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

Abstract 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.