A unique stepped multifunctionality of perfluorinated aryl compound for the first time was studied by using model reactions between 2,5-dipentafluorophenyl-1,3,4-oxadiazole (FPOx) and mono functional p-cresol at different reaction conditions. Four distinctively different levels of reactivity were discovered for the para and ortho C-F of FPOx, which could be easily triggered by the reaction temperature in the range of r.t. to 160 degrees C. C-F of all levels of reactivity could react quantitatively with nucleophiles (such as phenoxide); and by controlling the reaction conditions, the low-level-reactivity C-F would not interfere with the reaction of C-F of higher reactivity. Application of this multistepped reactivity of FPOx in quantitative postpolymerization functionalization of polymer was successfully demonstrated. Stoichiometric amount of p-cresol, with the molar feed ratio of p-cresol in relative to the repeat unit of the polymer of FPOx and 6F-BPA in the range of 1-4, could be readily grafted onto the polymer by simply controlling the reaction temperature. FPOx-based, versatile one-pot synthesis of high molecular-weight grafted polymers with well-controlled structures and topologies were also demonstrated. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2423-2433, 2011