Poly(<i>N</i>-acyliminophosphoranes): main chain functionalized poly(ylides) with pH-dependent degradation

Zwitterionic polymers have gained attention for various applications but are typically based on non-degradable polyolefin backbones. Here, we introduce an Fe(II)-catalyzed step-growth polymerization that enables <i>N</i>-acyliminophosphorane formation, incorporating ylides directly into the polymer main chain. This design imparts pH-responsive degradability in aqueous environments, and opens opportunities for stimuli-responsive polymer systems.