Dual N-Heterocyclic Carbene/Photoredox-Catalyzed Coupling of Acyl Fluorides and Alkyl Silanes DOI Creative Commons
Michael Jakob, Luca Steiner,

Marius Göbel

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 17642 - 17653

Published: Nov. 15, 2024

The combination of N-heterocyclic carbene (NHC) organocatalysis with photochemical activation is becoming increasingly established as an approach for conducting radical organic reactions under mild and practical conditions. As comparatively easy to prepare handle compounds, alkyl silanes are attractive substrates chemistry desilylative mesolysis the corresponding cations known be rapid. Here, we report successful application benzyl silane derivatives source radicals in dual NHC/photoredox-catalyzed radical–radical coupling acyl fluorides. Relatively electron-rich reacted smoothly afford ketones generally good yields, while optimization NHC photocatalyst allowed a wider scope including primary substrates. Furthermore, initial experiments revealed that organosilanes bearing N-, O- S-heteroatoms can also serve sources these

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
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
Branched-Selective Hydroacylation of Alkenes via Photoredox Cobalt and N-Heterocyclic Carbene Cooperative Triple Catalysis DOI
Xiangzhang Tao, Qing Wang, Lingyu Kong

et al.

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

Citations

42
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
Cooperative Photoredox and N‐Heterocyclic Carbene Catalyzed Fluoroaroylation for the Synthesis of α‐Trifluoromethyl‐Substituted Ketones DOI
Xiaoye Yu,

A.C. Maity,

Armido Studer

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(48)

Published: Oct. 9, 2023

α-Trifluoromethylated ketones have attracted significant attention as valuable building blocks in organic synthesis. Such compounds are generally accessed through trifluoromethylation of ketones. Here we report an alternative disconnection approach for the construction α-CF3 carbonyl by using aroyl fluorides bifunctional reagents fluoroaroylation gem-difluoroalkenes cooperative photoredox and N-heterocyclic carbene (NHC) catalysis. This strategy bypasses use expensive or sensitive and/or requirement ketone pre-functionalization, thus enabling efficient general synthetic method to access -substituted A wide variety bearing a diverse set functional groups eligible substrates. Notably, developed methodology also provides rapid mono- difluoroalkyl Mechanistic studies reveal that merging catalysis with NHC is essential reaction.

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
Radical acylation: concepts, synthetic applications and directions DOI
Yue Zhang, Yili Zhang, Jian Lin

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(4), P. 1056 - 1085

Published: Jan. 1, 2023

In this tutorial, reaction scopes, limitations and mechanisms of radical acylations are summarized discussed according to types catalytic systems.

Language: Английский

Citations

20
Cooperative Carbene Photocatalysis for β-Amino Ester Synthesis DOI
Nao Tanaka, Joshua L. Zhu,

Oniya L. Valencia

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 31, 2023

β-Amino acids are useful building blocks of bioactive molecules, including peptidomimetics and pharmaceutical compounds. The current limited accessibility to β2,2-type amino which bear an α-quaternary center has their use in chemical synthesis biological investigations. Disclosed herein is the development a new N-heterocyclic carbene/photocatalyzed aminocarboxylation olefins, affording β2,2-amino esters with high regioselectivity. generation nitrogen-centered radicals derived from simple imides via sequence deprotonation single-electron oxidation allows for subsequent addition geminal-disubstituted olefins regioselectively. intermediate tertiary then cross-couple stabilized azolium-based radical generated situ efficiently construct quaternary centers. Mechanistic studies, Stern–Volmer fluorescence quenching experiments, support proposed catalytic cycle.

Language: Английский

Citations

18
Visible light-mediated NHC and photoredox co-catalyzed 1,2-sulfonylacylation of allenesviaacyl and allyl radical cross-coupling DOI
Lihong V. Wang, Jiaqiong Sun,

Jiuli Xia

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(4), P. 1047 - 1055

Published: Jan. 1, 2023

Visible light-mediated NHC and photoredox co-catalyzed radical 1,2-sulfonylacylation of allenes via cross-coupling between an allyl NHC-stabilized acyl radical.

Language: Английский

Citations

17
Radical Acylation of Alkenes by NHC‐Organocatalysis DOI Open Access
Qian Tang, Ding Du, Jian Gao

et al.

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(48)

Published: Oct. 11, 2023

Abstract N ‐Heterocyclic carbene (NHC) catalyzed radical‐radical reactions have been proven to be powerful strategies for assembling ketyl‐containing compounds via single electron transfer (SET) pathway under either thermal conditions or photoredox conditions. In this context, acylation of alkenes radical relay NHC‐organocatalysis has also opened a new window the difunctionalization construct valuable molecules in organic synthesis. review, advances and progress were summarized according different ways generation key NHC‐bound ketyl‐type radicals. Furthermore, reaction scopes, limitations mechanisms discussed based on types catalytic systems. Conclusions perspectives put forward at end.

Language: Английский

Citations

17