Dual C-C bond formation was accomplished in one pot for the synthesis of a wide variety of indanones mediated by triflic acid. The reaction proceeds via an initial Michael-addition-type Friedel-Crafts alkylation followed by intramolecular acylation (cyclization). Significantly, the method was also successfully employed on more reactive β-diarylcinnamates using slightly different conditions © Georg Thieme Verlag Stuttgart New York Synthesis 2015.