2,7-Dinitrophenanthrene-9,10-dione as a photosensitizer for the dehydrogenative lactonization of 2-arylbenzoic acids

This report describes the visible-light-induced C–H/COO–H oxidative coupling reaction of 2-arylbenzoic acids to synthesize benzo-3,4-coumarins by using 2,7-dinitrophenanthrene-9,10-dione as a photocatalyst.