiolate acrylate/styrene hydrocarboxylation generation or alkene anion. On basis novel CTC, organocatalytic Hantzsch ester effective reductant.

Language: Английский

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Direct decarboxylative Giese reactions

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(4), P. 1415 - 1453

Published: Jan. 1, 2022

This review summarizes recent progress on using carboxylic acids directly as convenient precursors for the 1,4-radical conjugate addition (Giese) reaction.

Language: Английский

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Boryl Radical Activation of Benzylic C–OH Bond: Cross-Electrophile Coupling of Free Alcohols and CO₂ via Photoredox Catalysis

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

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Free Carboxylic Acids: The Trend of Radical Decarboxylative Functionalization

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(21)

Published: April 7, 2023

Abstract The exceptional versatility of carboxylic acids has been extensively exploited in organic synthesis across several decades. There a recent upsurge radical decarboxylative transformations. process can be initiated under mild conditions, and the resultant radicals have orthogonal reactivities to closed‐shell species, thus providing immense opportunities for streamlining novel reactions. use free is most desirable owing its high atom step economy. Aiming demonstrate attractiveness strategy inspire chemists tackle existing challenges, this review outlines advances on functionalization acids.

Language: Английский

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Arylcarboxylation of unactivated alkenes with CO2 via visible-light photoredox catalysis

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

Published: June 14, 2023

Photocatalytic carboxylation of alkenes with CO2 is a promising and sustainable strategy to synthesize high value-added carboxylic acids. However, it challenging rarely investigated for unactivated due their low reactivities. Herein, we report visible-light photoredox-catalyzed arylcarboxylation CO2, delivering variety tetrahydronaphthalen-1-ylacetic acids, indan-1-ylacetic indolin-3-ylacetic chroman-4-ylacetic acids thiochroman-4-ylacetic in moderate-to-good yields. This reaction features chemo- regio-selectivities, mild conditions (1 atm, room temperature), broad substrate scope, good functional group compatibility, easy scalability facile derivatization products. Mechanistic studies indicate that situ generation carbon dioxide radical anion following addition might be involved the process.

Language: Английский

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Photocatalytic Carboxylation of C−N Bonds in Cyclic Amines with CO₂ by Consecutive Visible‐Light‐Induced Electron Transfer

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(11)

Published: Jan. 21, 2023

Abstract Visible‐light photocatalytic carboxylation with CO 2 is highly important. However, it still remains challenging for reluctant substrates low reduction potentials. Herein, we report a novel of C−N bonds in cyclic amines via consecutive photo‐induced electron transfer (ConPET). It also the first reductive ring‐opening reaction azetidines, pyrrolidines and piperidines. This strategy practical to transform variety easily available valuable β‐, γ‐, δ‐ ϵ‐amino acids moderate‐to‐excellent yields. Moreover, method features mild transition‐metal‐free conditions, high selectivity, good functional‐group tolerance, facile scalability product derivations. Mechanistic studies indicate that ConPET might be key generating reactive photocatalysts, which enable activation generate carbon radicals carbanions as intermediates.

Language: Английский

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Tandem Dual-Site PbCu Electrocatalyst for High-Rate and Selective Glycine Synthesis at Industrial Current Densities

Nano Letters, Journal Year: 2024, Volume and Issue: 24(7), P. 2392 - 2399

Published: Feb. 9, 2024

Direct electrosynthesis of high-value amino acids from carbon and nitrogen monomers remains a challenge. Here, we design tandem dual-site PbCu electrocatalyst for efficient acid electrosynthesis. Using oxalic (H2C2O4) hydroxylamine (NH2OH) as the raw reactants, first time, have realized flow-electrosynthesis glycine at industrial current density 200 mA cm–2 with Faradaic efficiency over 78%. In situ ATR-FTIR spectroscopy characterizations reveal favorable pathway on catalyst. Specifically, Pb site drives highly selective electroreduction H2C2O4 to form glyoxylic acid, Cu accelerates fast hydrogenation oxime product. A (GES)-formaldehyde electrooxidation (FOR) assembly is further established, which synthesizes more valuable chemicals (HCOOH, H2) while minimizing energy consumption. Altogether, introduce new strategy enable one-step widely accessible monomers.

Language: Английский

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Visible-Light Photoredox-Catalyzed Intermolecular α-Aminomethyl/Carboxylative Dearomatization of Indoles with CO₂ and α-Aminoalkyl Radical Precursors

Organic Letters, Journal Year: 2024, Volume and Issue: 26(2), P. 467 - 472

Published: Jan. 5, 2024

Disclosed here is a visible-light photoredox-catalyzed intermolecular sequential α-aminomethyl/carboxylative dearomatization of indoles with CO2 and α-aminoalkyl radical precursors, affording series functionalized indoline-3-carboxylic acids lactams in good yields high regioselectivity. This multicomponent reaction provides green facile method for the synthesis diverse indolines by using as carboxylic carbonyl source.

Language: Английский

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Recent progress and challenges in carboxylation with CO2

Current Opinion in Green and Sustainable Chemistry, Journal Year: 2021, Volume and Issue: 32, P. 100525 - 100525

Published: June 8, 2021

Language: Английский

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Visible-Light Photoredox-Catalyzed Carboxylation of Activated C(sp³)─O Bonds with CO₂

ACS Catalysis, Journal Year: 2021, Volume and Issue: 12(1), P. 18 - 24

Published: Dec. 9, 2021

The photocatalytic carboxylation with CO2 has emerged as an efficient way to afford valuable aliphatic carboxylic acids. However, the difficultly available starting materials, limited substrate scope, and/or use of high loading transition-metal catalysts hamper their wide application. In contrast, alcohols and derivatives, which are environmentally benign readily in nature industry, have rarely been investigated such a process. Herein, we report visible-light photoredox-catalyzed activated C(sp3)─O bonds under mild transition-metal-free conditions. A variety benzyl bearing primary, secondary, more challenging tertiary bonds, undergo CO2, generating aryl acetic acids, ibuprofen, naproxen, fenoprofen, flurbiprofen, broad scope good functional group tolerance. Moreover, this strategy is also applicable other carboxylates α-hydroxyl amides, esters, nitriles, well allyl alcohols, representing practical method for acid synthesis.

Language: Английский

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