A new approach for highly regioselective iodination of azobenzenes with alkyl iodide as the iodinating reagent enabled by Rh-catalyzedoxidativeC–Hactivation has been developed. By changing the oxidant, various mono- and di-iodinated azobenzenes were smoothly obtained in moderate to excellent yields, respectively. The preliminary mechanistic study reveals that the reaction process might undergo electrophilic
Palladium-Catalyzed Regioselective Halogenation of Aromatic Azo Compounds
作者:Xian-Tao Ma、Shi-Kai Tian
DOI:10.1002/adsc.201200902
日期:2013.1.25
A highly regioselective halogenation reaction of symmetrical and unsymmetrical aromatic azo compounds has been developed at roomtemperature or at 50 °C. In the presence of 5 mol% palladium diacetate and 0.5 equiv. of p-toluenesulfonic acid, a range of symmetrical aromatic azo compounds smoothly undergo monobromination with N-bromosuccinimide to give the corresponding unsymmetrical aromatic azo compounds