Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C–H Bonds Elaboration

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1875 - 1924

Published: Aug. 6, 2021

Direct photocatalyzed hydrogen atom transfer (d-HAT) can be considered a method of choice for the elaboration aliphatic C–H bonds. In this manifold, photocatalyst (PCHAT) exploits energy photon to trigger homolytic cleavage such bonds in organic compounds. Selective bond may achieved by judicious abstractor (key parameters are electronic character and molecular structure), as well reaction additives. Different classes PCsHAT available, including aromatic ketones, xanthene dyes (Eosin Y), polyoxometalates, uranyl salts, metal-oxo porphyrin tris(amino)cyclopropenium radical dication. The processes (mainly C–C formation) most cases carried out under mild conditions with help visible light. aim review is offer comprehensive survey synthetic applications d-HAT.

Language: Английский

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Photocatalytic Late-Stage C–H Functionalization

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(8), P. 4237 - 4352

Published: Jan. 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.

Language: Английский

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Radical C(sp3)–H functionalization and cross-coupling reactions

Nature Reviews Chemistry, Journal Year: 2022, Volume and Issue: 6(6), P. 405 - 427

Published: May 17, 2022

Language: Английский

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Automated self-optimization, intensification, and scale-up of photocatalysis in flow

Science, Journal Year: 2024, Volume and Issue: 383(6681)

Published: Jan. 25, 2024

The optimization, intensification, and scale-up of photochemical processes constitute a particular challenge in manufacturing environment geared primarily toward thermal chemistry. In this work, we present versatile flow-based robotic platform to address these challenges through the integration readily available hardware custom software. Our open-source combines liquid handler, syringe pumps, tunable continuous-flow photoreactor, inexpensive Internet Things devices, an in-line benchtop nuclear magnetic resonance spectrometer enable automated, data-rich optimization with closed-loop Bayesian strategy. A user-friendly graphical interface allows chemists without programming or machine learning expertise easily monitor, analyze, improve photocatalytic reactions respect both continuous discrete variables. system's effectiveness was demonstrated by increasing overall reaction yields improving space-time compared those previously reported processes.

Language: Английский

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Electronic control over site-selectivity in hydrogen atom transfer (HAT) based C(sp³)–H functionalization promoted by electrophilic reagents

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(6), P. 2171 - 2223

Published: Jan. 1, 2022

Leveraging on electronic effects in both the substrate and HAT reagent, site-selectivity can be implemented C(sp 3 )–H bond functionalization.

Language: Английский

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Resurgence and advancement of photochemical hydrogen atom transfer processes in selective alkane functionalizations

Chemical Science, Journal Year: 2023, Volume and Issue: 14(25), P. 6841 - 6859

Published: Jan. 1, 2023

The selective functionalization of alkanes has long been recognized as a prominent challenge and an arduous task in organic synthesis. Hydrogen atom transfer (HAT) processes enable the direct generation reactive alkyl radicals from feedstock have successfully employed industrial applications such methane chlorination process,

Language: Английский

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[3+2] Cycloaddition of alkyl aldehydes and alkynes enabled by photoinduced hydrogen atom transfer

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 12, 2022

Abstract [3+2] Cycloaddition is a step- and atom-economic method for the synthesis of five-membered rings. Despite great success 1,3-dipolar cycloadditions, radical annulation alkynes remains formidable challenge. Herein, photoinduced decatungstate-catalyzed cycloaddition various internal using abundant aliphatic aldehydes as three-carbon synthon developed, producing elaborate cyclopentanones in 100% atom economy with excellent site-, regio-, diastereoselectivity under mild conditions. The catalytic cycle consists hydrogen abstraction from aldehydes, addition, 1,5-hydrogen transfer, anti-Baldwin 5-endo-trig cyclization, back abstraction. power this showcased by late-stage elaboration medicinally relevant molecules total or formal (±)-β-cuparenone, (±)-laurokamurene B, (±)-cuparene.

Language: Английский

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Tetrabutylammonium decatungstate (TBADT), a compelling and trailblazing catalyst for visible-light-induced organic photocatalysis

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(19), P. 3799 - 3842

Published: Jan. 1, 2024

Tetrabutylammonium decatungstate (TBADT) has recently emerged as an intriguing photocatalyst under visible-light or near-visible-light irradiation in a wide range of organic reactions that were previously not conceivable. Given its ability to absorb visible light and excellent effectiveness activating unactivated chemical bonds, it is promising addition traditional photocatalysts. This review covers some the contemporary developments photocatalysis enabled by TBADT catalyst 2023, with contents organized reaction type.

Language: Английский

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Unleashing the potentiality of metals: synergistic catalysis with light and electricity

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(14), P. 4024 - 4040

Published: Jan. 1, 2024

This review provides a comprehensive overview of metal catalysis in photo-electrochemical systems, discussing reaction mechanisms and offering prospects for this triadic catalytic mode.

Language: Английский

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Synthesis of Unnatural α-Amino Acid Derivatives via Photoredox Activation of Inert C(sp³)–H Bonds

Organic Letters, Journal Year: 2022, Volume and Issue: 24(26), P. 4793 - 4797

Published: June 24, 2022

The synthesis of unnatural, tertiary amino acids is a challenging task. While decarboxylation-radical addition has been an important strategy for their formation, the use alkyl radicals from C(sp3)-H bonds not fully explored. Herein, we report photocatalytic protocol unnatural α-amino esters employing abundant alkanes and imines retaining full atom economy. When this method applied, several acid derivatives are synthesized in moderate to good yields.

Language: Английский

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