Stereoselective construction of atropisomers featuring a C–N chiral axis

Green Synthesis and Catalysis, Год журнала: 2022, Номер 3(2), С. 117 - 136

Опубликована: Янв. 4, 2022

Atropisomeric C–N compounds belong to an important class of axially chiral compounds. However, whereas the asymmetric synthesis biaryl atropisomers have been well established, general and efficient strategies access single enantiomers are still rare. Until recently, innovative methods developed, providing new opportunities for highly stereoselective this vital atropisomers. Herein, we comprehensively summarize development in emerging field give some insights into future advance. Emphasis is placed on synthetic strategies.

Язык: Английский

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Electroreduction Enables Regioselective 1,2‐Diarylation of Alkenes with Two Electrophiles

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(17)

Опубликована: Фев. 24, 2023

Precisely introducing two similar functional groups into bulk chemical alkenes represents a formidable route to complex molecules. Especially, the selective activation of electrophiles is in crucial demand, yet challenging for cross-electrophile-coupling. Herein, we demonstrate redox-mediated electrolysis, which aryl nitriles are both radical precursors and redox-mediators, enables an intermolecular alkene 1,2-diarylation with remarkable regioselectivity, thereby avoiding involvement transition-metal catalysts. This transformation utilizes cyanoarene anions activating various halides (including iodides, bromides, even chlorides) affords adducts up 83 % yield >20 : 1 regioselectivity more than 80 examples, providing feasible approach bibenzyl derivatives.

Язык: Английский

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Paired Electrolysis-Enabled Arylation of Quinoxalin-2(1H)-ones

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(9), С. 6117 - 6125

Опубликована: Апрель 24, 2024

The first paired electrolysis-enabled arylation of quinoxalin-2(1H)-ones was achieved using cyanoarenes as the reagents. A variety 3-arylquinoxalin-2(1H)-ones with various important functional groups were obtained in moderate to good yields under metal- and chemical oxidant-free conditions. With a pair reductive oxidative processes occurring among substrates reaction intermediates, power consumption can be dramatically reduced.

Язык: Английский

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Selective Coupling of 1,2‐Bis‐Boronic Esters at the more Substituted Site through Visible‐Light Activation of Electron Donor–Acceptor Complexes

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(18)

Опубликована: Фев. 25, 2022

1,2-Bis-boronic esters are useful synthetic intermediates particularly as the two boronic can be selectively functionalized. Usually, less hindered primary ester reacts, but herein, we report a coupling reaction that enables reversal of this selectivity. This is achieved through formation boronate complex with an electron-rich aryllithium which, in presence electron-deficient aryl nitrile, leads to electron donor-acceptor complex. Following visible-light photoinduced transfer, radical generated which isomerizes more stable secondary before radical-radical arene radical-anion, giving β-aryl products. The reactions proceed under catalyst-free conditions. method also allows stereodivergent cyclic cis-1,2-bis-boronic provide trans-substituted products, complementing selectivity observed Suzuki-Miyaura reaction.

Язык: Английский

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Divergent C(sp²)–H arylation of heterocycles via organic photoredox catalysis

Green Chemistry, Год журнала: 2022, Номер 24(7), С. 3017 - 3022

Опубликована: Янв. 1, 2022

Introducing aryl moieties into heterocyclic scaffolds is a key step in the syntheses of natural products, drugs, and functional materials.

Язык: Английский

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Light-Driven Cobalt Hydride Catalyzed Hydroarylation of Styrenes

ACS Catalysis, Год журнала: 2022, Номер 12(24), С. 14806 - 14811

Опубликована: Ноя. 22, 2022

We report a conceptually distinct strategy for the synthesis of 1,1-diarylalkanes and triarylalkanes. Key to this approach is use light simultaneously trigger (i) formation CoIII–H species which undergoes H atom transfer (MHAT) styrenes, giving carbon-centered radical, (ii) generation persistent (hetero)arene radical. Selective coupling these two yields Markovnikov hydroarylation products under mild conditions without precious metals. In contrast many previous approaches, electron-deficient partners are favored it possible construct highly congested quaternary centers, including those with three different aryl groups.

Язык: Английский

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Photochemical Organocatalytic Functionalization of Pyridines via Pyridinyl Radicals

Journal of the American Chemical Society, Год журнала: 2022, Номер 145(1), С. 47 - 52

Опубликована: Дек. 27, 2022

We report a photochemical method for the functionalization of pyridines with radicals derived from allylic C–H bonds. Overall, two substrates undergo to form new C(sp2)–C(sp3) bond. The chemistry harnesses unique reactivity pyridinyl radicals, generated upon single-electron reduction pyridinium ions, which effective coupling radicals. This novel mechanism enables distinct positional selectivity pyridine that diverges classical Minisci chemistry. Crucial was identification dithiophosphoric acid masters three catalytic tasks, sequentially acting as Brønsted protonation, single electron transfer (SET) reductant ion reduction, and hydrogen atom abstractor activation C(sp3)–H resulting then couple high regioselectivity.

Язык: Английский

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Electrophotocatalytic Reductive 1,2‐Diarylationof Alkenes with Aryl Halides and Cyanoaromatics

Chinese Journal of Chemistry, Год журнала: 2023, Номер 41(16), С. 1921 - 1930

Опубликована: Апрель 7, 2023

Comprehensive Summary The radical‐mediated reductive functionalization of aryl halides has been extensively studied. However, the related intermolecular 1,2‐diarylation alkenes, using as radical sources, remains unexplored. Herein, a new electrophotocatalytic alkenes is reported and cyanoaromatics to produce polyarylated alkanes. Using synergistic cathodic reduction visible‐light photoredox catalysis, various electron‐rich electron‐deficient are combined with characterize broad substrate scope, excellent functional group compatibility, selectivity this reaction. Mechanistic investigations reveal that reaction may proceed via process initiated by generation radicals from terminated radical‐radical coupling cyanoaromatic anions.

Язык: Английский

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Asymmetric [3 + 2] Photocycloaddition of β-Keto Esters and Vinyl Azides by Dual Photoredox/Nickel Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(22), С. 12233 - 12243

Опубликована: Май 24, 2023

Photocatalytic [3 + 2] cycloadditions and control of stereochemistry have remained a substantial challenge, particularly in the context heterocycle synthesis; sporadic successful examples involved enantioselective photocycloaddition between redox-active direct group-containing cyclopropanes alkenes for creation cyclopentanes. Herein, we report cooperative catalytic system comprising chiral nickel Lewis acid catalyst an organic photocatalyst fueled by visible-light irradiation that allows hitherto elusive asymmetric β-keto esters with vinyl azides under redox-neutral conditions. This protocol enables highly construction polycyclic densely substituted 3,4-dihydro-2H-pyrrole heterocycles featuring two contiguous tetrasubstituted carbon stereocenters, including useful N,O-ketal motif is not easily accessible other methods. Mechanistic studies revealed overall reactivity relies on seamless integration dual roles catalysts formation substrate/Ni complex, assisting both photoredox event radical addition.

Язык: Английский

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Electrochemical multicomponent [2+2+1] cascade cyclization of enaminones and primary amines towards the synthesis of 4-acylimidazoles

Chemical Communications, Год журнала: 2024, Номер 60(19), С. 2677 - 2680

Опубликована: Янв. 1, 2024

An electrochemical multicomponent [2+2+1] cascade cyclization of enaminones and primary amines towards the synthesis 4-acylimidazoles has been developed. In an undivided cell, can smoothly participate in this reaction to provide a series 1,2-disubstituted at room temperature. The avoids use both transition-metal catalysts oxidation reagents, which makes it more sustainable renewable.

Язык: Английский

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