Oxidative Polymer Degradation via Cope Elimination

We report on a mild and efficient method to degrade poly(β-amino esters) (PBAEs) and poly(amido amines) (PAMAMs) via Cope elimination. Oxidation of backbone tertiary amines to N-oxides allowed for the spontaneous abstraction of acidic β ester/amide protons, resulting in subsequent chain cleavage. We show that quantitative PBAE degradation can be achieved within 15 min in several organic solvents by treatment with meta-chloroperbenzoic acid. Despite being a more robust substrate than the PBAEs, PAMAMs could also be fully degraded within 18 h via an aqueous degradation protocol with hydrogen peroxide. Mass spectrometry revealed similar degradation profiles for PBAEs and PAMAMs with vinyl, divinyl, and dihydroxylamine compounds being the major degradation byproducts. Finally, we demonstrate that Cope elimination-induced degradation under mild conditions can be extended to network polymers.