Selective Palladium‐Catalysed ipso Arylation of α,α‐Disubstituted Benzo[b]thien‐2‐ylmethanols with Aryl Bromides using PCy3 as Ligand

Abstract α,α‐Diphenylbenzo[b]thien‐2‐ylmethanol was treated with a series of aryl bromides in the presence of palladium(II) acetate and tricyclohexylphosphane to give the appropriate 2‐aryl‐benzo[b]thiophenes in good to excellent yield with concomitant formation of benzophenone. The reaction wassuccessfully extended to α,α‐diphenylbenzo[b]thien‐3‐ylmethanol, although in certain cases the transformation was biased by concurrent ortho arylation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)