Metal-free visible-light-initiated direct C3 alkylation of quinoxalin-2(1H)-ones and coumarins with unactivated alkyl iodides

Abstract

We report, for the first time, a visible-light-promoted direct C3 alkylation of quinoxalin-2(1H)-ones and coumarins using readily accessible unactivated alkyl iodides as alkylation reagents. By applying this new approach, a broad range of valuable 3-alkylated quinoxalin-2(1H)-ones and coumarins (55 examples) can be facilely obtained at room temperature, thus showing the wide utility of this protocol. Notably, this practical reaction occurs under metal- and external photocatalyst-free conditions and exhibits a broad substrate scope and high functional-group tolerance.