Visible Light-Driven Radical-Mediated C–C Bond Cleavage/Functionalization in Organic Synthesis

Chemical Reviews, Год журнала: 2020, Номер 121(1), С. 506 - 561

Опубликована: Май 29, 2020

Thermal C–C bond cleavage reactions allow the construction of structurally diverse molecular skeletons via predictable and efficient reorganizations. Visible light photoredox-catalyzed radical-mediated have recently emerged as a powerful alternative method for overcoming thermodynamic kinetic barrier in scaffolds. In recent years, plethora elegant useful been invented, products are sometimes otherwise inaccessible by classic thermal reactions. Considering great influence synthetic potential these reactions, we provide summary state art visible light-driven cleavage/functionalization strategies with specific emphasis on working models. We hoped that this review will be medicinal organic chemists inspire further reaction development interesting area.

Язык: Английский

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Asymmetric three-component olefin dicarbofunctionalization enabled by photoredox and copper dual catalysis

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Март 22, 2021

Abstract The intermolecular three-component alkene vicinal dicarbofunctionalization (DCF) reaction allows installation of two different carbon fragments. Despite extensive investigation into its ionic chemistry, the enantioseletive radical-mediated versions DCF reactions remain largely unexplored. Herein, we report an intermolecular, enantioselective radical olefins enabled by merger addition and cross-coupling using photoredox copper dual catalysis. Key to success this protocol relies on chemoselective acyl cyanoalkyl radicals, generated in situ from redox-active oxime esters a photocatalytic N-centered iminyl radical-triggered C-C bond cleavage event, onto alkenes form new radicals. Single electron metalation such newly formed radicals TMSCN-derived L1 Cu(II)(CN) 2 complex leads asymmetric cross-coupling. This process proceeds under mild conditions, tolerates diverse range functionalities synthetic handles, leading valuable optically active β –cyano ketones alkyldinitriles, respectively, highly manner (>60 examples, up 97% ee).

Язык: Английский

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Reactivity of oximes for diverse methodologies and synthetic applications

Nature Synthesis, Год журнала: 2022, Номер 1(1), С. 24 - 36

Опубликована: Янв. 12, 2022

Язык: Английский

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Selective C-C Bond Scission of Ketones via Visible-Light-Mediated Cerium Catalysis

Chem, Год журнала: 2019, Номер 6(1), С. 266 - 279

Опубликована: Дек. 9, 2019

Язык: Английский

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Reactivity Tuning for Radical–Radical Cross-Coupling via Selective Photocatalytic Energy Transfer: Access to Amine Building Blocks

ACS Catalysis, Год журнала: 2019, Номер 9(11), С. 10454 - 10463

Опубликована: Окт. 8, 2019

Reductive N–O bond cleavage has been widely explored for providing either N or O radical species various coupling processes. Despite significant advances, this photoredox pathway is less appealing due to poor atom economy owing the loss of one fragment during transformation. In regard, homolytic by an energy-transfer provide two key radicals would be highly desirable overcoming limitations use fragment. We report exclusive approach development a challenging radical–radical C(sp3)–N cross-coupling process reactivity-tuning catalytic system. The oxime esters in presence Ir complex produces acyloxy and iminyl radicals, which undergo decarboxylative yield valuable imines (typically 0.25 mol % cat. 1 h reaction time). Extensive photophysical electrochemical measurements, as well density functional theory studies, were carried out probe mechanism operation Dexter-type was revealed. choice solvent (EtOAc) concentration critical achieving selectivity reactivity process. synthetic utility method studying functionalized esters, including derivatives biologically active natural products drug molecules. Furthermore, situ transformations imine into pharmaceutically important amines also demonstrated, showcasing amine building blocks.

Язык: Английский

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Direct Use of Carboxylic Acids in the Photocatalytic Hydroacylation of Styrenes To Generate Dialkyl Ketones

Organic Letters, Год журнала: 2019, Номер 21(24), С. 9940 - 9944

Опубликована: Ноя. 21, 2019

A general protocol for the hydroacylation of styrenes from aliphatic carboxylic acids is reported. These reactions proceed via β-scission a phosphoranyl radical that accessed by photoredox catalysis, followed addition resulting acyl to styrenyl olefin. We show phosphine tunability critical efficient intermolecular coupling due competitive quenching photocatalyst Primary, secondary, and structurally rigid tertiary all generate valuable unsymmetrical dialkyl ketones.

Язык: Английский

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Oxime‐Derived Iminyl Radicals in Selective Processes of Hydrogen Atom Transfer and Addition to Carbon‐Carbon π‐Bonds

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 363(10), С. 2502 - 2528

Опубликована: Март 25, 2021

Abstract Oximes represent one of the fundamental organic compound classes with a wide range synthetic applications. In last decade O ‐substituted oximes were recognized as synthetically available and versatile precursors iminyl radicals via one‐electron oxidation or reduction employing visible light photoredox catalysts, salts abundant metals (such Cu Fe), other convenient reagents. Iminyl are powerful synthons for various processes cyclization, ring‐opening, CH‐functionalization, coupling. The present review is focused on methods based oxime‐derived developed in few years excluding ring opening reactions cyclic that summarized recent publications. consists two main parts: (1) involving 1,n‐hydrogen atom transfer (n=5 most cases) (2) addition radical to carbon‐carbon π‐bond. magnified image

Язык: Английский

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Alkyl Radical Generation from Alkylboronic Pinacol Esters through Substitution with Aminyl Radicals

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(16), С. 8770 - 8775

Опубликована: Апрель 14, 2023

Alkylboronic pinacol esters (APEs) are highly versatile reagents in organic synthesis. However, the direct generation of alkyl radicals from commonly used, bench-stable APEs has not been well explored. In this communication, radical through reaction with aminyl is reported. The readily generated by visible-light-induced homolytic cleavage N-N bond N-nitrosamines, and C occurs nucleohomolytic substitution at boron. As an application, efficient photochemical alkyloximation alkenes N-nitrosamines under mild conditions presented. A wide range primary, secondary, tertiary engage transformation that easily scaled up.

Язык: Английский

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Visible‐Light‐Promoted Cascade Radical Cyclization: Synthesis of 1,4‐Diketones Containing Chroman‐4‐One Skeletons

Chemistry - An Asian Journal, Год журнала: 2019, Номер 14(19), С. 3269 - 3273

Опубликована: Авг. 29, 2019

Abstract A visible‐light‐induced cascade radical cyclization of aroyl chlorides with 2‐(allyloxy)‐benzaldehyde derivatives has been developed. The method takes advantages unactivated C=C bonds as the acyl acceptors and offers a mild green approach for synthesis 1,4‐diketones bearing biologically important chroman‐4‐one skeletons moderate to good yields.

Язык: Английский

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Synthesis of (E)-Quinoxalinone Oximes through a Multicomponent Reaction under Mild Conditions

Organic Letters, Год журнала: 2020, Номер 23(1), С. 195 - 201

Опубликована: Дек. 23, 2020

Herein, a novel method for the gram-scale synthesis of (E)-quinoxalinone oximes through multicomponent reaction under mild conditions is described. Such transformation was performed transition-metal-free conditions, affording (E)-oximes in moderate-to-good yield recrystallization. Our methodology demonstrates successful combination Mannich-type and radical coupling, providing green practical approach potentially bioactive quinoxalinone-containing molecules.

Язык: Английский

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