Preparation of 4,7-Dibromobenzo[b]thiophene as a Versatile Building Block and Synthetic Application to a Bis(ethynylthienyl)oligoarene System

Abstract Benzo[b]thiophene, 4,7-dibromobenzo[b]thiophene, thieno[3,2-b]thiophene, and 3-bromothieno[3,2-b]thiophene were prepared by AuCl-catalyzed cyclization of (t-butylsulfanyl)(ethynyl)benzenes or (t-butylsulfanyl)(ethynyl)thiophenes. Several reactions of 4,7-dibromobenzo[b]thiophene were investigated, including metallation and cross coupling reactions.