我们报告了一种使用安德森型多氧钼酸铁 ( III ) 作为催化剂和过氧化氢作为氧化剂在乙醇水溶液中氧化脱氢肼和二芳基胺的有效方法。以中等至极好的收率获得了一系列偶氮化合物和四芳基肼。反应条件和底物范围补充或优于更成熟的方案。此外,该催化剂在水中表现出良好的稳定性和重复使用性。初步的机理研究表明,该反应涉及一个自由基过程。
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
Chemoselective hydrogenation of nitrobenzenes activated with tuned Au/h-BN
作者:Qiuwen Liu、Yan Xu、Xiaoqing Qiu、Caijin Huang、Min Liu
DOI:10.1016/j.jcat.2018.12.008
日期:2019.2
catalytic process can be successfully conducted not only in N2 but also in air with isopropanol alcohol/KOH. Complete conversion of nitrobenzenes and high selectivity of azobenzenes and hydrazobenzenes have been achieved in onepot under N2 or air atmosphere. Furthermore, as usual unstable intermediates in the reduction process of nitrobenzenes, azobenzenes and hydrazobenzenes can be alternatively harvested
the electronic structure of the Ni-WC/C catalyst, and endowing the catalyst with switchable selectivity and high activity for the reduction of nitroarenes by hydrogenation. This synergistic multi-interfacial catalyst may offer a new way to design and explore highly efficient and selective catalysts for the controllable reduction of nitroarenes and similar hydrogenation reactions.
选择性还原硝基芳烃在工业化学生产中非常有价值。主要的还原产物通常是使用单组分贵金属或过渡金属催化剂获得的苯胺衍生物。但是,其他重要的产物,例如苯衍生物,总是要在苛刻的条件下和多个反应步骤中进行。在此,仅通过控制硝基芳烃与N 2 H 4 ·H 2的摩尔比,就可以实现高产率和高选择性地将硝基芳烃意外地还原为苯胺或苯衍生物。O,负载在碳上的镍-碳化钨复合纳米催化剂(Ni-WC / C)。一系列控制实验和密度泛函理论(DFT)计算表明,Ni和WC之间的多个界面可产生协同效应,显着调节Ni-WC / C催化剂的电子结构,并使催化剂具有可切换的选择性和选择性。氢化还原硝基芳烃的高活性。这种协同的多界面催化剂可能为设计和探索高效和选择性的催化剂提供新途径,以控制硝基芳烃的还原反应和类似的氢化反应。
Chemoselective Reductive Coupling of Nitroarenes with Magnesium in Methanol via Single Electron Transfer
作者:Jitender M. Khurana、Abhijit Ray
DOI:10.1246/bcsj.69.407
日期:1996.2
A chemoselective reductive coupling of nitroarenes using magnesium in methanol has been reported at ambient temperature. While the cyano, formyl, methoxycarbonyl, methyl, methoxy, phenyl, amino, and chloro groups are unaffected, iodo and bromo groups undergo dehalogenation but in a slower reaction than the coupling of nitro group. The coupling is believed to be proceeding via SET from Mg to nitroarenes
已经报道了在环境温度下使用甲醇中的镁进行硝基芳烃的化学选择性还原偶联。虽然氰基、甲酰基、甲氧基羰基、甲基、甲氧基、苯基、氨基和氯基团不受影响,但碘基和溴基团进行脱卤,但反应比硝基偶联慢。据信偶联是通过 SET 从 Mg 进行到硝基芳烃的。
Trichloroisocyanuric Acid Mediated Oxidative Dehydrogenation of Hydrazines: A Practical Chemical Oxidation To Access Azo Compounds
A highly efficient, metal-free, chemical oxidation of hydrazines has been implemented using environmentally friendly TCCA as oxidant. This benign protocol provides straightforward access to a wide range of azo compounds in THF in excellent yield. Altogether, 35 azo compounds were obtained in this way and scale-up preparations were performed. Additionally, a plausible mechanism was also proposed. Step-economical