A Selectfluor-promoted oxidative
coupling of quinoxalin-2(1H)-ones with alcohols,
amines, thiols, and selenols leading
to the formation of C–O, C–N, C–S, and C–Se
bonds has been developed. The protocol provided good to excellent
(53–95%) yields of a wide range of quinoxalin-2(1H)-ones decorated with alkoxy, alkylamino, alkylthio, and arylselenyl
groups at the C3-position under metal- and photocatalyst-free conditions.
The reaction is believed to proceed through a radical pathway. A broad
substrate scope including bioactive molecules, mild reaction conditions,
readily available coupling partners, high yields, scalability, step-economy,
and metal- and photocatalyst-free conditions are the highlighting
features of the method. The synthetic utility of the developed protocol
was demonstrated by gram-scale synthesis, C3-alkoxylation of quinoxaline-2(1H)-one with natural alcohols, and synthesis of aldose reductase
(ALR2) inhibitor and histamine-4 receptor antagonist in good yields.