Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1485 - 1542

Published: Nov. 18, 2021

The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox combined unparalleled capacity for bond formation broad utility photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation allowed engagement simple starting materials metal-mediated bond-forming Moreover, electron or energy transfer directly key organometallic intermediates provided novel modes entirely complementary to traditional catalytic platforms. This Review details contextualizes advancements molecule construction brought forth by metallaphotocatalysis.

Language: Английский

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Electrocatalysis as an enabling technology for organic synthesis

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(14), P. 7941 - 8002

Published: Jan. 1, 2021

Electrochemistry has recently gained increased attention as a versatile strategy for achieving challenging transformations at the forefront of synthetic organic chemistry. Electrochemistry's unique ability to generate highly reactive radical and ion intermediates in controlled fashion under mild conditions inspired development number new electrochemical methodologies preparation valuable chemical motifs. Particularly, recent developments electrosynthesis have featured an use redox-active electrocatalysts further enhance control over selective formation downstream reactivity these intermediates. Furthermore, electrocatalytic mediators enable proceed manner that is mechanistically distinct from purely methods, allowing subversion kinetic thermodynamic obstacles encountered conventional synthesis. This review highlights key innovations within past decade area electrocatalysis, with emphasis on mechanisms catalyst design principles underpinning advancements. A host oxidative reductive are discussed grouped according classification transformation nature electrocatalyst.

Language: Английский

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Hydrogen Atom Transfer (HAT): A Versatile Strategy for Substrate Activation in Photocatalyzed Organic Synthesis

European Journal of Organic Chemistry, Journal Year: 2017, Volume and Issue: 2017(15), P. 2056 - 2071

Published: March 2, 2017

The adoption of hydrogen atom transfer (HAT) in a photocatalytic approach, which an excited catalyst is responsible for substrate activation, offers unique opportunities organic synthesis, enabling the straightforward activation R–H (R = C, Si, S) bonds desired reagents. Either direct strategy, based on intrinsic reactivity limited number photocatalysts state, or indirect one, cycle used generation thermal abstractor, can be exploited. This microreview summarizes most recent advances (mainly from last two years) this rapidly developing area research, collecting selected examples according to nature species promoting HAT process. From synthetic point view, has led development plethora strategies C–C, C–Si, C–N, C–S, and C–halogen (particularly, fluorine) bond formation, as well oxidation reactions.

Language: Английский

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Selective functionalization of methane, ethane, and higher alkanes by cerium photocatalysis

Science, Journal Year: 2018, Volume and Issue: 361(6403), P. 668 - 672

Published: July 26, 2018

With the recent soaring production of natural gas, use methane and other light hydrocarbon feedstocks as starting materials in synthetic transformations is becoming increasingly economically attractive, although it remains chemically challenging. We report development photocatalytic C-H amination, alkylation, arylation methane, ethane, higher alkanes under visible irradiation at ambient temperature. High catalytic efficiency (turnover numbers up to 2900 for 9700 ethane) selectivity were achieved using abundant, inexpensive cerium salts photocatalysts. Ligand-to-metal charge transfer excitation generated alkoxy radicals from simple alcohols that turn acted hydrogen atom catalysts. The mixed-phase gas/liquid reaction was adapted continuous flow, enabling efficient gaseous scalable transformations.

Language: Английский

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Complementary Strategies for Directed C(sp³)−H Functionalization: A Comparison of Transition‐Metal‐Catalyzed Activation, Hydrogen Atom Transfer, and Carbene/Nitrene Transfer

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 57(1), P. 62 - 101

Published: Dec. 5, 2017

Abstract The functionalization of C(sp 3 )−H bonds streamlines chemical synthesis by allowing the use simple molecules and providing novel synthetic disconnections. Intensive recent efforts in development new reactions based on C−H have led to its wider adoption across a range research areas. This Review discusses strengths weaknesses three main approaches: transition‐metal‐catalyzed activation, 1, n ‐hydrogen atom transfer, carbene/nitrene for directed unactivated bonds. For each strategy, scope, reactivity different bonds, position reacting relative directing group, stereochemical outcomes are illustrated with examples literature. aim this is provide guidance inspire future area.

Language: Английский

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Photoredox-Mediated Routes to Radicals: The Value of Catalytic Radical Generation in Synthetic Methods Development

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(4), P. 2563 - 2575

Published: March 14, 2017

Photoredox catalysis has experienced a revitalized interest from the synthesis community during past decade. For example, photoredox/Ni dual protocols have been developed to overcome several inherent limitations of palladium-catalyzed cross-couplings by invoking single-electron transmetalation pathway. This Perspective highlights advances made our laboratory since inception cross-coupling benzyltrifluoroborates with aryl bromides. In addition broadening scope trifluoroborate coupling partners, research using readily oxidized hypervalent silicates as radical precursors that demonstrate functional group compatibility is highlighted. The pursuit electrophilic partners beyond (hetero)aryl bromides also led incorporation new classes C(sp2)-hybridized substrates into light-mediated cross-coupling. Advances expand toolbox utilizing feedstock chemicals (e.g., aldehydes) access radicals were previously inaccessible trifluoroborates and are emphasized. Additionally, organic photocatalysts investigated replacements for their expensive iridium- ruthenium-based counterparts. Lastly, net C–H functionalization partner in an effort improve atom economy presented. An underlying theme all these studies value generating catalytic manner, rather than stoichiometrically.

Language: Английский

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Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide

Nature, Journal Year: 2017, Volume and Issue: 545(7652), P. 84 - 88

Published: May 1, 2017

Language: Английский

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Illuminating Photoredox Catalysis

Trends in Chemistry, Journal Year: 2019, Volume and Issue: 1(1), P. 111 - 125

Published: Feb. 23, 2019

Language: Английский

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Remote C–H Functionalization via Selective Hydrogen Atom Transfer

Synthesis, Journal Year: 2018, Volume and Issue: 50(08), P. 1569 - 1586

Published: Feb. 12, 2018

The selective functionalization of remote C–H bonds via intramolecular hydrogen atom transfer (HAT) is transformative for organic synthesis. This radical-mediated strategy provides access to novel reactivity that complementary closed-shell pathways. As modern methods mild generation radicals are continually developed, inherent selectivity paradigms HAT mechanisms offer unparalleled opportunities developing new strategies functionalization. review outlines the history, recent advances, and mechanistic underpinnings as a guide addressing ongoing challenges in this arena. 1 Introduction 2 Nitrogen-Centered Radicals 2.1 sp3 N-Radical Initiation 2.2 sp2 3 Oxygen-Centered 3.1 Carbonyl Diradical 3.2 Alkoxy Radical 3.3 Non-alkoxy 4 Carbon-Centered 4.1 C-Radical 4.2 5 Conclusion

Language: Английский

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Site-Selective C–H Functionalization by Decatungstate Anion Photocatalysis: Synergistic Control by Polar and Steric Effects Expands the Reaction Scope

ACS Catalysis, Journal Year: 2017, Volume and Issue: 8(1), P. 701 - 713

Published: Dec. 5, 2017

The synergistic control of the SH2 transition states hydrogen abstraction by polar and steric effects provides a promising strategy in achieving site-selective C(sp3)–H functionalization under decatungstate anion photocatalysis. By using this photocatalytic approach, C–H bonds alkanes, alcohols, ethers, ketones, amides, esters, nitriles, pyridylalkanes were functionalized site-selectively. In remarkable case 2,4-disubstituted cyclohexanone bearing five methyl, methylene, three methine bonds, one bond isoamyl tether was selectively functionalized.

Language: Английский

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