Interfacial Ring-Opening Polymerization of Amino-Acid-Derived <i>N</i>‑Thiocarboxyanhydrides Toward Well-Defined Polypeptides

Interfacial ring-opening polymerizations (iROP) of α-amino-acid derived N-thiocarboxyanhydrides (NTAs) in hexanes or heptane suspension using soluble primary amine initiators have been demonstrated to produce polypeptides with controlled molecular weight and low-to-moderate molecular weight distribution under mild conditions. The NTA monomers were shown to have significantly enhanced moisture and thermal stability relative to N-carboxyanhydrides (NCAs), resulting in long shelf life and allowing the polymerization to occur quantitatively in open air.