Ruthenium(ii)-catalyzed C–H activation/lactonization of aromatic acids with diazonaphthoquinones: regioselective synthesis of polycyclic coumarin frameworks

Synthesis of biologically relevant dibenzo[ c , h ]chromen-6-one and dibenzo[ c , f ]chromen-5-one frameworks has been accomplished by leveraging a one-pot annulative coupling of aromatic acids with diazonaphthoquinones under ruthenium catalysis.