Cooperative NHC/Photoredox Catalysis: Three Component Radical Coupling of Aroyl Fluorides, Styrenes and Alcohols DOI

Nadine Döben,

Jannik Reimler,

Armido Studer

et al.

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(19), P. 3348 - 3353

Published: July 23, 2022

Abstract Cooperative NHC/photoredox catalysis has emerged as an important research field in recent years. Herein, the use of tertiary alcohols alkyl radical precursors to perform three component coupling with styrenes and aroyl fluorides for preparation α‐arylated aryl ketones is described. Reaction fluoride NHC catalyst provides acyl azolium ion that can be reduced by photoredox corresponding ketyl anion. Oxidatively generated C‐radicals derived from alcohol add styrene derivative subsequent cross adduct delivers after fragmentation targeted ketone. magnified image

Language: Английский

Radical NHC Catalysis DOI
Kun Liu, Max Schwenzer, Armido Studer

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(19), P. 11984 - 11999

Published: Sept. 19, 2022

Radical/radical cross-coupling reactions represent an efficient and straightforward approach for the construction of chemical bonds accordingly have drawn increasing attention over past decades. In order to achieve synthetically useful transformations, a persistent radical should be coupled with transient in accordance effect (PRE). However, known radicals outnumber by far types free radicals, which limits widespread application PRE, until today. Thus, development between has been focus, meanwhile transition-metal catalysis successfully implemented artificially prolong lifetimes, allowing their utilization formal radical/radical cross-couplings. Complementary research field recently uncovered that organocatalytically generated NHC-derived ketyl are type catalytically radicals. NHC-catalyzed transformations aldehydes carboxylic acid derivatives enabled disclosure ever-increasing number interesting reactions, different from traditional ionic processes, offering otherwise inaccessible activation modes. These discoveries opened door NHC organocatalysis manipulation reactions. Due its obvious potential synthetic organic chemistry, it is timely provide perspective on this emerging field.

Language: Английский

Citations

203
Free Carboxylic Acids: The Trend of Radical Decarboxylative Functionalization DOI
Liubo Li, Yan Yao, Niankai Fu

et al.

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(21)

Published: April 7, 2023

Abstract The exceptional versatility of carboxylic acids has been extensively exploited in organic synthesis across several decades. There a recent upsurge radical decarboxylative transformations. process can be initiated under mild conditions, and the resultant radicals have orthogonal reactivities to closed‐shell species, thus providing immense opportunities for streamlining novel reactions. use free is most desirable owing its high atom step economy. Aiming demonstrate attractiveness strategy inspire chemists tackle existing challenges, this review outlines advances on functionalization acids.

Language: Английский

Citations

54
Photoinduced Acylations Via Azolium-Promoted Intermolecular Hydrogen Atom Transfer DOI
Joshua L. Zhu,

Cullen R. Schull,

Anthony T. Tam

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(3), P. 1535 - 1541

Published: Jan. 10, 2023

Photoinduced hydrogen atom transfer (HAT) has been developed as a powerful tool to generate synthetically valuable radical species. The direct photoexcitation of ketones known promote HAT or acyl radicals through Norrish-type pathways, but these modalities remain severely limited by side reactions. We report herein catalyst- and transition metal-free method for the acylation C-H bonds that leverages unique properties stable, isolable azolium Specifically, salts are shown undergo an intermolecular regioselective upon LED irradiation with range substrates bearing active followed C-C bond formation afford ketones. Experimental computational studies support facile intersystem crossing access triplet diradical species selective radical-radical cross-coupling.

Language: Английский

Citations

52
Recent advances in combining photo- and N-heterocyclic carbene catalysis DOI Creative Commons
Xiaochen Wang,

Senhui Wu,

Rongxin Yang

et al.

Chemical Science, Journal Year: 2023, Volume and Issue: 14(46), P. 13367 - 13383

Published: Jan. 1, 2023

This review summarizes recent advances in combining photo- and N-heterocyclic carbene catalysis, as well provides an outlook on future opportunities challenges.

Language: Английский

Citations

43
Radical Reactions with N-Heterocyclic Carbene (NHC)-Derived Acyl Azoliums for Access to Multifunctionalized Ketones DOI

Hui Cai,

Xiaoqun Yang,

Shi‐Chao Ren

et al.

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

Citations

23
Photoredox cooperative N-heterocyclic carbene/palladium-catalysed alkylacylation of alkenes DOI Creative Commons

You-Feng Han,

Ying Huang, Hao Liu

et al.

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Sept. 30, 2022

Three-component carboacylation of simple alkenes with readily available reagents is challenging. Transition metal-catalysed intermolecular works for strained ring or directing groups. Herein, we develop a photoredox cooperative N-heterocyclic carbene/Pd-catalysed alkylacylation aldehydes and unactivated alkyl halides to provide ketones in good yields. This multicomponent coupling reaction features wide scope alkenes, broad functional group compatibility free exogenous photosensitizer external reductant. In addition, series chlorinated cyclopropanes one two vicinal quaternary carbons obtained when chloroform carbon tetrachloride used as the halide. The involves radicals from ketyl under carbene/Pd catalysis.

Language: Английский

Citations

60
Visible light-mediated NHCs and photoredox co-catalyzed radical 1,2-dicarbonylation of alkenes for 1,4-diketones DOI
Lihong V. Wang, Jiaqiong Sun,

Jiuli Xia

et al.

Science China Chemistry, Journal Year: 2022, Volume and Issue: 65(10), P. 1938 - 1944

Published: Sept. 2, 2022

Language: Английский

Citations

41
Direct allylic acylation via cross-coupling involving cooperative N‑heterocyclic carbene, hydrogen atom transfer, and photoredox catalysis DOI Creative Commons
Xiaochen Wang,

Rongxin Yang,

Binbing Zhu

et al.

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

Citations

33
Photoinduced Electron Transfer from Xanthates to Acyl Azoliums: Divergent Ketone Synthesis via N‐Heterocyclic Carbene Catalysis DOI
Chang‐Yin Tan, Minseok Kim, Sungwoo Hong

et al.

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

Citations

33
Recent advances in three-component radical acylative difunctionalization of unsaturated carbon–carbon bonds DOI
Jiaqiong Sun, Lihong V. Wang, Guangfan Zheng

et al.

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

Citations

31