Herein we report an effective and simple preparation method of substituted azoxybenzenes by reductive dimerization of nitrosobenzenes. This procedure requires no additional catalyst/reagent and can be applied to substrates with a wide range of substitution patterns.
Novel chemoselective hydrogenation of aromatic nitro compounds over ferric hydroxide supported nanocluster gold in the presence of CO and H2O
作者:Lequan Liu、Botao Qiao、Zhengjian Chen、Juan Zhang、Youquan Deng
DOI:10.1039/b816547e
日期:——
Chemoselective hydrogenation of aromatic nitro compounds were first efficiently achieved over Au/Fe(OH)x at 100–120 °C for 1.5–6 h (depending on different substrates) in the presence of CO and H2O.
Controlling the type of indium salt and hydrosilane enables a highly selective reduction of aromatic nitro compounds into three coupling compounds, azoxybenzenes, azobenzenes and diphenylhydrazines, and one reductive compound, anilines.
for the direct oxidation of anilines to the corresponding azo and azoxy homocoupling products by using a planetary ballmill was developed. Various oxidants and grinding auxiliaries were tested and a variety of substituted anilines were investigated. It was possible to form chemoselectively either azo, azoxy, or the nitro compounds from reaction of aromatic anilines. The selectivity of the solvent‐free
Mild, selective and switchable transfer reduction of nitroarenes catalyzed by supported gold nanoparticles
作者:Xiang Liu、Sen Ye、Hai-Qian Li、Yong-Mei Liu、Yong Cao、Kang-Nian Fan
DOI:10.1039/c3cy00533j
日期:——
A highly versatile and flexible gold-based catalytic system has been developed for the controlled and selective transfer reduction of nitroarene using 2-propanol as a convenient hydrogen source under mild conditions. Depending on the specific reaction conditions, multiple products including azoxyarenes, symmetric or asymmetric azoarenes and anilines can be obtained respectively via a controlled reduction of the nitro aromatics with good to excellent yields in the presence of a reusable mesostructured ceria-supported gold (Au/meso-CeO2) catalyst. The overall operational simplicity, high chemoselectivity, functional-group tolerance and reusability of the catalyst make this approach an attractive and reliable tool for organic and process chemists.