Nonstoichiometric polycondensation based on Friedel-Crafts acylation in superacids for the syntheses of aromatic polyketones

Based on Friedel-Crafts acylation, nonstoichiometric polycondensation was achieved using 4,4'-dicarboxydiphenyl ether and 2,2'dimethoxybiphenyl in trifluoromethanesulfonic acid. The decrease in the acylation reactivity of 2,2'-dimethoxybiphenyl by protonation and the increase in the acylation reactivity of the monoacylated species by deprotonation play a key role in successful nonstoichiometric polycondensations.