t- BuONO-Mediated Direct C–H Functionalization for the Synthesis of Quinoxalin-2(1H)-ones in Water

A method has been established for the direct formation of C (sp²)–C (sp³) bonds between quinoxaline-2(1H)-one and indolin-2-one, mediated by tert-butyl nitrite ( t- BuONO). A highly efficient and feasible strategy based on a radical coupling reaction is proposed to achieve direct C-H functionalization between quinoxalin-2(1H)-ones and indolin-2-ones. This method provides a simple protocol, which can produce 3-(2-oxoindol-3-yl) quinoxalin-2(1H)-ones with moderate to good yields. It has the advantages of mild reaction conditions, good compatibility with functional groups, and environmental friendliness, thus providing a new pathway for the green synthesis of functional heterocyclic compounds.