the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil
A niobium-catalyzed coupling reaction of α-keto acids with <i>ortho</i>-phenylenediamines: synthesis of 3-arylquinoxalin-2(1<i>H</i>)-ones
作者:Camila Ebersol、Nicole Rocha、Filipe Penteado、Márcio S. Silva、Daniela Hartwig、Eder J. Lenardão、Raquel G. Jacob
DOI:10.1039/c9gc02662b
日期:——
valuable 3-arylquinoxalin-2(1H)-ones was developed, by the reaction of α-keto acids with ortho-phenylenediamines in the presence of ammonium niobium oxalate (ANO) as a catalyst. The reactions were conducted in only 10 min under ultrasonic irradiation as an alternative energy source, affording water as the only co-product. A total of twenty-three different 3-arylquinoxalin-2(1H)-ones were selectively obtained
在草酸铌铵(ANO)存在下,通过α-酮酸与邻苯二胺的反应,开发了一种获得有价值的3-芳基喹喔啉-2(1 H)-酮的通用方法。作为替代能源,在超声辐射下仅需10分钟即可进行反应,仅提供水作为副产物。通过该原子有效方案,以良好至优异的产率选择性地获得了总共二十三种不同的3-芳基喹喔啉-2(1 H)-。另外,使用1 H– 15 N HMBC实验来揭示所得产物的区域异构现象。
Electrochemical Arylation of Electron‐Deficient Arenes through Reductive Activation
作者:Pan Wang、Zhenlin Yang、Ziwei Wang、Chenyang Xu、Lei Huang、Shengchun Wang、Heng Zhang、Aiwen Lei
DOI:10.1002/anie.201909600
日期:2019.10.28
An electrochemical method has been developed to achieve arylation of electron-deficientarenes through reductive activation. Various electron-deficientarenes and aryldiazonium tetrafluoroborates are amenable to this transformation within the conditions of an undivided cell, providing the desired products in up to 92 % yield. Instead of preparing diazonium reagents, these reactions can begin from anilines
Ambient and aerobic carbon–carbon bond cleavage toward α-ketoester synthesis by transition-metal-free photocatalysis
作者:Qing Yu、Yating Zhang、Jie-Ping Wan
DOI:10.1039/c9gc01357a
日期:——
available enaminones enabling efficient synthesis of α-ketoesters is developed. The reactions showing general tolerance to the reactions of primary and secondaryalcohols proceed well under air via Rose Bengal (RB)-based photocatalysis. Particularly, this mild synthetic method has been discovered to tolerate various polyhydroxylated substrates such as phenolic alcohol, diols and triols with an excellent
Transition Metal-Free Direct C-3 Arylation of Quinoxalin-2(1<i>H</i>
)-ones with Arylamines under Mild Conditions
作者:Jinwei Yuan、Shuainan Liu、Lingbo Qu
DOI:10.1002/adsc.201701058
日期:2017.12.11
A transition metal‐freedirect C‐3 arylation of quinoxalin‐2(1H)‐ones with arylamines has been explored. This reaction proceeded smoothly through a radical process undermildconditions and produced the desired arylation products in good yields. The reactions proceeded efficiently with a broad range of substrates and functional group tolerance.