Direct access to acylated quinoxalin-2(1H)-one N-oxides enabled by the Cu(i)/TBHP system

Abstract

Slight modification of nitrogen-containing heterocycles to obtain structurally novel compounds is important in the search for valuable biological molecules. In this study, we established a simple and practical method for the synthesis of diverse N-oxides of C3-acylated quinoxalin-2(1H)-ones. Under Cu(I)/TBHP conditions, the simultaneous construction of C–C and N–O bonds to obtain quinoxalin-2(1H)-one oxides via C–H activation and radical relay reaction was disclosed for the first time.