Brønsted acid-catalyzed radical C H functionalization of acetone with N-allyl anilines to give 3-(3-oxobutyl)indolines

•Brønsted acid-assisted strategy for ketonic radical generation involving K2S2O8.•First H+-catalyzed CH functionalization of acetone with unactivated alkenes.•Difunctionalization of unactivated alkenes.•3-(3-Oxobutyl)indolines provided.•exo-Selectivity and broad substrate scope.