Copper(II)-catalyzed C3-acylation of quinoxalin-2(1H)-ones with methyl ketones via the formal decarbonylation of 1,2-diketones.

The inexpensive copper(II) bromide-catalyzed cross-dehydrogenative coupling/Kornblum oxidation/formal decarbonylation of N-substituted/unsubstituted quinoxalinones in DMSO is reported. It has offered a new technique for the cleavage of C(CO)-C(CO) bonds under base- and ligand-free conditions, allowing for the direct synthesis of a diverse range of C3-acylated quinoxalinones. This persulfate-peroxide-free catalytic method provides good yields, a broad substrate scope, and good tolerance to various functionalities.