Synthesis of thieno[3,2-b]benzofurans by palladium-catalyzed intramolecular C-H/C-H coupling

Abstract

The intramolecular C-H/C-H coupling of 3-aryloxythiophenes and 3-aryloxybenzo[b]thiophenes has been found to occur effectively in the presence of Pd(TFA) 2 and AgOAc as catalyst and oxidant, respectively, to afford the corresponding cyclized products, thieno[3,2-b]benzofurans and [1]benzothieno[3,2-b]benzofurans.