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
One-pot preparation of carbamoyl benzotriazoles and their applications in the preparation of ureas, hydrazinecarboxamides and carbamic esters
作者:Hui Mao、Huili Liu、Yawei Tu、Zhiyun Zhong、Xin Lv、Xiaoxia Wang
DOI:10.2298/jsc150126069m
日期:——
synthesized in one-pot from carboxylic acids, diphenylphosphorazidate (DPPA) and benzotriazole (BtH). The reactivity and applications of carbamoyl benzotriazoles were also explored. Carbamoyl benzotriazoles react smoothly with amino acids, hydrazines and alcohols respectively, thus providing facile access to the corresponding ureas, hydrazinecarboxamides and carbamicesters in good to excellent yields
Preparations of Trisubstituted Hydrazines and Pyrazolidines from <i>N</i>-(1-Benzotriazolylalkyl)hydrazines
作者:Alan R. Katritzky、Guofang Qiu、Baozhen Yang
DOI:10.1021/jo9709110
日期:1997.11.1
Reactions of N,N'-disubstituted hydrazines with benzotriazole and aldehydes give N-(alpha-benzotriazoylalkyl)-N,N'-disubstituted hydrazines which on treatment with organometallic reagents form N-alkyl-N,N'-disubstituted hydrazines in good yields. N-(Benzotriazolylalkyl)-N,N'-disubstituted hydrazines and electron-rich olefins, in the presence of zinc bromide catalyst, generate N,N'-disubstituted pyrazolidines
Two-Phase Dehydrogenation of Aryl Substituted Carbazide Compounds
作者:Yulu Wang、Chengjie Ru、Jianping Li、Hong Wang、Donglan Ma
DOI:10.1080/00397919408010178
日期:1994.6
Abstract Two-phase dehydrogenation, which is a new reaction of aryl substituted carbazide compounds, is described in this paper. Ten new azo compounds were synthesized by the reaction of aryl substituted carbazide compounds with a phenoxyl radical between two phases in good yields.
Unsymmetrical ureas and S-thiocarbamates were prepared in good to excellent yields by direct condensation of phenylurea with amines and thiols in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) without the addition of any additives. The [BMIM]BF4 ionic liquid is a mild medium and can be recycled and reused several times.