51789-21-0Relevant academic research and scientific papers
Visible-Light-Promoted Diboron-Mediated Transfer Hydrogenation of Azobenzenes to Hydrazobenzenes
Song, Menghui,Zhou, Hongyan,Wang, Ganggang,Ma, Ben,Jiang, Yajing,Yang, Jingya,Huo, Congde,Wang, Xi-Cun
, p. 4804 - 4811 (2021/04/06)
A visible-light-promoted transfer hydrogenation of azobenzenes has been developed. In the presence of B2pin2 and upon visible-light irradiation, the reactions proceeded smoothly in methanol at ambient temperature. The azobenzenes with diverse functional groups have been reduced to the corresponding hydrazobenzenes with a yield of up to 96%. Preliminary mechanistic studies indicated that the hydrogen atom comes from the solvent and the transformation is achieved through a radical pathway.
Convenient semihydrogenation of azoarenes to hydrazoarenes using H2
Sahoo, Manoj K.,Sivakumar, Ganesan,Jadhav, Sanjay,Shaikh, Samrin,Balaraman, Ekambaram
supporting information, p. 5289 - 5293 (2021/06/30)
The high atom-economical and eco-benign nature of hydrogenation reactions make them much more superior to conventional reduction and transfer hydrogenation. Herein, a convenient and highly selective hydrogenation reaction of azoarenes using molecular hydrogen to access diverse hydrazoarenes is reported. The present catalytic method is general and operationally simple, and it operates under exceedingly mild conditions (room temperature and 1 atm of hydrogen pressure). The reusability of catalysts used in this method is also successfully demonstrated.
Hydrogen peroxide based oxidation of hydrazines using HBr catalyst
Du, Wanting,Ma, Zichao,Shao, Liming,Wang, Jian
, (2021/11/18)
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 of the one-pot sequential reactions involving our hydrazine oxidation/hydrolysis/Heck reaction or Cu-catalyzed N-arylation with aryl boronic acid. The distinct advantages of this protocol include metal-free catalysis, waste prevention, and easy operation.
Visible-light-promoted oxidative dehydrogenation of hydrazobenzenes and transfer hydrogenation of azobenzenes
Wang, Xianya,Wang, Xianjin,Xia, Chungu,Wu, Lipeng
supporting information, p. 4189 - 4193 (2019/08/07)
Azo compounds are widely used in the pharmaceutical and chemical industries. Here, we report the use of a non-metal photo-redox catalyst, Eosin Y, to synthesize azo compounds from hydrazine derivatives. The use of visible-light with air as the oxidant makes this process sustainable and practical. Moreover, the visible-light-driven, photo-redox-catalyzed transfer hydrogenation of azobenzenes is compatible with a series of hydrogen donors such as phenyl hydrazine and cyclic amines. Compared with traditional (thermal/transition-metal) methods, our process avoids the issue of over-reduction to aniline, which extends the applicability of photo-redox catalysis and confirms it as a useful tool for synthetic organic chemistry.
Dehydrogenation of the NH?NH Bond Triggered by Potassium tert-Butoxide in Liquid Ammonia
Wang, Lei,Ishida, Akiko,Hashidoko, Yasuyuki,Hashimoto, Makoto
supporting information, p. 870 - 873 (2017/01/14)
A novel strategy for the dehydrogenation of the NH?NH bond is disclosed using potassium tert-butoxide (tBuOK) in liquid ammonia (NH3) under air at room temperature. Its synthetic value is well demonstrated by the highly efficient synthesis of aromatic azo compounds (up to 100 % yield, 3 min), heterocyclic azo compounds, and dehydrazination of phenylhydrazine. The broad application of this strategy and its benefit to chemical biology is proved by a novel, convenient, one-pot synthesis of aliphatic diazirines, which are important photoreactive agents for photoaffinity labeling.
