Metal-free C(3)-H arylation of coumarins promoted by catalytic amounts of 5,10,15,20-tetrakis(4-diethylaminophenyl)porphyrin

The metal-free C-H arylation of coumarins was achieved in the presence of catalytic amounts of 5,10,15,20-tetrakis(4-diethylaminophenyl)porphyrin. This mild and environmentally friendly Meerwein arylation provided facile access to a broad variety of 3-arylcoumarins in synthetically useful yields.