Multifunctional imidazole-derived polymeric catalyst for dephosphorylation reactions potentiated by cationic and anionic micelles

Abstract

Results confrm the catalytic potential of imidazole groups anchored on the polymeric backbone of polyvinylimidazole (PVI) in dephosphorylation reactions with di- and tri-phosphoesters, promoting impressive enhancements up to 107-fold. We propose the imidazole groups on PVI react by nucleophilic catalysis (neutral specie) with a phosphate triester and bifunctionally by general acid-nucleophilic catalysis (bipolar species) with a diester. Additionally, PVI can incorporate the reactants on its domains by hydrophobic and electrostatic attraction, confrming the polymer multifunctionality. Moreover, a pronounced micellar catalysis was observed for the reactions which, surprisingly, occurs with both cationic and anionic micelles, due to favorable approximation effects. The micellar effects observed confrms the reactivity of the bipolar species. Based on the pseudophase model, the reagents can be incorporated in the micellar phase, mainly by hydrophobic forces. Overall, we confrm that PVI has great potential as an artificial enzyme, since it undergoes enzymatic-like mechanisms with an elegant bifunctional catalysis.