Controlled Polymerization of β-Pinadiene: Accessing Unusual Polymer Architectures with Biomass-Derived Monomers

Biomass-derived polymers are emerging as critically needed alternatives to their petrochemical counterparts. Terpenes, which are among the most abundant natural products, represent particularly fertile chemical space for monomer development (given their inherent structural complexity). Here, we present the living vinyl-addition polymerization of beta-pinadiene (the cumulated congener of beta-pinene) at room temperature. Employing [(pi-allyl)NiOCOCF3](2) as a catalyst afforded the desired polymers with good control over molecular weight and dispersity. Interestingly, the bicyclic pinane core was retained in the isolated materials (which starkly contrasts prototypical pinene polymerizations). Moreover, the reported materials exhibited impressive thermal stability (T-d = 294 degrees C) and high glass transition temperatures (T-g = 160 degrees C). As the polymerization of terpene-derived cumulenes can afford scaffolds that defy current synthetic logic, we anticipate our work will unlock additional avenues for sustainable polymer development.