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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When Light Meets Nitrogen-Centered Radicals: From Reagents to Catalysts

Accounts of Chemical Research, Год журнала: 2020, Номер 53(5), С. 1066 - 1083

Опубликована: Апрель 14, 2020

ConspectusNitrogen-centered radicals (NCRs) are a versatile class of highly reactive species that have longer history than the classical carbon-based in synthetic chemistry. Depending on N-hybridization and substitution patterns, NCRs can serve as electrophiles or nucleophiles to undergo various radical transformations. Despite their power, progress nitrogen-radical chemistry is still slow compared with popularity carbon radicals, considerable potential has been largely underexplored, which is, concluded by Zard, mainly hampered "a dearth convenient access these lack awareness pertaining reactivity".Over past decade, visible-light photoredox catalysis established powerful toolbox chemists use generate diverse range intermediates from native organic functional groups via single electron transfer process energy under mild reaction conditions. This catalytic strategy typically obviates need for external stoichiometric activation reagents toxic initiators often enables traditionally inaccessible ionic chemical reactions. On basis our long-standing interest nitrogen catalysis, we emphasized tactic discover develop novel methods generating controlled fashion applications. In this Account, describe recent advances development visible-light-driven photoredox-catalyzed generation applications.Inspired natural biological proton-coupled (PCET) process, first developed oxidative deprotonation activate N–H bonds hydrazones, benzamides, sulfonamides give corresponding With species, then achieved 5-exo 6-endo cyclizations well cascade reactions regioselective manner, providing variety potentially useful heterocycles. To further expand repertoire possible NCRs, also revealed iminyl derived O-acyl cycloalkanone oxime esters, facile ring-opening C–C bond cleavage cyanoalkyl radicals. These newly formed bond-forming allow synthesis distally functionalized alkyl nitriles. Stimulated studies, wide copper-catalyzed cross-coupling Because inherent transient properties, heteroatom-centered underexplored synthesis. Building understanding fundamental time concept NCR covalent involves situ-photogenerated allyl sulfones, vinylcyclopropanes, N-tosyl vinylaziridines. thus enabled efficient difunctionalization alkenes late-stage modification complex biologically active molecules.In panoramic picture contributions since 2014 application systems field studies provide not only functionally rich molecules but some insight into exploration new reactivity modes NCRs.

Язык: Английский

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Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis

Chemical Reviews, Год журнала: 2021, Номер 122(2), С. 2017 - 2291

Опубликована: Ноя. 23, 2021

We present here a review of the photochemical and electrochemical applications multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms which both an proton exchanged together, often concerted elementary step. As such, MS-PCET can function as non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from wide variety common functional groups. introduction practitioner’s guide reaction design, with emphasis on unique energetic selectivity features that characteristic this class. then chapters oxidative N–H, O–H, S–H, C–H homolysis methods, generation corresponding neutral species. Then, reductive PCET activations involving carbonyl, imine, other X═Y π-systems, heteroarenes, where ketyl, α-amino, heteroarene-derived radicals be generated. Finally, we asymmetric catalysis materials device applications. Within each chapter, subdivide by group undergoing homolysis, thereafter type transformation being promoted. Methods published prior end December 2020 presented.

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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Recent advances in sulfonylation reactions using potassium/sodium metabisulfite

Chemical Communications, Год журнала: 2020, Номер 56(30), С. 4145 - 4155

Опубликована: Янв. 1, 2020

Recently, sulfonylation reactions using potassium/sodium metabisulfite as the sulfur dioxide surrogate have been developed rapidly. In most cases, transformations go through radical processes with insertion of under mild conditions. Additionally, transition metal catalysis is applied in for synthesis sulfonyl-containing compounds. Among approaches, photoinduced conversions visible light or ultraviolet irradiation are also involved. this updated report, from potassium sodium summarized.

Язык: Английский

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Phosphoranyl Radical Fragmentation Reactions Driven by Photoredox Catalysis

ACS Catalysis, Год журнала: 2020, Номер 10(13), С. 7250 - 7261

Опубликована: Июнь 5, 2020

Photocatalytic generation of phosphoranyl radicals is fast emerging as an essential method for the diverse and valuable radicals, typically via deoxygenation or desulfurization processes. This Perspective a comprehensive evaluation all studies using tunable mediators in photoredox catalysis, highlighting how two distinct methods radical formation (radical addition nucleophilic addition) can be used to generate versatile intermediates with reactivity profiles.

Язык: Английский

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Photochemical radical cyclization reactions with imines, hydrazones, oximes and related compounds

Chemical Society Reviews, Год журнала: 2021, Номер 50(13), С. 7418 - 7435

Опубликована: Янв. 1, 2021

Photochemical reactions of imines, hydrazones, oximes and related compounds provides an efficient access to radical intermediates in the synthesis heterocycles.

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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Synthesis of Azabicyclo[3.1.1]heptenes Enabled by Catalyst-Controlled Annulations of Bicyclo[1.1.0]butanes with Vinyl Azides

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(27), С. 18565 - 18575

Опубликована: Июнь 27, 2024

Bridged bicyclic scaffolds are emerging bioisosteres of planar aromatic rings under the concept "escape from flatland". However, adopting this into exploration pyridines remains elusive due to challenge incorporating a N atom such bridged structures. Herein, we report practical routes for divergent synthesis 2- and 3-azabicyclo[3.1.1]heptenes (aza-BCHepes) as potential readily accessible vinyl azides bicyclo[1.1.0]butanes (BCBs) via two distinct catalytic annulations. The reactivity tailored with BCBs is key achieving transformations. Ti

Язык: Английский

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Photoinduced Copper-Catalyzed Radical Aminocarbonylation of Cycloketone Oxime Esters

ACS Catalysis, Год журнала: 2019, Номер 9(9), С. 8159 - 8164

Опубликована: Авг. 1, 2019

A visible light-induced and exogenous photosensitizer-free, copper-catalyzed radical aminocarbonylation of cycloketone oxime esters with CO gas amines is developed. The mild catalytic system involving CuCl N,N,N-tridentate ligand shows good reactivity chemoselectivity, tolerates a wide range alkyl/aryl amines, giving the corresponding cyanoalkylated amides in moderate to yields. Preliminary mechanistic studies suggest that reaction involves CuI/CuII/CuIII-based cycle intermediate.

Язык: Английский

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