Controllable Polymerization of N-Substituted β-Alanine N-Thiocarboxyanhydrides for Convenient Synthesis of Functional Poly(β-peptoid)s

Poly(β-peptoid)is a class of polypeptide mimics that possesses excellent biocompatibility and resistance to proteolysis.However,the synthesis of poly(β-peptoid)s with functionalities is a long-standing challenge that greatly hinders the functional study and application of poly(β-peptoid)s.We report a controllable and easy synthesis of poly(β-peptoid)s bearing diverse func-tionalities via the ring-opening polymerization on N-substituted β-alanine N-thiocarboxyanhydrides(β-NNTAs).The polymerization can be carried out in open vessels under mild conditions using amines as the initiators to provide poly(β-peptoid)s with targeted molecular weights,narrow dispersities,and diverse functionalities in the side chains and termini.Theβ-NNTAs polymerization is even compatible with initiators bearing unprotected hydroxyl groups.The amphiphilic/cationic poly(β-peptoid)s exhibit a broad spectrum and potent antibacterial activities against multidrug-resistant bacteria.In addition,the highly favored stability of β-NNTA monomers for purification and storage highlights the advantages of this β-NNTA polymerization strategy for poly(β-peptoid)s synthe-sis,functional study,and application as a synthetic mimic of polypeptides.