Base-Mediated Visible-Light-Driven\nC–H Arylation\nof Quinoxalin-2(1<i>H</i>)‑Ones in Ethanol

Prior methods for visible-light-driven C–H arylation\nof\nquinoxalin-2(1<i>H</i>)-ones relied on external photocatalysts.\nHerein, we report a photocatalyst-free approach for this arylation.\nIn this approach, β-dicarbonyl iodonium ylides, combined with <i>t</i>-BuOK in ethanol, act as aryl precursors, forming electron\ndonor–acceptor (EDA) complexes. These complexes enhance light\nabsorption, facilitating efficient single electron transfer and aryl\nradical formation. Consequently, various quinoxalin-2(1<i>H</i>)-ones undergo precise and efficient arylation without external photocatalysts.\nThis protocol exhibits excellent tolerance toward diverse functional\ngroups, with mild reaction conditions and eco-friendly solvents, revealing\na high Ecoscale value.