Late-stage C–H functionalization offers new opportunities in drug discovery

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(8), P. 522 - 545

Published: July 13, 2021

Language: Английский

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Visible‐Light‐Induced 1,3‐Aminopyridylation of [1.1.1]Propellane with N‐Aminopyridinium Salts

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(14), P. 7873 - 7879

Published: Jan. 7, 2021

Through the formation of an electron donor-acceptor (EDA) complex, strain-release aminopyridylation [1.1.1]propellane with N-aminopyridinium salts as bifunctional reagents enabled direct installation amino and pyridyl groups onto bicyclo[1.1.1]pentane (BCP) frameworks in absence external photocatalyst. The robustness this method to synthesize 1,3-aminopyridylated BCPs under mild metal-free conditions is highlighted by late-stage modification structurally complex biorelevant molecules. Moreover, strategy was extended P-centered CF3 radicals for unprecedented incorporation such functional pyridine across BCP core a three-component coupling. This practical lays foundation straightforward construction new valuable C4-pyridine-functionalized chemical entities, thus significantly expanding range accessibility BCP-type bioisosteres applications drug discovery.

Language: Английский

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Site-Selective Direct C–H Pyridylation of Unactivated Alkanes by Triplet Excited Anthraquinone

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(7), P. 3003 - 3012

Published: Feb. 8, 2021

Site-selective C-H functionalization in chemical feedstocks is a challenging and useful reaction the broad field of research. Here, we report modular photochemical platform for site-selective pyridylation unactivated hydrocarbons via unique synergistic effects triplet excited anthraquinone an amidyl radical-based reverse hydrogen atom transfer (RHAT) agent. The selective tertiary secondary C(sp3)-H bonds abundant was achieved by employing various N-aminopyridinium salts highly fashion, thus providing new catalytic system direct construction high-value-added compounds under ambient conditions. Moreover, this operationally simple protocol applicable to variety linear-, branched-, cyclo-alkanes more complex molecules with high degrees site selectivity visible-light conditions, which provides rapid straightforward access versatile synthons upgrading mild, metal-free

Language: Английский

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Recent advances in radical chemistry proceeding through pro-aromatic radicals

Chem, Journal Year: 2021, Volume and Issue: 7(8), P. 2060 - 2100

Published: April 21, 2021

Language: Английский

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Late-Stage C–H Functionalization of Azines

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(12), P. 7655 - 7691

Published: May 3, 2023

Azines, such as pyridines, quinolines, pyrimidines, and pyridazines, are widespread components of pharmaceuticals. Their occurrence derives from a suite physiochemical properties that match key criteria in drug design is tunable by varying their substituents. Developments synthetic chemistry, therefore, directly impact these efforts, methods can install various groups azine C–H bonds particularly valuable. Furthermore, there growing interest late-stage functionalization (LSF) reactions focus on advanced candidate compounds often complex structures with multiple heterocycles, functional groups, reactive sites. Because factors electron-deficient nature the effects Lewis basic N atom, distinct arene counterparts, application LSF contexts difficult. However, have been many significant advances reactions, this review will describe progress, much which has occurred over past decade. It possible to categorize radical addition processes, metal-catalyzed activation transformations occurring via dearomatized intermediates. Substantial variation reaction within each category indicates both rich reactivity heterocycles creativity approaches involved.

Language: Английский

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N-Functionalized Pyridinium Salts: A New Chapter for Site-Selective Pyridine C–H Functionalization via Radical-Based Processes under Visible Light Irradiation

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(20), P. 3043 - 3056

Published: Sept. 27, 2022

ConspectusThe radical-mediated C–H functionalization of pyridines has attracted considerable attention as a powerful tool in synthetic chemistry for the direct bonds pyridine scaffold. Classically, methods functionalized often involve Minisci-type reactions under strongly acidic conditions. However, site-selective unbiased systems been long-standing challenge because scaffold contains multiple competing reaction sites (C2 vs C4) to intercept free radicals. Therefore, prefunctionalization is required avoid issues observed with formation mixture regioisomers and overalkylated side products.Recently, N-functionalized pyridinium salts have attracting organic promising radical precursors surrogates. The notable advantage lies their ability enhance reactivity selectivity synthetically useful acid-free This approach enables exquisite regiocontrol nonclassical at C2 C4 positions mild conditions, which are suitable late-stage bioactive molecules greater complexity diversity. Over past five years, variety fascinating applications developed using various types visible light In addition, new platform alkene difunctionalization appropriately designed N-substituted bifunctional reagents reported, offering an innovative assembly process complex architectures. Intriguingly, strategies involving light-absorbing electron donor–acceptor (EDA) complexes between electron-rich donors further open up photocatalyst-free Furthermore, we enantioselective afford enantioenriched bearing through single-electron N-heterocyclic carbene (NHC) catalysis.Herein, provide broad overview our recent contributions development summarize cornerstones that successfully employ these major advances field systematically categorized on basis pyridines' N-substituent, N–X (X = O, N, C, SO2CF3), its patterns. identification activation modes mechanistic aspects discussed by providing representative each paradigm. We hope this Account will inspire interest continued innovation exploration transformations.

Language: Английский

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Sulfonium Salts as Acceptors in Electron Donor‐Acceptor Complexes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(29)

Published: March 24, 2023

Abstract The photoactivation of electron donor‐acceptor complexes has emerged as a sustainable, selective and versatile strategy for the generation radical species. Electron (EDA) complexation, however, imposes electronic constraints on donor acceptor components this can limit range radicals that be generated using approach. New EDA complexation strategies exploiting sulfonium salts allow to from native functionality. For example, aryl salts, formed by activation arenes, serve in due their electron‐deficient nature. This “sulfonium tag” approach relaxes parent substrate dramatically expands complexation. In review, these new applications will introduced areas chemical space rendered accessible through innovation highlighted.

Language: Английский

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Recent Advances in Electron Donor‐Acceptor (EDA)‐Complex Reactions involving Quaternary Pyridinium Derivatives

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(10), P. 1538 - 1564

Published: March 6, 2023

Abstract Quaternary pyridinium compounds are valuable intermediates in organic synthesis, which have gained immense popularity the synthetic community. The application of transition metal or photoredox catalysis transforming quaternary into various C−C and C−X bonds is well established. A majority these methods require high temperatures, expansive catalysts, delicate conditions for successful execution. On other hand, use metal‐free photocatalysis‐free strategies constructing using derivatives has been sought‐after. In this context, electron‐donor‐acceptor (EDA)‐complex reactions emerged as a state‐of‐the‐art methodology, do not any photocatalyst their EDA‐complex photochemistry takes advantage electron‐acceptor ability derivatives, can quickly generate radical precursor via deaminative process. These newly generated useful several transformations. We hereby, review, discuss an area major progress mediated involving with mechanism, substrate scope, limitations. magnified image

Language: Английский

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Transformations of carbohydrate derivatives enabled by photocatalysis and visible light photochemistry

Chemical Science, Journal Year: 2024, Volume and Issue: 15(4), P. 1204 - 1236

Published: Jan. 1, 2024

This review article highlights the diverse ways in which recent developments areas of photocatalysis and visible light photochemistry are impacting synthetic carbohydrate chemistry.

Language: Английский

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Practical and Regioselective Synthesis of C-4-Alkylated Pyridines

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(31), P. 11927 - 11933

Published: July 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.

Language: Английский

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