Catalysis by polymer complexes. VIII. Enhanced nucleophilic reactivity of hydroxamate anions bound to quaternized polyethylenimines and related compounds

Water‐soluble polyethylenimine derivatives composed only of the tertiary amine and quaternary ammonium groups were prepared by methylation and quaternization of commercial polyethylenimine. The reaction of the hydrophobic hydroxamate anion and p‐nitrophenyl acetate (aqueous solution, 30°C) was more than 100 times accelerated by the polyethylenimine partly quaternized by stearyl bromide. The polymers quaternized by less hydrophobic groups or by the stearyl and methyl groups were much less effective. The former polymer also accelerated decomposition of the acetyl hydroxamate up to 25 times. The rate‐enhancing effect of these polyethylenimine derivatives appeared to be produced by the general, hydrophobic microenvironment without regard to the peculiar structural characteristics of polyethylenimine. The effect of fully quaternized triethylenetetramine was similarly studied.