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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Photoinduced Remote Functionalisations by Iminyl Radical Promoted C−C and C−H Bond Cleavage Cascades

Angewandte Chemie International Edition, Год журнала: 2017, Номер 57(3), С. 744 - 748

Опубликована: Ноя. 8, 2017

Abstract A photoinduced cascade strategy leading to a variety of differentially functionalised nitriles and ketones has been developed. These reactions rely on the oxidative generation iminyl radicals from simple oximes. Radical transposition by C(sp 3 )−(sp ) )−H bond cleavage gives access distal carbon that undergo S H 2 functionalisations. mild, visible‐light‐mediated procedures can be used for remote fluorination, chlorination, azidation, were applied modification bioactive structurally complex molecules.

Язык: Английский

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A Visible‐Light‐Driven Iminyl Radical‐Mediated C−C Single Bond Cleavage/Radical Addition Cascade of Oxime Esters

Angewandte Chemie International Edition, Год журнала: 2017, Номер 57(3), С. 738 - 743

Опубликована: Дек. 7, 2017

Abstract A room‐temperature, visible‐light‐driven N‐centered iminyl radical‐mediated and redox‐neutral C−C single bond cleavage/radical addition cascade reaction of oxime esters unsaturated systems has been accomplished. The strategy tolerates a wide range O‐acyl oximes systems, such as alkenes, silyl enol ethers, alkynes, isonitrile, enabling highly selective formation various chemical bonds. This method thus provides an efficient approach to diversely substituted cyano‐containing ketones, carbocycles, heterocycles.

Язык: Английский

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Strategies to Generate Nitrogen-centered Radicals That May Rely on Photoredox Catalysis: Development in Reaction Methodology and Applications in Organic Synthesis

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 2353 - 2428

Опубликована: Окт. 8, 2021

For more than 70 years, nitrogen-centered radicals have been recognized as potent synthetic intermediates. This review is a survey designed for use by chemists engaged in target-oriented synthesis. summarizes the recent paradigm shift access to and application of N-centered enabled visible-light photocatalysis. broadens streamlines approaches many small molecules because photocatalysis conditions are mild. Explicit attention paid innovative advances N–X bonds radical precursors, where X = Cl, N, S, O, H. clarity, key mechanistic data noted, available. Synthetic applications limitations summarized illuminate tremendous utility photocatalytically generated radicals.

Язык: Английский

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Cleavage of Carbon–Carbon σ-Bonds of Four-Membered Rings

Chemical Reviews, Год журнала: 2020, Номер 121(1), С. 264 - 299

Опубликована: Сен. 23, 2020

This article reviews synthetic transformations involving cleavage of a carbon-carbon bond four-membered ring, with particular focus on the examples reported during period from 2011 to end 2019. Most significant is progress catalytic reactions oxidative addition bonds onto transition metals or β-carbon elimination metal alkoxides. When they are looked at perspectives, offer unique and efficient methods build complex natural products structures that difficult construct by conventional methods. On other hand, β-scission radical intermediates has also attracted increasing attention as an alternative elementary step cleave bonds. Its site-selectivity often complementary metal-catalyzed reactions. In addition, Lewis acid-mediated thermally induced ring-opening cyclobutanone derivatives garnered renewed attention. whole, these demonstrate potentials structurally strained ring compounds for construction organic skeletons.

Язык: Английский

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Direct C–H Cyanoalkylation of Quinoxalin-2(1H)-ones via Radical C–C Bond Cleavage

Organic Letters, Год журнала: 2018, Номер 20(4), С. 1034 - 1037

Опубликована: Янв. 24, 2018

An efficient synthesis of cyanoalkylated heteroarenes via iron-catalyzed direct C–H cyanoalkylation has been developed. Structurally diverse cyanoalkyl motifs generated through C–C bond cleavage cyclobutanone oxime esters have introduced into quinoxalin-2(1H)-ones, flavone, benzothiazoles, and caffeine in good to excellent yields. Remarkably, less-strained cyclopentanone unstrained cyclohexanone were also amenable substrates this reaction.

Язык: Английский

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Iminyl‐Radicals by Oxidation of α‐Imino‐oxy Acids: Photoredox‐Neutral Alkene Carboimination for the Synthesis of Pyrrolines

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(40), С. 12273 - 12276

Опубликована: Авг. 7, 2017

The visible-light-promoted decarboxylation of α-imino-oxy propionic acids for the generation iminyl radicals has been accomplished through use Ir(dFCF3 ppy)2 (dtbbpy)PF6 as a photoredox catalyst. Different from homolysis and single-electron reduction oxime derivatives, this strategy provides novel catalytic cycle alkene carboimination sequence comprising N-radical generation, radical cyclization, intermolecular conjugate addition to Michael acceptor, afford various pyrroline derivatives in an overall redox-neutral process. indolizidine alkaloid skeleton could be easily constructed derivative prepared by synthetic method.

Язык: Английский

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Radical‐Promoted C−C Bond Cleavage: A Deconstructive Approach for Selective Functionalization

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(40), С. 14044 - 14054

Опубликована: Июнь 6, 2019

Abstract Just as “Deconstructivism” appeared a novel movement in architecture the 1980s, deconstructive approaches have recently emerged excellent strategies for scaffold hopping modifications chemistry. The deconstruction and functionalization of cyclic molecules mainly involves cleavage carbon–carbon (C−C) bond followed by construction new bonds. inert C−C single bonds, especially unstrained cycles, their subsequent is still one most sought‐after challenges In this vein, radical‐mediated provide an approach achieving aim. This minireview outline history homolytic highlights recent advances exploring chemical space functionalization.

Язык: Английский

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Metal-Involving Synthesis and Reactions of Oximes

Chemical Reviews, Год журнала: 2017, Номер 117(21), С. 13039 - 13122

Опубликована: Окт. 9, 2017

This review classifies and summarizes the past 10–15 years of advancements in field metal-involving (i.e., metal-mediated metal-catalyzed) reactions oximes. These are diverse nature have been employed for syntheses oxime-based metal complexes cage-compounds, oxime functionalizations, preparation new classes organic species, particular, a wide variety heterocyclic systems spanning small 3-membered ring to macroheterocycles. consideration gives general outlook reaction routes, mechanisms, driving forces underlines potential conversions species application various fields chemistry draws attention emerging putative targets.

Язык: Английский

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Photocatalytic, Phosphoranyl Radical-Mediated N–O Cleavage of Strained Cycloketone Oximes

Organic Letters, Год журнала: 2019, Номер 21(8), С. 2658 - 2662

Опубликована: Апрель 3, 2019

A photoinduced, phosphoranyl radical-mediated protocol for the direct N–O cleavage of strained cycloketone oximes via a polar/SET crossover process was developed first time. This visible-light-driven activation mode oxime offers beneficial features such as streamlined synthetic and versatile photochemical reactivities. Consequently, alkenes α-trifluoromethyl with varied electronic structural acted competent radical receptors in this protocol, enabling facile accesses to range elongated cyano and/or gem-difluoroalkene-bearing compounds.

Язык: Английский

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