Enantioselective Radical Ring-Opening Cyanation of Oxime Esters by Dual Photoredox and Copper Catalysis DOI
Jun Chen,

Peng‐Zi Wang,

Bin Lu

et al.

Organic Letters, Journal Year: 2019, Volume and Issue: 21(23), P. 9763 - 9768

Published: Nov. 20, 2019

Catalytic enantioselective chemical reactions involving highly reactive radical species remain largely unexplored. We report herein for the first time a novel ring-opening cyanation of redox-active oxime esters by dual photoreodox and copper catalysis. This mild protocol shows good functional group tolerance broad substrate scope, producing wide range optically active alkyl dinitriles with high yields excellent enantioselectivities, which are difficult to access traditionally.

Language: Английский

Photoredox-Catalyzed Sulfonylation ofO-Acyl Oximes via Iminyl Radicals with the Insertion of Sulfur Dioxide DOI
Jun Zhang, Xiaofang Li,

Wenlin Xie

et al.

Organic Letters, Journal Year: 2019, Volume and Issue: 21(13), P. 4950 - 4954

Published: June 10, 2019

A multicomponent sulfonylation of O-acyl oximes via iminyl radicals with the insertion sulfur dioxide under photoredox catalysis is achieved. This reaction oximes, potassium metabisulfite, alkenes, and nucleophiles visible-light irradiation efficient, giving rise to a range sulfones in moderate good yields. broad scope presented functional group compatibility.

Language: Английский

Citations

110

Recent Developments in Radical Cross‐Coupling of Redox‐Active Cycloketone Oximes DOI
Fang Xiao, Yu Guo, Yao‐Fu Zeng

et al.

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 363(1), P. 120 - 143

Published: Nov. 14, 2020

Abstract Recent years have witnessed a renaissance of radical cross‐coupling cycloketone oximes which served as active cyanoalkyl via ring fragmentation in various transformations. It provided an efficient and practical strategy to introduce groups into organic compounds without using toxic cyanide sources. In this review, comprehensive overview recent advances the field redox‐active oximes‐based cross‐couplings were covered. This review was categorized two broad parts: non‐photocatalyzed photocatalyzed according reaction conditions. Moreover, parts further divided several sub‐sections depending on nature bond formation. Some representative examples along with mechanisms also discussed. magnified image

Language: Английский

Citations

109

Recent advances for the photoinduced C C bond cleavage of cycloketone oximes DOI
Wei Xiao, Jie Wu

Chinese Chemical Letters, Journal Year: 2020, Volume and Issue: 31(12), P. 3083 - 3094

Published: July 18, 2020

Language: Английский

Citations

108

Reactivity Tuning for Radical–Radical Cross-Coupling via Selective Photocatalytic Energy Transfer: Access to Amine Building Blocks DOI
Vineet Kumar Soni, Sumin Lee,

Jihee Kang

et al.

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(11), P. 10454 - 10463

Published: Oct. 8, 2019

Reductive N–O bond cleavage has been widely explored for providing either N or O radical species various coupling processes. Despite significant advances, this photoredox pathway is less appealing due to poor atom economy owing the loss of one fragment during transformation. In regard, homolytic by an energy-transfer provide two key radicals would be highly desirable overcoming limitations use fragment. We report exclusive approach development a challenging radical–radical C(sp3)–N cross-coupling process reactivity-tuning catalytic system. The oxime esters in presence Ir complex produces acyloxy and iminyl radicals, which undergo decarboxylative yield valuable imines (typically 0.25 mol % cat. 1 h reaction time). Extensive photophysical electrochemical measurements, as well density functional theory studies, were carried out probe mechanism operation Dexter-type was revealed. choice solvent (EtOAc) concentration critical achieving selectivity reactivity process. synthetic utility method studying functionalized esters, including derivatives biologically active natural products drug molecules. Furthermore, situ transformations imine into pharmaceutically important amines also demonstrated, showcasing amine building blocks.

Language: Английский

Citations

101

No Making Without Breaking: Nitrogen-Centered Carbonylation Reactions DOI
Zhiping Yin, Jian‐Xing Xu, Xiao‐Feng Wu

et al.

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(11), P. 6510 - 6531

Published: May 13, 2020

Carbonylation, an efficient and straightforward approach for installing a carbonyl group into their parent compounds, is important area in modern organic synthesis. This Review outlines the recent advances development of nitrogen-centered carbonylation reactions, which consists two parts: nitrogen-center-directed reactions carbonylative C–N bonds activation. According to reaction mechanisms, two-electron- single-electron-mediated were systematically classified discussed detail. Different inert such as C(sp2)–H, C(sp3)–H, C–C, C(sp3)–N, C(sp2)–N can be activated ready transformation toward synthesis corresponding carbonyl-containing compounds.

Language: Английский

Citations

98

Nitriles as radical acceptors in radical cascade reactions DOI
Kai Sun, Qi‐Yan Lv, Ying‐Wu Lin

et al.

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 8(3), P. 445 - 465

Published: Oct. 26, 2020

The application of the cyano group as a radical acceptor in cascade reactions for construction various important heterocycles and carbocycles was summarized.

Language: Английский

Citations

97

Recent advances in cyclization reactions of unsaturated oxime esters (ethers): synthesis of versatile functionalized nitrogen-containing scaffolds DOI
Chen Chen, Jinghui Zhao, Xiaonan Shi

et al.

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(14), P. 1948 - 1969

Published: Jan. 1, 2020

We summarized recent advances in cyclization reactions of unsaturated oxime esters (ethers), which provide diversiform functionalized nitrogen-containing scaffolds.

Language: Английский

Citations

94

Enantioselective cyanation via radical-mediated C–C single bond cleavage for synthesis of chiral dinitriles DOI Creative Commons
Tao Wang, Yining Wang, Rui Wang

et al.

Nature Communications, Journal Year: 2019, Volume and Issue: 10(1)

Published: Nov. 26, 2019

Abstract Ring-opening reaction via selective cleavage of C–C bond is known as a powerful strategy for construction complex molecules. Complementary to the ionic process focusing on mostly small ring systems, radical-mediated offers solution further diverse enantioselective functionalization benefited from its mild conditions, whereas such asymmetric transformations are still limited three-membered rings so far. Herein, we describe ring-opening and cyanation four- five-membered cycloketone oxime esters access chiral 1,5- 1,6-dinitriles. Employment dual photoredox/copper catalysis essential cyclopentanone esters. Both reactions proceed under conditions giving dinitriles in high yields enantioselectivity with low catalyst loading broad substrate scope. The products can be converted valuable optically active diamides diamines. Mechanistic studies indicate that benzylic radical generated single involved catalytic cycle.

Language: Английский

Citations

93

Photoinduced, Copper-Catalyzed Radical Cross-Coupling of Cycloketone Oxime Esters, Alkenes, and Terminal Alkynes DOI
Jun Chen,

Bin‐Qing He,

Peng‐Zi Wang

et al.

Organic Letters, Journal Year: 2019, Volume and Issue: 21(11), P. 4359 - 4364

Published: May 29, 2019

A photoinduced, copper-catalyzed three-component radical cross-coupling of cycloketone oxime esters, alkenes, and terminal alkynes is described for the first time. Key to success this process was integration photoinduced iminyl radical-mediated C–C bond cleavage with conceptual simplicity cross-coupling. This protocol provides access cyanoalkyl-containing propargylic compounds in good yields.

Language: Английский

Citations

89

Oxime‐Derived Iminyl Radicals in Selective Processes of Hydrogen Atom Transfer and Addition to Carbon‐Carbon π‐Bonds DOI
Igor B. Krylov, Oleg O. Segida, Alexander S. Budnikov

et al.

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(10), P. 2502 - 2528

Published: March 25, 2021

Abstract Oximes represent one of the fundamental organic compound classes with a wide range synthetic applications. In last decade O ‐substituted oximes were recognized as synthetically available and versatile precursors iminyl radicals via one‐electron oxidation or reduction employing visible light photoredox catalysts, salts abundant metals (such Cu Fe), other convenient reagents. Iminyl are powerful synthons for various processes cyclization, ring‐opening, CH‐functionalization, coupling. The present review is focused on methods based oxime‐derived developed in few years excluding ring opening reactions cyclic that summarized recent publications. consists two main parts: (1) involving 1,n‐hydrogen atom transfer (n=5 most cases) (2) addition radical to carbon‐carbon π‐bond. magnified image

Language: Английский

Citations

70