Iron-catalyzed intramolecular o-arylation: synthesis of 2-aryl benzoxazoles.

A practical iron-catalyzed intramolecular O-arylation reaction and its application in the synthesis of benzoxazole derivatives, starting from the readily available 2-haloanilines, is presented. The key cyclization step involves the use of a combination of the cheap and environmentally friendly FeCl(3) and 2,2,6,6-tetramethyl-3,5 heptanedione (TMHD) as the catalyst system.