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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Late‐Stage Functionalisation of Pyridine‐Containing Bioactive Molecules: Recent Strategies and Perspectives

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(16)

Published: Feb. 21, 2023

Abstract Late‐Stage Functionalisation (LSF) is an innovative technique that has been successfully applied to the C−H diversification of pharmaceuticals. However, LSF pyridine ring in drug‐like molecules often unselective. As a result, mixture structurally related products obtained, thus making purification tedious and time‐consuming. This review shines light on recent strategies addressing selectivity issue complex natural or drugs containing moiety. Specifically, we have reviewed efforts reported both academia industries with hope providing guide for elaborated pyridines.

Language: Английский

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Unlocking the Potential of β-Fragmentation of Aminophosphoranyl Radicals for Sulfonyl Radical Reactions

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(26), P. 14510 - 14518

Published: June 20, 2023

Exploiting β-scission in aminophosphoranyl radicals for radical-mediated transformations has been a longstanding challenge. In this study, we investigated the untapped potential of β-fragmentation by leveraging unique properties P-N bond and substituents P(III) reagents. Our approach carefully considers factors such as cone angle electronic phosphine employs density functional theory (DFT) calculations to probe structural molecular orbital influence. We successfully induced through N-S cleavage under visible light mild conditions, generating range sulfonyl derived from pyridinium salts via photochemical activity electron donor-acceptor (EDA) complexes. This innovative synthetic strategy exhibits broad applicability, including late-stage functionalization, paves way valuable reactions, alkene hydrosulfonylation, difunctionalization, pyridylic C-H sulfonylation.

Language: Английский

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Formation of C–B, C–C, and C–X Bonds from Nonstabilized Aryl Radicals Generated from Diaryl Boryl Radicals

ACS Central Science, Journal Year: 2023, Volume and Issue: 9(12), P. 2268 - 2276

Published: Nov. 13, 2023

With the development of organoboron chemistry, boron-centered radicals have become increasingly attractive. However, their synthetic applications remain limited in that they been used only as substrates for addition reactions or initiators catalytic reactions. We achieved a new reaction pathway which tetraarylborate salts are precursors aryl via boron radicals, by introducing simple activation reagent. In addition, we carried out diverse array transformations involving these radical precursors, allowed construction C–B, C–C, and C–X bonds presence visible light.

Language: Английский

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Selective multifunctionalization ofN-heterocyclic carbene boranesviathe intermediacy of boron-centered radicals

Chemical Science, Journal Year: 2023, Volume and Issue: 14(23), P. 6341 - 6347

Published: Jan. 1, 2023

The selective difunctionalization of N-heterocyclic carbene (NHC) boranes with alkenes has been achieved via decatungstate and thiol synergistic catalysis. catalytic system also allows stepwise trifunctionalization, leading to complex NHC three different functional groups which are challenging prepare by other methods. strong hydrogen-abstracting ability the excited enables generation boryl radicals from mono- di-substituted for realizing borane multifunctionalization. This proof-of-principle research provides a new chance fabricating unsymmetrical developing boron-atom-economic synthesis.

Language: Английский

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Visible-Light-Induced Alkoxypyridylation of Alkenes Using N-Alkoxypyridinium Salts as Bifunctional Reagents

Organic Letters, Journal Year: 2024, Volume and Issue: 26(17), P. 3661 - 3666

Published: April 24, 2024

Considering the ubiquitous presence of pyridine moieties in pharmaceutical compounds, it holds immense value to develop practical and straightforward methodologies for accessing heterocyclic aromatic hydrocarbons. In recent years, N-alkoxypyridinium salts have emerged as convenient radical precursors, enabling generation corresponding alkoxy radicals through single-electron transfer. Herein, we present first report on visible-light-mediated intermolecular alkoxypyridylation alkenes employing N-alkoxylpyridinium bifunctional reagents with an exceptionally low catalyst loading (0.5 mol %).

Language: Английский

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Ligand-Controlled Regioselective Dearomative Vicinal and Conjugate Hydroboration of Quinolines

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 27, 2025

A dearomative strategy to regioselectively modify arenes using a "diene" synthon within aromatic rings provides access highly functionalized heterocycles from abundant feedstocks and represents an alternative synthetic approach besides traditional cross-coupling C-H functionalization methodologies. In this study, we present efficient method for selectively introducing boron onto quinolines through hydroboration easily accessible stable phosphine-ligated borane complexes. The vicinal 5,6- conjugate 5,8-hydroborated products could be obtained by modifying the phosphine ligand. Drawing inspiration diverse organoboron transformations, these building blocks were diversified range of downstream functionalizations, providing modular pathways skeletal modifications variety challenging heterocycles.

Language: Английский

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Visible-Light-Driven Tandem Cyclization of o-Hydroxyaryl Enaminones: Access to 3-(α-Arylsulfonamido)trifluoroethyl Chromones

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 22, 2025

A visible-light-driven intermolecular tandem α-amidotrifluoroethylation/cyclization of enaminones using a previously unreported N-trifluoroethylaminopyridinium salt was achieved in the absence transition metal catalysts or bases. Notable features this synthetic method include mild conditions, high selectivity, excellent functional group compatibility, and satisfactory yields. Preliminary mechanistic studies indicate that reaction proceeds via radical pathway, involving an situ generated N-trifluoroethyl radical, followed by 1,2-H shift.

Language: Английский

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Transition Metal‐Free Aromatic C−H, C−N, C−S and C−O Borylation

The Chemical Record, Journal Year: 2023, Volume and Issue: 23(4)

Published: Feb. 27, 2023

Abstract Aromatic organoboron compounds are highly valuable building blocks in organic chemistry. They were mainly synthesized through aromatic C−H and C−Het borylation, which transition metal‐catalysis dominate. In the past decade, with increasing attention to sustainable chemistry, numerous metal‐free borylation transformations have been developed emerged as efficient methods towards synthesis of compounds. This account focuses on recent advances C−H, C−N, C−S, C−O provides insights where further developments required.

Language: Английский

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DBU‐Promoted [3 + 2] Cyclization/Retro‐Mannich Cascade Reaction of N‐Aminoisoquinolinium and N‐Aminoquinolinium Derivatives with para‐Quinone Methides

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(9), P. 2003 - 2007

Published: March 12, 2024

Abstract A DBU‐promoted [3+2] cyclization/retro‐Mannich cascade reaction of N ‐aminoisoquinolinium and ‐aminoquinolinium derivatives with para ‐quinone methides has been established, employing a C=C double bond cleavage. broad range salts, are well tolerated, providing the corresponding rearrangement products. Moreover, scaled‐up reactions diverse derivatizations products were also investigated discussed.

Language: Английский

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