Ketones from aldehydes via alkyl C(sp3)−H functionalization under photoredox cooperative NHC/palladium catalysis DOI Creative Commons
Haiying Wang,

Xin-Han Wang,

Bang‐An Zhou

et al.

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

Published: July 8, 2023

Direct synthesis of ketones from aldehydes features high atom- and step-economy. Yet, the coupling with unactivated alkyl C(sp3)-H remains challenging. Herein, we develop via functionalization under photoredox cooperative NHC/Pd catalysis. The two-component reaction iodomethylsilyl ether gave a variety β-, γ- δ-silyloxylketones 1,n-HAT (n = 5, 6, 7) silylmethyl radicals to generate secondary or tertiary following ketyl NHC three-component addition styrenes corresponding ε-hydroxylketones generation benzylic by radicals. This work demonstrates radical catalysis, provides two three component reactions for functionalization. synthetic potential this protocol was also further illustrated late-stage natural products.

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
Synthetic Advantages of Defluorinative C−F Bond Functionalization DOI Creative Commons
Leidy V. Hooker, Jeffrey S. Bandar

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

Published: Aug. 22, 2023

Abstract Much progress has been made in the development of methods to both create compounds that contain C−F bonds and functionalize bonds. As such, are becoming common versatile synthetic functional handles. This review summarizes advantages defluorinative functionalization reactions for small molecule synthesis. The coverage is organized by type carbon framework fluorine attached mono‐ polyfluorinated motifs. main challenges, opportunities advances discussed each class organofluorine. Most text focuses on case studies illustrate how defluorofunctionalization can improve routes targets or properties enable unique mechanisms reactions. broader goal showcase incorporating exploiting design routes, improvement specific advent new methods.

Language: Английский

Citations

57
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
Diastereoselective Radical Aminoacylation of Olefins through N-Heterocyclic Carbene Catalysis DOI

Wen-Deng Liu,

Woojin Lee,

Hanyu Shu

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(49), P. 22767 - 22777

Published: Nov. 24, 2022

There have been significant advancements in radical-mediated reactions through covalent-based organocatalysis. Here, we present the generation of iminyl and amidyl radicals via N-heterocyclic carbene (NHC) catalysis, enabling diastereoselective aminoacylation trisubstituted alkenes. Different from photoredox single electron transfer deprotonated Breslow intermediate to O-aryl hydroxylamine generates an NHC-bound ketyl radical, which undergoes diastereocontrolled cross-coupling with prochiral C-centered radical. This operationally simple method provides a straightforward access variety pyrroline oxazolidinone heterocycles vicinal stereocenters (77 examples, up >19:1 d.r.). Electrochemical studies acyl thiazolium salts support our reaction design highlight reducing ability Breslow-type derivatives. A detailed computational analysis this organocatalytic system suggests that radical–radical coupling is rate-determining step, π–π stacking interaction between radical intermediates subtly controls diastereoselectivity.

Language: Английский

Citations

56
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
Regiodivergent C−H Acylation of Arenes by Switching from Ionic‐ to Radical‐Type Chemistry Using NHC Catalysis DOI

Jannik Reimler,

Xiaoye Yu,

Nico Spreckelmeyer

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(27)

Published: April 24, 2023

The Friedel-Crafts acylation reaction, which belongs to the class of electrophilic aromatic substitutions is a highly valuable and versatile reaction in synthesis. Regioselectivity predictable determined by electronic as well steric factors (hetero)arene substrate. Herein, radical approach for arenes heteroarenes presented. C-H achieved through mild cooperative photoredox/NHC catalysis with cross-coupling an arene cation NHC-bound ketyl key step. As compared classical acylation, regiodivergent outcome observed upon switching from ionic mode. In these divergent reactions, aroyl fluorides act reagents both process.

Language: Английский

Citations

34
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