82019-34-9Relevant academic research and scientific papers
Electro-reductive C-H cyanoalkylation of quinoxalin-2(1H)-ones
Ding, Ling,Liu, Yuxiu,Niu, Kaikai,Wang, Qingmin
supporting information, (2022/01/24)
Herein, we report a practical electro-reductive protocol for the direct C–H cyanoalkylation of quinoxalin-2(1H)-ones via iminyl radical-mediated ring opening. These mild reactions proceed under metal-, reductant-, and reagent-free conditions to provide synthetically useful cyanoalkylated quinoxalin-2(1H)-ones.
Photoinitiated Multicomponent Anti-Markovnikov Alkoxylation over Graphene Oxide
He, Haiping,Hu, Jian,Huang, Qing,Li, Fan,Liu, Liangxian,Nie, Liang,Peng, Xiangjun,Yang, Ming,Yao, Zhiyang,Zhou, Linyi
supporting information, (2022/01/20)
The development of graphene oxide–based heterogeneous materials with an economical and environmentally–friendly manner has the potential to facilitate many important organic transformations but proves to have few relevant reported reactions. Herein, we explore the synergistic role of catalytic systems driven by graphene oxide and visible light that form nucleophilic alkoxyl radical intermediates, which enable an anti-Markovnikov addition exclusively to the terminal alkenes, and then the produced benzyl radicals are subsequently added with N–methylquinoxalones. This photoinduced cascade radical difunctionalization of olefins offers a concise and applicable protocol for constructing alkoxyl–substituted N–methylquinoxalones.
Synthesis of (E)-Quinoxalinone Oximes through a Multicomponent Reaction under Mild Conditions
Xu, Jun,Yang, Huiyong,He, Lei,Huang, Lin,Shen, Jiabin,Li, Wanmei,Zhang, Pengfei
supporting information, p. 195 - 201 (2021/01/13)
Herein, a novel method for the gram-scale synthesis of (E)-quinoxalinone oximes through a multicomponent reaction under mild conditions is described. Such a transformation was performed under transition-metal-free conditions, affording (E)-oximes in a moderate-to-good yield through recrystallization. Our methodology demonstrates a successful combination of a Mannich-type reaction and radical coupling, providing a green and practical approach for the synthesis of potentially bioactive quinoxalinone-containing molecules.
K2S2O8-catalyzed highly regioselective amidoalkylation of diverse N-heteroaromatics in water under visible light irradiation
Chen, Zhi,Li, Jianjun,Ren, Quanlei,Song, Shengjie,Wang, Chaodong,Xu, Ning,Zhou, Jiadi
supporting information, p. 5753 - 5758 (2021/08/23)
A K2S2O8-catalyzed versatile C(sp2)-C(sp3) bond formation with N-heteroaromatics and γ-lactams/amides was developed. Quinoxalin-2(1H)-one, quinoline, isoquinoline, phthalazine, and benzothiazole reacted with γ-lactams/amides to give the corresponding C(sp2)-H amidoalkylation products in moderate to good yields with high regioselectivity. This visible-light-induced photocatalyst-free reaction was conducted in H2O at ambient temperature, which comply with the principles of "green chemistry". The new K2S2O8 catalytic mechanism was investigated with control experiments.
Visible Light-Promoted Radical Relay Cyclization/C-C Bond Formation of N-Allylbromodifluoroacetamides with Quinoxalin-2(1 H)-ones
Ye, Zhi-Peng,Liu, Fang,Duan, Xin-Yu,Gao, Jie,Guan, Jian-Ping,Xiao, Jun-An,Xiang, Hao-Yue,Chen, Kai,Yang, Hua
, p. 17173 - 17183 (2021/11/18)
A visible light-promoted radical relay of N-allylbromodifluoroacetamide with quinoxalin-2(1H)-ones was developed in which 5-exo-trig cyclization and C-C bond formation were involved. This protocol was performed under mild conditions to facilely offer a variety of hybrid molecules bearing both quinoxalin-2(1H)-one and 3,3-difluoro-γ-lactam motifs. These prepared novel skeletons would expand the accessible chemical space for structurally complex heterocycles with potential biological activities.
N, N, N', N'-Tetramethylethylenediamine-Enabled Photoredox-Catalyzed C-H Methylation of N-Heteroarenes
Liu, Fang,Ye, Zhi-Peng,Hu, Yuan-Zhuo,Gao, Jie,Zheng, Lan,Chen, Kai,Xiang, Hao-Yue,Chen, Xiao-Qing,Yang, Hua
, p. 11905 - 11914 (2021/08/24)
Aiming at the valuable methylation process, readily available and inexpensive N,N,N′,N′-tetramethylethylenediamine (TMEDA) was first identified as a new methyl source in photoredox-catalyzed transformation in this work. By virtue of this simple methylating reagent, a facile and practical protocol for the direct C-H methylation of N-heteroarenes was developed, featuring mild reaction conditions, broad substrate scope, and scalability. Mechanistic studies disclosed that a sequential photoredox, base-assisted proton shift, fragmentation, and tautomerization process was essentially involved.
Rapid alkenylation of quinoxalin-2(1H)-ones enabled by the sequential Mannich-type reaction and solar photocatalysis
Huang, Lin,Xu, Jun,He, Lei,Liang, Chenfeng,Ouyang, Yani,Yu, Yongping,Li, Wanmei,Zhang, Pengfei
supporting information, p. 3627 - 3631 (2021/05/03)
Herein, a rapid alkenylation of quinoxalin-2(1H)-ones enabled by a combination of Mannich-type reaction and solar photocatalysis is demonstrated. A wide range of functional groups are compatible, affording the corresponding products in moderate-to-good yields. Control experiments illustrate that the in situ generated 1O2 plays a central role in this reaction. This green and efficient strategy provides a practical solution for the synthesis of potentially bioactive compounds that containing a 3,4-dihydroquinoxalin-2(1H)-one structure.
Electro-oxidative C-H azolation of quinoxalin-2(1H)-ones
Ding, Ling,Hao, Yanke,Liu, Yuxiu,Niu, Kaikai,Song, Hongjian,Wang, Qingmin,Zhou, Pan
supporting information, p. 3246 - 3249 (2021/05/21)
We have developed a practical, general protocol for direct C-H azolation reactions of quinoxalin-2(1H)-ones by electro-oxidative cross-coupling. These mild reactions proceed under metal-, oxidant-, and reagent-free conditions to provide synthetically useful azolated quinoxalin-2(1H)-ones. Furthermore, the reactions can be carried out with a pencil lead as an electrode and a 3 V battery as a power source, revealing the remarkable flexibility of this protocol.
Electrochemical chlorination and bromination of electron-deficient C[sbnd]H bonds in quinones, coumarins, quinoxalines and 1,3-diketones
Yu, Dan,Ji, Ruixue,Sun, Zhihui,Li, Wenjie,Liu, Zhong-Quan
supporting information, (2021/11/16)
The electrochemistry-promoted chlorination and bromination of electron-deficient C[sbnd]H bonds was developed, using quinones, coumarins, quinoxalines and 1,3-diketones. This protocol features readily available and safe halogen sources (hydrochloric acid and KBr), high site-selectivity and mild reaction conditions. It could provide an efficient access to a series of chlorinated and brominated quinones, coumarins, quinoxalines and 1,3-diketones.
Visible-Light-Promoted Switchable Synthesis of C-3-Functionalized Quinoxalin-2(1H)-ones
Aganda, Kim Christopher C.,Hong, Boseok,Lee, Anna
supporting information, p. 1443 - 1448 (2021/01/26)
A visible-light-promoted synthesis of quinoxalin-2(1H)-ones has been developed using 9-mesityl-10-methylacridinium perchlorate as an organo-photocatalyst. The atmosphere-controlled method (Ar/air) enabled the selective synthesis of hydroxyl- and acyl-containing quinoxalin-2(1H)-ones under mild reaction conditions without the use of any metal catalysts or toxic reagents. A fluorescent labelling experiment showed that hydroxyl-containing quinoxalin-2(1H)-ones may have utility in various biological applications as potent fluorophores. (Figure presented.).
