Silacyclobutane-Mediated Re-Activation of “Sleeping” Polyvinylferrocene Macro-Anions: A Powerful Access to Novel Metalloblock Copolymers

Little advantage has been taken so far of the manifold promising options provided by the living anionic polymerization of vinylferrocene. The major reason is that the propagating polyvinylferrocene (PVFc) chains suffer loss of reactivity in the oligomeric state already, and even can change into a “sleeping” mode prior to complete monomer consumption. Formation of broadly distributed and/or constitutionally inhomogeneous products is the consequence. Here we report on the efficient reactivation of the deactivated or sleeping PVFc macro-anions by their simultaneous treatment with 1,1-dimethylsilacyclobutane and 1,1-diphenylethylene. We demonstrate the efficiency of this procedure by synthesizing PVFc-based diblock copolymers with poly(methyl methacrylate) and poly(2-vinylpyridine), respectively, using sequential monomer addition protocols.