Abstract Phosphoruspentoxide–methanesulfonicacid (P2O5–MsOH) mediated electrophilic aromatic substitution diaroylation of 2,2′‐dimethoxy‐1,1′‐binaphthyl (1) with several aromatic carboxylic acids (3) proceeds to afford 6,6′‐diaroylated adducts (4) as single regioisomers.