Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

ACS Catalysis, Год журнала: 2021, Номер 11(3), С. 1640 - 1683

Опубликована: Янв. 20, 2021

The past decade has witnessed the emergence of N-(acyloxy)phthalimides (NHPI esters) and its derivatives at forefront synthetic methods facilitating construction diverse molecular frameworks from readily available carboxylic acid feedstock. NHPI esters are predisposed to undergo reductive fragmentation via a single electron transfer (SET) process under thermal, photochemical, or electrochemical conditions generate corresponding carbon- nitrogen-centered radicals that participate in multitude transformations forge carbon–carbon carbon–heteroatom bonds. chemistry involving received broad applicability not only well-designed cascade annulations but also medicinal natural product synthesis. This comprehensive Review, broadly categorized according nature bond formation, details progress made this field since initial discovery by providing representative examples with mechanistic details, an emphasis on challenges future directions.

Язык: Английский

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Recent progress in cathodic reduction-enabled organic electrosynthesis: Trends, challenges, and opportunities

eScience, Год журнала: 2022, Номер 2(3), С. 243 - 277

Опубликована: Апрель 23, 2022

Compared with general redox chemistry, electrochemistry using the electron as a potent, controllable, yet traceless alternative to chemical oxidants/reductants usually offers more sustainable options for achieving selective organic synthesis. With its environmentally benign features gradually being uncovered and studied, electrosynthesis is currently undergoing revival becoming rapidly growing area within synthetic community. Among electrochemical transformations, anodically enabled ones have been far extensively exploited than those driven by cathodic reduction, although both approaches are conceptually attractive. To stimulate development of cathodically reactions, this review summarizes recently developed reductive electrosynthetic protocols, discussing highlighting reaction features, substrate scopes, applications, plausible mechanisms reveal recent trends in area. Herein, reduction-enabled preparative transformations categorized into four types: reduction (1) unsaturated hydrocarbons, (2) heteroatom-containing carbon-based systems, (3) saturated C-hetero or C–C polar/strained bonds, (4) hetero-hetero linkages. Apart from net electroreductive few examples photo-electrosynthesis well paired electrolysis also introduced, which offer opportunities overcome certain limitations improve versatility. The electrochemically driven, transition metal-catalyzed cross-couplings that comprehensively discussed several other reviews not included here.

Язык: Английский

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Photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones

CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION), Год журнала: 2021, Номер 42(11), С. 1921 - 1943

Опубликована: Авг. 30, 2021

Язык: Английский

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Carbon dioxide cycle via electrocatalysis: Electrochemical carboxylation of CO2 and decarboxylative functionalization of carboxylic acids

Green Synthesis and Catalysis, Год журнала: 2021, Номер 2(1), С. 19 - 26

Опубликована: Фев. 1, 2021

As one of the most important biogeochemical cycles, carbon dioxide (CO2) cycle between atmosphere and biosphere has a profound impact on life earth. Therefore, search for sustainable solutions to normalize currently unbalanced is central research topic many scientific disciplines. The green electrocatalysis offers very promising answer cycle. In this review, recent advances in enabled CO2 including electrochemical carboxylation decarboxylative functionalization carboxylic acids are highlighted.

Язык: Английский

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Electrochemical Nozaki–Hiyama–Kishi Coupling: Scope, Applications, and Mechanism

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(25), С. 9478 - 9488

Опубликована: Июнь 15, 2021

One of the most oft-employed methods for C–C bond formation involving coupling vinyl-halides with aldehydes catalyzed by Ni and Cr (Nozaki–Hiyama–Kishi, NHK) has been rendered more practical using an electroreductive manifold. Although early studies pointed to feasibility such a process, those precedents were never applied others due cumbersome setups limited scope. Here we show that carefully optimized procedure can enable sustainable approach NHK, even in asymmetric fashion on highly complex medicinally relevant systems. The e-NHK non-canonical substrate classes, as redox-active esters, participate low loadings when conventional chemical techniques fail. A combination detailed kinetics, cyclic voltammetry, situ UV–vis spectroelectrochemistry these processes illuminates subtle features this mechanistically intricate process.

Язык: Английский

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Organophotoelectrocatalytic C(sp²)–H alkylation of heteroarenes with unactivated C(sp³)–H compounds

Chemical Communications, Год журнала: 2024, Номер 60(42), С. 5502 - 5505

Опубликована: Янв. 1, 2024

An organophotoelectrocatalytic method for the C(sp 2 )–H alkylation of heteroarenes with unactivated 3 compounds via dehydrogenation cross-coupling was developed.

Язык: Английский

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Practical and Regioselective Synthesis of C-4-Alkylated Pyridines

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(31), С. 11927 - 11933

Опубликована: Июль 28, 2021

The direct position-selective C-4 alkylation of pyridines has been a long-standing challenge in heterocyclic chemistry, particularly from pyridine itself. Historically this addressed using prefunctionalized materials to avoid overalkylation and mixtures regioisomers. This study reports the invention simple maleate-derived blocking group for that enables exquisite control Minisci-type decarboxylative at allows inexpensive access these valuable building blocks. method is employed on variety different carboxylic acid alkyl donors, operationally scalable, applied known structures rapid fashion. Finally, work points an interesting strategic departure use Minisci chemistry earliest possible stage (native pyridine) rather than current dogma almost exclusively employs as late-stage functionalization technique.

Язык: Английский

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Metal-Free Photosynthesis of Alkylated Benzimidazo[2,1-a]isoquinoline-6(5H)-ones and Indolo[2,1-a]isoquinolin-6(5H)-ones in PEG-200

The Journal of Organic Chemistry, Год журнала: 2021, Номер 86(13), С. 9055 - 9066

Опубликована: Июнь 23, 2021

A visible-light-induced decarboxylation reaction was developed for the synthesis of alkylated benzimidazo[2,1-a]isoquinoline-6(5H)-ones and indolo[2,1-a]isoquinolin-6(5H)-ones under metal-free conditions. Impressively, metal catalysts traditionally volatile organic solvents could be effectively avoided.

Язык: Английский

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Photoinduced Three-Component Difluoroalkylation of Quinoxalinones with Alkenes via Difluoroiodane(III) Reagents

Organic Letters, Год журнала: 2022, Номер 24(19), С. 3576 - 3581

Опубликована: Май 12, 2022

An environmentally friendly strategy for the photocatalyzed three-component reaction between quinoxalinones, alkenes, and hypervalent iodine(III) reagents is disclosed. The new designed difluoroiodane(III) reagent shows excellent reactivity, providing a wide range of difluoroalkyl-substituted quinoxaline-2(1H)-ones in moderate to yields under mild conditions. Experimental studies demonstrated that difluoroalkyl radical intermediate was involved this reaction.

Язык: Английский

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Photosynthesis of 3-Alkylated Coumarins from Carboxylic Acids Catalyzed by a Na₂S-Based Electron Donor–Acceptor Complex

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(4), С. 2288 - 2295

Опубликована: Фев. 4, 2023

A simple and practical electron donor-acceptor (EDA) strategy to synthesize various 3-alkylated coumarins from easily available naturally abundant carboxylic acids under photocatalyst-, oxidant-, additive-free mild conditions is reported. Using Na2S as the catalytic donor, a series of primary, secondary, tertiary carbon radicals can be efficiently generated, EDA complex regenerated without an alkaline additive.

Язык: Английский

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