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
Aerobic Oxidation of Alkyl 2-Phenylhydrazinecarboxylates Catalyzed by CuCl and DMAP
作者:Min Hye Kim、Jinho Kim
DOI:10.1021/acs.joc.7b03119
日期:2018.2.2
various fruitful organic reactions such as a catalytic Mitsunobu reaction were reported by virtue of alkyl 2-phenylazocarboxylates, however, the synthesis of alkyl 2-phenylazocarboxylates largely depended on the stoichiometric use of toxic oxidants. In this manuscript, an environment-friendly aerobic oxidative transformation of alkyl 2-phenylhydrazinecarboxylates to alkyl 2-phenylazocarboxylates is
Reduction of hydrazines to amines with low-valent titanium reagent
作者:Fang Ren、Yan Zhang、Lan Hu、Meiming Luo
DOI:10.3998/ark.5550190.0014.313
日期:——
The N,N bond cleavage in hydrazines to amines via low-valenttitaniumreagent prepared in situ by treatment of TiCl4 with Mg powder in THF or CH2Cl2-Et2O is described. The reaction proceeds smoothly under mild conditions to afford amines in good to excellent yields with diverse functional group tolerance such as chloride, methoxyl, benzyloxyl, ester, acyl, as well as C,C double bonds and benzyl-nitrogen
A convenient method for the synthesis of 2-arylazocarboxylates from 2-arylhydrazinecarboxylates by aerobicoxidation with ironphthalocyanine is described. The reaction is applicable to oxidative activation of 1-acyl-2-phenylhydrazines. Some preliminary experiments suggest Michaelis–Menten kinetics and participation of radical species in the reaction mechanism.
Novel, Efficient and Regiospecific Alkylation/Arylation/Heteroarylation of Unsymmetrical Azo Compounds
作者:Uno Mäeorg、Olga Tšubrik、Rannar Sillard
DOI:10.1055/s-2006-926331
日期:——
Excellent regioselectivity is observed in the addition of diverse organometallic nucleophiles to unsymmetricalazocompounds. Primary/secondary/tertiary alkyl, aryl and heteroaryl substituents were introduced this way in high yields.