Vinylogous Anionic Ring-Opening Polymerization of Vinylidenecyclopropanes with Native C–H Bonds as the Dormant Species

Since its inception in 2023, the concept of “C–H bonds as the dormant species” to control chain growth has emerged as a promising, though still evolving, strategy for precision polymer synthesis. Beyond offering a simpler polymerization method, this concept is expected to promote unprecedented reaction pathways. In this study, we report the first vinylogous anionic ring-opening polymerization (ROP) of vinylidenecyclopropanes. Cooperative La(OTf)₃/DBU catalysis, in conjunction with various sp³ and sp² C–H bonds, has streamlined the synthesis of well-defined alkyne polymers, which are amenable to further chemical modifications. Control experiments and density functional theory (DFT) calculations provide insights into the origin of selectivity and the role of dormant C–H bonds in the reversible-deactivation equilibrium.