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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Transition-Metal-Catalyzed C–S, C–Se, and C–Te Bond Formations via Cross-Coupling and Atom-Economic Addition Reactions. Achievements and Challenges

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(21), P. 16110 - 16293

Published: Sept. 16, 2022

In the present review, we discuss recent progress in field of C–Z bond formation reactions (Z = S, Se, Te) catalyzed by transition metals. Two complementary methodologies are considered─catalytic cross-coupling and catalytic addition reactions. The development advanced systems is aimed at improved catalyst efficiency, reduced loading, better cost environmental concerns, higher selectivity yields. important rise research efforts sustainability green chemistry areas critically assessed. paramount role mechanistic studies a new generation addressed, key achievements, problems, challenges summarized for this field.

Language: Английский

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Efficient and Direct Functionalization of Allylic sp³ C−H Bonds with Concomitant CO₂ Reduction

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

Published: Aug. 26, 2023

Solar-driven CO2 reduction integrated with C-C/C-X bond-forming organic synthesis represents a substantially untapped opportunity to simultaneously tackle carbon neutrality and create an atom-/redox-economical chemical synthesis. Herein, we demonstrate the first cooperative photoredox catalysis of efficient tunable syngas, paired direct alkylation/arylation unactivated allylic sp3 C-H bonds for accessing C-C products, over SiO2 -supported single Ni atoms-decorated CdS quantum dots (QDs). Our protocol not only bypasses additional oxidant/reductant pre-functionalization substrates, affording broad products moderate excellent yields, but also produces syngas CO/H2 ratios (1 : 2-5 1). Such win-win coupling highlights high atom-, step- redox-economy, good durability, illuminating tantalizing possibility renewable sunlight-driven feedstocks manufacturing industry.

Language: Английский

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Photocatalytic C(sp³) radical generationviaC–H, C–C, and C–X bond cleavage

Chemical Science, Journal Year: 2022, Volume and Issue: 13(19), P. 5465 - 5504

Published: Jan. 1, 2022

C(sp 3 ) radicals (R˙) are of broad research interest and synthetic utility.

Language: Английский

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CdS Quantum Dots as Potent Photoreductants for Organic Chemistry Enabled by Auger Processes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(27), P. 12229 - 12246

Published: June 30, 2022

Strong reducing agents (<−2.0 V vs saturated calomel electrode (SCE)) enable a wide array of useful organic chemistry, but suffer from variety limitations. Stoichiometric metallic reductants such as alkali metals and SmI2 are commonly employed for these reactions; however, considerations including expense, ease use, safety, waste generation limit the practicality methods. Recent approaches utilizing energy multiple photons or electron-primed photoredox catalysis have accessed reduction potentials equivalent to Li0 shown how this enables selective transformations aryl chlorides via radicals. However, in some cases, low stability catalytic intermediates can turnover numbers. Herein, we report ability CdS nanocrystal quantum dots (QDs) function strong photoreductants present evidence that highly electron is generated two consecutive photoexcitations QDs with intermediate reductive quenching. Mechanistic experiments suggest Auger recombination, photophysical phenomenon known occur photoexcited anionic QDs, generates transient thermally excited electrons observed reductions. Using blue light-emitting diodes (LEDs) sacrificial amine reductants, phosphate esters up −3.4 SCE photoreductively cleaved afford hydrodefunctionalized functionalized products. In contrast small-molecule catalysts, stable under conditions numbers 47 500 been achieved. These also effect other challenging reductions, tosylate protecting group removal amines, debenzylation benzyl-protected alcohols, ring opening cyclopropane carboxylic acid derivatives.

Language: Английский

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Semiconductor quantum dots: a versatile platform for photoredox organic transformation

Journal of Materials Chemistry A, Journal Year: 2023, Volume and Issue: 11(7), P. 3262 - 3280

Published: Jan. 1, 2023

A summary of the research progress diverse organic transformations over semiconductor quantum dot based photofunctional catalysts is provided.

Language: Английский

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Radical approaches to C–S bonds

Nature Reviews Chemistry, Journal Year: 2023, Volume and Issue: 7(8), P. 573 - 589

Published: June 21, 2023

Language: Английский

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Heterogeneous Photocatalytic Strategies for C(sp³)−H Activation

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(13)

Published: Jan. 16, 2024

Abstract Activation of ubiquitous C(sp 3 )−H bonds is extremely attractive but remains a great challenge. Heterogeneous photocatalysis offers promising and sustainable approach for activation has been fast developing in the past decade. This Minireview focuses on mechanism strategies heterogeneous photocatalytic activation. After introducing mechanistic insights, including precise design active sites, regulation reactive radical species, improving charge separation reactor innovations are discussed. In addition, recent advances hydrocarbons, alcohols, ethers, amines amides by summarized. Lastly, challenges opportunities outlined to encourage more efforts development this exciting field.

Language: Английский

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Light-activated hypervalent iodine agents enable diverse aliphatic C–H functionalization

Nature Chemistry, Journal Year: 2025, Volume and Issue: 17(3), P. 365 - 372

Published: Feb. 24, 2025

Language: Английский

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Time-Resolved EPR Revealed the Formation, Structure, and Reactivity of N-Centered Radicals in an Electrochemical C(sp³)–H Arylation Reaction

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(49), P. 20863 - 20872

Published: Dec. 1, 2021

Electrochemical synthesis has been rapidly developed over the past few years, while a vast majority of reactions proceed through radical pathway. Understanding properties intermediates is crucial in mechanistic study electrochemical transformations and will be beneficial for developing new reactions. Nevertheless, it rather difficult to determine "live" due their high reactivity. In this work, formation structure sulfonamide N-centered radicals have researched directly by using time-resolved electron paramagnetic resonance (EPR) technique under conditions. Supported EPR results, reactivity as mediator hydrogen atom transfer (HAT) approach discussed. Subsequently, these results successfully utilized discovery an unactivated C(sp3)–H arylation reaction. The kinetic experiments revealed rate-determined step anodic oxidation sulfonamides.

Language: Английский

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