Visible-light-promoted/PIFA-mediated direct C−H acylation of quinoxalin-2(1H)-ones with aldehydes

With aldehydes as the radical precursors under visible-light irradiation, a simple and mild C-H acylation reaction of quinoxa-lin-2(1H)-ones has been achieved. A wide variety of functional groups could be incorporated into the products by employing diverse aldehydes and quinoxalin-2(1H)-one derivatives. Also, this method was applied to the modification of natural mole-cule and pharmaceutically relevant compound. Mechanistic study revealed that HAT process occurred in the acylation re-action for the generation of acyl radical, and PIFA ([bis(trifluoroacetoxy)iodo]benzene) acted both as the photosensitizer and oxidant in this reaction.