General approach to benzo[b]thiophenes, benzo[b]furans, and dibenzofurans via gold-catalyzed cyclization of 1-heteroarylalka-2,3-dienyl acetates

An efficient and mild route to a series of benzo[b]thiophenes, benzo[b]furans, and dibenzofurans through gold-catalyzed benzannulation of 1-heteroarylalka-2,3-dienyl acetates was developed. Two possible pathways of this reaction involving gold carbene and aryl gold intermediates have been proposed on the basis of mechanistic studies.