Nickel catalyzed intramolecular oxidative coupling: synthesis of 3-aryl benzofurans.

Recent research has been focused on the transition metal-catalyzed reactions. Herein we have developed nickel-catalyzed synthesis of 3-aryl benzofurans from ortho -alkenyl phenols via intramolecular dehydrogenative coupling. Notably, simple O 2 gas served as an oxidant, without using any sacrificial hydrogen acceptor. The strategy enabled the synthesis of 3-aryl benzofurans in good to excellent yields.