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
Synthesis of Indazolones via Friedel–Crafts Cyclization of Blocked (Masked) <i>N</i>-Isocyanates
作者:Eslam B. Elkaeed、Jing An、André M. Beauchemin
DOI:10.1021/acs.joc.7b01607
日期:2017.9.15
are rare amphoteric reagents with high, but underdeveloped synthetic potential. Herein, we study the formation of indazolones by Friedel–Crafts cyclization of N-isocyanates usingblocked (masked) N-isocyanate precursors: the effect of the masking group and the reaction scope have been delineated. Substrate synthesis has also been improved using a reported copper-catalyzed coupling of arylbismuth(V) reagents
[reaction: see text] The addition of aryl- and heteroarylboronic acids to azocompounds is described. Copper salt catalysis was necessary to perform the reaction under mild conditions and high yields. Excellent regioselectivity was observed in addition to unsymmetricalazocompounds.
Copper Salt Catalyzed Coupling of Organobismuth Reagents and Azo Compounds
作者:Uno Mäeorg、Olga Tšubrik、Ksenija Kisseljova
DOI:10.1055/s-2006-950408
日期:2006.9
A new copper salt catalyzed C-N coupling is described. This smooth reaction between azo compounds and organobismuth reagents provides efficient and highly regioselective access to Boc-protected aryl hydrazines. The yields under optimized conditions are mostly excellent and the synthetic procedure is robust and simple.