A reflection on 'Bimetallic mechanism operating in the copolymerization of propylene oxide with carbon dioxide catalyzed by cobalt-salen complexes'.

The development of catalysts that exploits cooperative interactions between two distinct metal centers has emerged as a powerful strategy in modern organic transformations. In 2010, we reported dinuclear cobalt complexes for the alternating copolymerization of epoxides with carbon dioxide, in which an intramolecular bimetallic propagation mechanism operates to afford high catalytic activity (K. Nakano, S. Hashimoto, and K. Nozaki, Chem. Sci. 2010, 1, 369-373, https://doi.org/10.1039/C0SC00220H). In this reflection, we provide a brief overview of subsequent studies on cooperative bimetallic catalysts for the epoxide/CO2 copolymerization.