Copper-catalyzed decarboxylative intramolecular C-O coupling: synthesis of 2-arylbenzofuran from 3-arylcoumarin

A copper-catalyzed decarboxylative intramolecular C-O coupling reaction was established. Under aerobic conditions in the presence of cupric chloride/1,10-phenathroline, a variety of 2-arylbenzofurans were prepared from 3-arylcoumarins in one-pot with yields from 26% to 84%.