For the first time, reactions of acetophenone, 2,2,2-trifluoroacetophenone, fluorenone, and dinitrofluorenones with diphenyl and 4,4'-diphenoxybenzophenone in trifluoromethanesulfonic acid (TFSA) have been studied theoretically at the B3LY-P/cc-pvtz(-f)//B3LYP/6-31G* level of theory as a model reaction for a superelectrophile involving polycondensation. It was found that the introduction of electron-withdrawing groups into the carbonyl compound reduces activation and total reaction energies of the aromatic electrophilic substitution reaction. The enhancement of the reactivity of carbonyl compounds bearing electron-withdrawing groups is due to lowering of LUMO energy. The electrophiles having highly delocalized LUMO are less active in the reaction of electrophilic aromatic substitution due to decreases of local LUMO density at the reaction center. General rules for the design of reactive monomer are formulated on the basis of calculational results.