Chemoselective electrochemical reduction of nitroarenes with gaseous ammonia
作者:Liu Chang、Jin Li、Na Wu、Xu Cheng
DOI:10.1039/d1ob00077b
日期:——
Valuable aromatic nitrogen compounds can be synthesized by reduction of nitroarenes. Herein, we report electrochemicalreduction of nitroarenes by a protocol that uses inert graphite felt as electrodes and ammonia as a reductant. Depending on the cell voltage and the solvent, the protocol can be used to obtain aromatic azoxy, azo, and hydrazo compounds, as well as aniline derivatives with high chemoselectivities
A reduction method involving sodium borohydride and cobalt sulfate dissolved in aqueous ethanol was developed and optimized. The established method reduces alkenes, alkynes, azides, nitriles, and nitroarenes at high rates (3–10 min) to afford good to excellent yields of the corresponding target reduction products.
The polyhedral nature of selenium-catalysed reactions: Se(<scp>iv</scp>) species instead of Se(<scp>vi</scp>) species make the difference in the on water selenium-mediated oxidation of arylamines
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyldiselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads
硒催化氧化在有机合成和生物学中备受追捧。在此,我们报告了我们对水硒介导的苯胺氧化的研究。在二苯基二硒化物或苯硒酸存在下,苯胺与过氧化氢反应,直接和选择性地获得硝基芳烃。另一方面,使用二氧化硒或亚硒酸钠会产生氧化偶氮芳烃。仔细的机理分析和77 Se NMR 研究表明,只有 Se( IV ) 物质,如苯过氧硒酸,是参与在水中运行并导致硝基芳烃的催化循环的活性氧化剂。虽然最近在有机溶剂中发生的其他硒催化氧化反应已被证明是通过 Se( VI) 关键中间体,苯胺在水中氧化成硝基芳烃没有。这些发现揭示了有机硒催化转化的多方面性质,并开辟了利用硒基催化的新方向。
Switchable Selectivity during Oxidation of Anilines in a Ball Mill
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
Gold-Catalyzed Direct Hydrogenative Coupling of Nitroarenes To Synthesize Aromatic Azo Compounds
作者:Xiang Liu、Hai-Qian Li、Sen Ye、Yong-Mei Liu、He-Yong He、Yong Cao
DOI:10.1002/anie.201404543
日期:2014.7.14
The azo linkage is a prominent chemical motif which has found numerous applications in materials science, pharmaceuticals, and agrochemicals. Described herein is a sustainable heterogeneous‐gold‐catalyzed synthesis of azo arenes. Available nitroarenes are deoxygenated and linked selectively by the formation of NN bonds using molecular H2 without any external additives. As a result of a unique and