Regiodivergent Chain‐Growth Polymerization of Aza‐π‐Allylpalladium Zwitterions via Proton Transfer

Proton transfer is a fundamental process in many ring‐opening polymerization (ROP) strategies, imparting precise control over polymer chain growth under mild conditions. Merging proton transfer mechanism with versatile reactive intermediates—such as organometallic species—presents exciting opportunities to unlock new chemical space for polymer synthesis. Here, we report a mild palladium‐catalyzed ROP of N ‐sulfonyl vinyl aziridines via a π‐allyl‐Pd II ‐N − zwitterionic intermediate. This polymerization features unique initiation and propagation proceeding through 1) proton transfer from a diversity of protic X─H/C─H bonds, and 2) subsequent ligand‐controlled regiodivergent allylic amination reaction. This approach enables the synthesis of a range of nitrogen‐containing homo‐ and copolymers, surpassing traditional base‐promoted polymerization methods by expanding the amine spacing and enhancing functional group tolerance.