Synthesis of polynorbornadienes by ring-opening metathesis polymerization and their saturated derivatives bearing various ester groups and carboxyl groups

Various symmetric and non-symmetric polynorbornadienes having a variety of ester groups and carboxyl groups were synthesized by ring-opening metathesis polymerization (ROMP) with Grubbs' third generation catalyst (G3 or [Ru]-III catalyst) in a controlled living manner from half-esters prepared by the selective monohydrolysis of symmetric diesters that we previously reported. The half-esters thus obtained can be directly submitted to ROMP with the G3 catalyst, leading to mostly the trans structure and narrow polydispersity indexes. The subsequent hydrogenation yielded saturated polymers, improving the thermostabilities according to the T5 d results. Our selective monohydrolysis reactions combined with ROMP initiated by the G3 catalyst have proven to be an efficient tool for the production of a variety of homopolymers with well-controlled structures in a living manner.

Automated summary

Various symmetric and non-symmetric polynorbornadienes with different ester and carboxyl groups were synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' third generation catalyst (G3 or [Ru]-III catalyst). Selective monohydrolysis of symmetric diesters prepared half-esters, which were then directly subjected to ROMP with G3 catalyst resulting in trans structure and narrow polydispersity indexes. Hydrogenation of the polymers produced saturated polymers, improving their thermostabilities. The combination of selective monohydrolysis reactions and ROMP with G3 catalysts is an efficient method for producing various well-controlled homopolymers in a living manner.