Palladium-Catalyzed Synthesis of 4-Arylcoumarins Using Triarylbismuth Compounds as Atom-Efficient Multicoupling Organometallic Nucleophiles

Triarylbismuth compounds have been cross-coupled as atom-efficient multicoupling organometallic nucleophiles with 4-bromo- and 4-(trifluoromethylsulfonyloxy)coumarins under palladium catalysis conditions. These reactions afforded an array of 4-arylcoumarins in high yields. The general palladium protocol has been demonstrated to be efficient for the coupling of both bromide and triflate derivatives of coumarins with triarylbismuth reagents.