Hydrogen peroxide based oxidation of hydrazines using HBr catalyst
作者:Jian Wang、Zichao Ma、Wanting Du、Liming Shao
DOI:10.1016/j.tet.2021.132546
日期:2021.12
Azo compounds (RN = NR′) are an important class of organic molecules that find wide application in organic synthesis. Herein, we report an efficient, practical and metal-free oxidation of hydrazines (RNH-NHR’) to azo compounds using 5 mol% HBr and hydrogen peroxide as terminal oxidant. This new method has been demonstrated by 40 examples with excellent yields. In addition, we showcased two examples
Photoinduced<i>N</i>-Methylation and<i>N</i>-Sulfonylation of Azobenzenes with DMSO Under Mild Reaction Conditions
作者:Ning Xu、Yan Zhang、Wei Chen、Pinhua Li、Lei Wang
DOI:10.1002/adsc.201701548
日期:2018.3.20
with dimethyl sulfoxide (DMSO) was developed in the absence of an external photosensitizer under mild conditions. The reactions underwent smoothly to generate the corresponding products in high yields through a radical addition using the starting material azobenzene as a photosensitizer. This strategy features simple operation, easily available starting materials and DMSO acting as both methylating
The Photochemical Reduction of Nitrobenzene and Its Reduction Intermediates. XI. The Photochemical Reduction of Azobenzene in Isopropyl Alcohol
作者:Shizunobu Hashimoto、Koji Kano
DOI:10.1246/bcsj.45.852
日期:1972.3
The photochemical reduction of azobenzene in isopropylalcohol has been investigated. The n-π* transition of azobenzene caused only the cis-trans photoisomerization, while the n-π* transition caused both photoisomerization and photoreduction. The reduction product was hydrazobenzene. The photoreduction was accelerated by a small amount of oxygen and was quenched by 1,3-pentadiene. The photoreduction
Aerobic Oxidation of Pd<sup>II</sup> to Pd<sup>IV</sup> by Active Radical Reactants: Direct C–H Nitration and Acylation of Arenes via Oxygenation Process with Molecular Oxygen
oxidative C–H nitration and acylation of arenes with simple and readily available tert-butyl nitrite (TBN) and toluene as the radical precursors has been developed. Molecular oxygen is employed as the terminal oxidant and oxygen source to initiate the active radical reactants. Many different directing groups such as pyridine, pyrimidine, pyrazole, pyridol, pyridylketone, oxime, and azo groups can be employed
已经开发了钯催化的好氧氧化C–H硝化和芳烃与简单易用的亚硝酸叔丁酯(TBN)和甲苯作为自由基前体的酰化反应。分子氧被用作末端氧化剂和氧源以引发活性自由基反应物。在这些新颖的转化中可以使用许多不同的导向基团,例如吡啶,嘧啶,吡唑,吡啶醇,吡啶基酮,肟和偶氮基团。通过自由基过程的Pd II / Pd IV催化循环是这些氧化的CH–H硝化和酰化反应的最可能途径。
Rhodium‐Catalyzed Cascade Annulation Reaction
<i>via</i>
C−H Activation of Azobenzenes with Terminal Alkynes: A Synthesis of Indolo[1,2‐
<i>b</i>
]cinnolines
作者:Shuwei Zhang、Biying Wang、Xiaodong Jia、Yu Yuan
DOI:10.1002/adsc.201801183
日期:2019.2
The approach for direct synthesis of Indolo[1,2‐b]cinnolines was first developed from azobenzenes and terminal alkynes by rhodium‐catalyzed cascadeannulationreaction. In this reaction, the C−C and C−N bonds can be simultaneously constructed viaC−Hactivation to afford the desired products in moderate to good yields.
直接合成吲哚[1,2- b ] cinnolines的方法是通过铑催化的级联环化反应由偶氮苯和末端炔烃开发的。在该反应中,CC和CN键可通过CH活化同时构建,以中等至良好的产率提供所需的产物。