Radical Reactions with N-Heterocyclic Carbene (NHC)-Derived Acyl Azoliums for Access to Multifunctionalized Ketones

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(11), P. 8270 - 8293

Published: May 13, 2024

As one of the most important key intermediates, NHC-bound acylazolium-based ionic transformations have been intensively explored in past two decades. With expeditious development NHC-catalyzed radical recent years, acylazolium chemistry has reached another level, with number relevant publications increasing significantly. However, a summary focused on acylations NHC-derived acyl azoliums classified according to mechanistic difference not reported. Such detailed classification and deep analysis provide opportunities for better understanding history trend this field. In review, reactions N-heterocyclic carbene (NHC)-derived are systematically introduced. The achievements challenges within area also summarized discussed at end.

Language: Английский

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Branched-Selective Hydroacylation of Alkenes via Photoredox Cobalt and N-Heterocyclic Carbene Cooperative Triple Catalysis

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 15241 - 15248

Published: Nov. 29, 2022

A Markovnikov-selective hydroacylation of alkenes has been achieved via the synergistic merger cobalt, photoredox and N-heterocyclic carbene catalysis. The closely incorporated catalytic cycles allow for Co(III) generation by photochemical oxidation instead chemical oxidants or anodizing process. This mild, operationally simple protocol converts a wide variety commercially available aroyl fluorides into corresponding ketones in high yield with branched selectivity.

Language: Английский

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Direct allylic acylation via cross-coupling involving cooperative N‑heterocyclic carbene, hydrogen atom transfer, and photoredox catalysis

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: May 23, 2023

Herein, we report a mild, operationally simple, multicatalytic method for the synthesis of β,γ-unsaturated ketones via allylic acylation alkenes. Specifically, combines N‑heterocyclic carbene catalysis, hydrogen atom transfer and photoredox catalysis cross-coupling reactions between wide range feedstock carboxylic acids readily available olefins to afford structurally diverse without olefin transposition. The could be used install acyl groups on highly functionalized natural-product-derived compounds with no need substrate pre-activation, C-H functionalization proceed excellent site selectivity. To demonstrate potential applications method, convert representative coupling product into various useful synthons.

Language: Английский

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Photoinduced Electron Transfer from Xanthates to Acyl Azoliums: Divergent Ketone Synthesis via N‐Heterocyclic Carbene Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(32)

Published: June 12, 2023

Considering the prevalence of alcohols and carboxylic acids, their fragment cross-coupling reactions could hold significant implications in organic synthesis. Herein, we report a versatile method for synthesizing diverse range ketones from acid derivatives via N-heterocyclic carbene (NHC) catalysis. Mechanistic investigations revealed that photoexcited xanthates acyl azoliums undergo single electron transfer (SET) under photocatalyst-free conditions, generating NHC-derived ketyl radicals alkyl radicals. These open-shell intermediates subsequently radical-radical reaction, yielding valuable ketones. Furthermore, this approach can be employed three-component involving alkenes enynes, resulting structurally cross-coupled The unified strategy offers unique opportunity coupling derivatives, accommodating functional groups even complex settings.

Language: Английский

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Iminoacylation of Alkenes via Photoredox N-Heterocyclic Carbene Catalysis

Organic Letters, Journal Year: 2023, Volume and Issue: 25(5), P. 855 - 860

Published: Jan. 26, 2023

The iminoacylation of alkenes via photoredox N-heterocyclic carbene catalysis is developed with the employment alkene-tethered α-imino-oxy acids and acyl imidazoles. corresponding substituted 3,4-dihydro-2H-pyrroles were afforded in moderate to good yields high diastereoselectivities most cases. reaction involves 5-exo-trig radical cyclization an iminyl following coupling a ketyl from imidazole under NHC catalysis.

Language: Английский

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Recent advances in three-component radical acylative difunctionalization of unsaturated carbon–carbon bonds

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(18), P. 4488 - 4515

Published: Jan. 1, 2023

This review highlights the recent advances in radical acylated difunctionalization of unsaturated carbon–carbon bonds and focuses on mechanistic insights these transformations.

Language: Английский

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N-heterocyclic carbene- and organic photoredox-catalysed meta-selective acylation of electron-rich arenes

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(11), P. 1037 - 1045

Published: Aug. 3, 2023

Language: Английский

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Light‐Driven Enantioselective Carbene‐Catalyzed Radical‐Radical Coupling

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(49)

Published: Oct. 17, 2023

Abstract An enantioselective carbene‐catalyzed radical‐radical coupling of acyl imidazoles and racemi c Hantzsch esters is disclosed. This method involves the an N‐heterocyclic carbene‐derived ketyl radical a secondary sp 3 ‐carbon allows access to chiral α‐aryl aliphatic ketones in moderate‐to‐good yields enantioselectivities without any competitive epimerization. The utility this protocol highlighted by late‐stage functionalization various pharmaceutical compounds further demonstrated transformation enantioenriched products biologically relevant molecules. Computational investigations reveal carbene controls double‐facial selectivity alkyl radicals, respectively.

Language: Английский

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Mesoionic Carbene‐Catalyzed Formyl Alkylation of Aldehydes

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(24)

Published: April 18, 2023

Ketones are among the most useful functional groups in organic synthesis, and they commonly encountered a broad range of compounds with various applications. Herein, we describe mesoionic carbene-catalyzed coupling reaction aldehydes non-activated secondary even primary alkyl halides. This metal-free method utilizes deprotonated Breslow intermediates derived from carbenes (MICs), which act as super electron donors induce single-electron reduction mild has substrate scope tolerates many groups, allows to prepare diversity simple ketones well bio-active molecules by late-stage functionalization.

Language: Английский

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Visible light-induced synthesis of 1,3-disubstituted bicyclo[1.1.1]pentane ketonesviacooperative photoredox and N-heterocyclic carbene catalysis

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(10), P. 3909 - 3915

Published: Jan. 1, 2023

Visible light-induced highly efficient synthesis of 1,3-disubstituted bicyclo[1.1.1]pentane with mild conditions, high atom economy, and superior functional group tolerance.

Language: Английский

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