Ruthenium-catalyzed diazoacetate/cyclooctene metathesis copolymerization

As a powerful synthetic tool, ruthenium-catalyzed ring-opening metathesis polymerization (ROMP) has been widely used to prepare diverse polymers. In this paper, we demonstrated the polymerization of cyclooctene in the presence of diazoacetate or (bis)diazoacetate compounds. For the copolymerization of cyclooctene and diazoacetate, well-defined telechelic polymers bearing -COOEt, -COOBn or -TMS groups were presented along with efficient tuning of the polymer molecular weight. When using (bis)diazoacetate compounds, various random functionalized copolymers were produced with different functional groups and incorporation ratios (up to 11%). With a NaBArF cocatalyst, the conversion of diazoacetates or (bis)diazoacetates was significantly promoted, and the mechanism was also explored during the polymerization. After hydrogenation, polar functionalized high-density polyethylene was accessed which exhibited good properties because of the introduction of ester groups in the main chain.