Activated Polyacrylamides as Versatile Substrates for Postpolymerization Modification.

Abstract

The displacement of an activated leaving group in polymeric repeat units is a powerful method of postpolymerization modification. This strategy enables the synthesis of polymers otherwise unobtainable by direct polymerization as well as the preparation of a diverse array of macromolecular structures. We demonstrate that the activation of acrylamide through the introduction of two tert-butyloxycarbamate (Boc) groups followed by radical polymerization leads to a new class of activated polyacrylamides analogous to well-known activated polyacrylates. Transamidation of poly(di(Boc)-acrylamide) utilizing primary amines proceeds to high conversion under mild conditions, and the products can be readily purified. Less nucleophilic secondary amines and alcohols require more forcing conditions. We demonstrate the utility of this approach by preparing copolymers capable of on-demand gel formation and the synthesis of block polymers using controlled radical polymerization.