A new cobalt-catalyzed C–H bond activation of coumarins with aryl halides or pseudohalides
and carbon monoxide insertion to give various 3-aroylcoumarin derivatives is described.
It is the first time that CO as C1 feedstock is used as the coupling partners in cobalt-catalyzed
regioselective coumarin C–H functionalization reactions. Upon activation with manganese
powder, the Co catalyzes the C–H bond activation carbonylation reactions of aryl iodides,
bromides, and even triflates under mild conditions, providing the regioselective aroylated
products in moderate to good yields.
Key words
cobalt-catalyzed - C–H activation - carbon monoxide - carbonylation - 3-aroylcoumarin