Open-vessel Synthesis of Poly-N-methoxyethylglycine

Polypeptoids are widely used in biological applications owing to their diverse functions and proteolytic stability.One type of polypeptoids,poly-N-methoxyethylglycine(P-Nmeg),has been found to possess remarkable hydrophilicity and notable properties in terms of protein,cell,and bacterial antifouling.However,the currently known synthesis methods of P-Nmeg include solid-phase synthesis,which is time-consuming and difficult to scale up,and N-substituted N-carboxyanhydride(NNCA)ring-opening polymerization,whose monomers were difficult to store.In this study,we used the chemical stable Nmeg N-phenoxycarbonyl(NPC)as the monomer,which was obtained without the use of highly toxic reactants,such as phosgene or phosphorus halide,to synthesize P-Nmeg under open-vessel conditions.By adding BnNH_(2) as an initiator at 80℃,we can obtain controllable short chain length P-Nmeg with narrow dispersity.

Sulfanion-initiated open-vessel anionic ring-opening polymerization of N-sulfonyl aziridines

Anionic ring-opening polymerization(AROP)of N-sulfonyl aziridines is an important synthetic route to linear polyethyleneimine(PEI)and its derivatives.In most cases,inert atmosphere and dry solvent were needed because of the oxygen-and water-sensitive initiators/catalysts used.Therefore,the AROP of N-sulfonyl aziridines that can be entirely operated in air atmosphere is still a challenging task.Herein,we report a series of sulfanions,including xanthates,dithiocarbamates,dithiobenzoates,thioacetates,and thiolates,as the initiators for the AROP of N-sulfonyl aziridines.Due to their good stability,openvessel polymerization was achieved with high livingness,affording a range of well-definedα-,ω-telechelic poly(N-sulfonyl aziridine)homopolymers and block copolymers with narrow dispersities and tunable molecular weights.Theα-end group of these polyaziridines was readily converted to thiol group,which enabled further post-polymerization functionalization with benzyl acrylate and poly(ethylene glycol)via thiol-ene click chemistry.The establishment of open-vessel sulfanion-initiated AROP of N-sulfonyl aziridines thus lays a solid foundation for the bulk preparation and application of poly(N-sulfonyl aziridine)s and PEI derivatives.