Remote C(sp3)−H Acylation of Amides and Cascade Cyclization via N‐Heterocyclic Carbene Organocatalysis DOI
Qing‐Zhu Li, Rong Zeng, Fan Yang

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(15)

Published: Feb. 3, 2022

Abstract The direct functionalization of inert C(sp 3 )−H bonds under environmentally benign catalytic conditions remains a challenging task in synthetic chemistry. Here, we report an organocatalytic remote acylation amides and cascade cyclization through radical‐mediated 1,5‐hydrogen atom transfer mechanism using N‐heterocyclic carbene as the catalyst. Notably, diversity nitrogen‐containing substrates, including simple linear aliphatic carbamates ortho ‐alkyl benzamides, can be successfully applied to this system. With established protocol, over 120 examples functionalized δ‐amino ketones isoquinolinones with diverse substituents were easily synthesized up 99 % yield mild conditions. robustness generality strategy further highlighted by successful unactivated late‐stage modification pharmaceutical molecules. Then, asymmetric control radical reaction was attempted proven feasible newly designed chiral thiazolium catalyst, moderate enantioselectivity obtained at current stage. Preliminary mechanistic investigations several reactions, KIE experiments, computational studies shed light on mechanism.

Language: Английский

Recent advances in the chemistry and applications of N-heterocyclic carbenes DOI
Peter Bellotti, Maximilian Koy, Matthew N. Hopkinson

et al.

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(10), P. 711 - 725

Published: Sept. 3, 2021

Language: Английский

Citations

478
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
Recent advances in N-heterocyclic carbene-catalyzed radical reactions DOI
Lei Dai,

Song Ye

Chinese Chemical Letters, Journal Year: 2020, Volume and Issue: 32(2), P. 660 - 667

Published: Aug. 19, 2020

Language: Английский

Citations

153
Aryl radical-mediated N-heterocyclic carbene catalysis DOI Creative Commons

Yuki Matsuki,

Nagisa Ohnishi,

Yuki Kakeno

et al.

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: June 22, 2021

Abstract There have been significant advancements in radical reactions using organocatalysts modern organic synthesis. Recently, NHC-catalyzed initiated by single electron transfer processes actively studied. However, the reported examples limited to catalysis mediated alkyl radicals. In this article, NHC organocatalysis aryl radicals has achieved. The enolate form of Breslow intermediate derived from an aldehyde and thiazolium-type presence a base undergoes iodide, providing radical. catalytically generated could be exploited as arylating reagent for relay-type arylacylation styrenes hydrogen atom abstraction α-amino C(sp 3 )–H acylation secondary amides.

Language: Английский

Citations

143
Recent Progress toward the Construction of Axially Chiral Molecules Catalyzed by an N-heterocyclic Carbene DOI

Jiaming Wang,

Changgui Zhao, Jian Wang

et al.

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(20), P. 12520 - 12531

Published: Sept. 28, 2021

Axial chirality widely exists in natural products, pharmaceutical compounds, and other functional molecules; these axially chiral compounds also find wide utility as catalysts or ligands organic synthetic chemistry. Nevertheless, whereas significant progress has been made toward the synthesis of enantioenriched molecules over past two decades, strategies involving organocatalysis have only started to emerge recently. N-heterocyclic carbene (NHC) organocatalysts recognized be powerful tools for rapid construction complex molecular architectures. However, previous works mainly focused on assembly point recently it realized that asymmetric axial could achieved by using NHCs organocatalysts. This Perspective highlights developments advances scaffolds catalyzed NHCs. The aim this is provide an overview area serve a stepping stone future investigations.

Language: Английский

Citations

127
Tale of the Breslow intermediate, a central player in N-heterocyclic carbene organocatalysis: then and now DOI Creative Commons
Monika Pareek, Yernaidu Reddi, Raghavan B. Sunoj

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 12(23), P. 7973 - 7992

Published: Jan. 1, 2021

Molecular insights on the formation, detection, and even isolation of Breslow intermediate, which is most important species in N-heterocyclic carbene (NHC) catalysis, as obtained from experimental computational studies, are presented.

Language: Английский

Citations

111
Radical transformations for allene synthesis DOI Creative Commons
Yajun Li, Hongli Bao

Chemical Science, Journal Year: 2022, Volume and Issue: 13(29), P. 8491 - 8506

Published: Jan. 1, 2022

Allenes are valuable organic molecules that feature unique physical and chemical properties. They not only often found in natural products, but also act as versatile building blocks for the access of complex molecular targets, such pharmaceuticals, functional materials. Therefore, many remarkable elegant methodologies have been established synthesis allenes. Recently, more methods radical allenes developed, clearly emphasizing associated great synthetic values. In this perspective, we will discuss recent important advances

Language: Английский

Citations

79
Organic Photoredox-Catalyzed Silyl Radical Generation from Silylboronate DOI

Naho Takemura,

Yuto Sumida, Hirohisa Ohmiya

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(13), P. 7804 - 7810

Published: June 16, 2022

A visible-light-driven silyl radical generation method from silylboronates has been developed. The activation of with a catalytic amount mild base promoted the single-electron oxidation process to form radicals. Facile single electron transfer for borate readily occurred without hydrogen atom hydrosilane in presence various photoredox catalysts. Combining this protocol radical-mediated N-heterocyclic carbene catalysis enabled acylsilylation alkenes via relay generation. Furthermore, recent advanced methods synthesis significantly improved utility process.

Language: Английский

Citations

76
NHC and visible light-mediated photoredox co-catalyzed 1,4-sulfonylacylation of 1,3-enynes for tetrasubstituted allenyl ketones DOI Creative Commons
Lihong V. Wang,

Ruiyang Ma,

Jiaqiong Sun

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(11), P. 3169 - 3175

Published: Jan. 1, 2022

The modulation of selectivity highly reactive carbon radical cross-coupling for the construction C-C bonds represents a challenging task in organic chemistry. N-Heterocyclic carbene (NHC) catalyzed transformations have opened new avenue acyl With this method, selective an with alkyl efficient was successfully realized. However, reaction radicals vinyl has been much less investigated. We herein describe NHC and visible light-mediated photoredox co-catalyzed 1,4-sulfonylacylation 1,3-enynes, providing structurally diversified valuable tetrasubstituted allenyl ketones. Mechanistic studies indicated that ketyl are formed from aroyl fluorides via oxidative quenching photocatalyst excited state, generated chemo-specific sulfonyl addition to finally, key provides

Language: Английский

Citations

73
Diastereodivergent Desymmetric Annulation to Access Spirooxindoles: Chemical Probes for Mitosis DOI

Yu‐Hua Wen,

Fengrui Yang, Shuai Li

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 4199 - 4207

Published: Feb. 13, 2023

Spirooxindoles have emerged as promising architectures for engineering biologically active compounds. The diastereodivergent construction of unique scaffolds this type with full control continuous chiral centers including an all-carbon quaternary stereogenic center is yet to be developed. Here, we report unprecedented desymmetric [3 + 3] annulation oxabicyclic alkenes enals enabled by N-heterocyclic carbene (NHC)/Rh cooperative catalysis, leading a series enantiomerically enriched spirooxindole lactones excellent enantioselectivities (up >99% ee) and diastereoselectivities >95:5 dr). combined catalyst system comprises rhodium complex that controls the configuration at electrophilic carbon NHC nucleophilic oxindole-containing carbon; thus, four stereoisomers products can readily obtained simply switching configurations two catalysts. Transformations spirooxindoles delivered synthetically useful Importantly, those arrested mammalian cells in mitosis exhibited potent antiproliferative activities against HeLa cells. Significantly, both absolute relative exert prominent effects on bioactivities, underscoring great importance catalytic asymmetric synthesis beyond creating tools exploration structure–activity relationships.

Language: Английский

Citations

47