Direct phosphorylation of enamine and enamide with hydrogenevolution was realized via cobaloxime catalysis under visible-light irradiation. Control experiments and spectroscopic studies demonstrated a reductive quenching pathway of cobaloxime catalyst to produce phosphinoyl radical, which underwent cross-coupling with various enamines (and enamides) to give diverse β-phosphinoyl products in good to
A novel tert-butyl hydroperoxide (TBHP)-promoted oxidative C=C double-bond cleavage of enamines is described. Heating a solution of an electron-deficient enamine in chlorobenzene at 80 °C in the presence of TBHP for two hours led to cleavage of the C=Cbond. This study offers a new strategy to carry out C=O double-bond formation by the use of TBHP.
Isobutyl Nitrite-Mediated Synthesis of Quinoxalines through Double C−H Bond Amination of <i>N</i>
-Aryl Enamines
作者:Yan-Xiao Jiao、Lin-Su Wei、Chun-Yang Zhao、Kai Wei、Dong-Liang Mo、Cheng-Xue Pan、Gui-Fa Su
DOI:10.1002/adsc.201800928
日期:2018.11.16
An efficient and metal‐free double C−H bond amination of N‐aryl enamines using isobutyl nitrite (IBN) has been developed. This method enables the preparation of functionalized quinoxalines in good to excellent yields and tolerates a variety of N‐aryl enamines with diverse functional substituents. Mechanistic studies revealed the presence of a key β‐imino oxime ester intermediate. A quinoxaline derivative