ORS1-0200
Anionic Ring-Opening Polymerization of Oxindole Derivatives with a Cyclopropane Ring
Topic
S1. Polymer Synthesis
When and Where
Sep 29, 2026
16:15 - 16:30
Room 101
Session Chairs
Min Sang KWON
Presenter(s)
Chihiro Homma (Institute of Science Tokyo)
Co-Author(s)
Abstract
Cyclopropane compounds are three-membered ring hydrocarbons with significant ring strain energy arising from their highly distorted bond angles. When cyclopropane derivatives are employed as cyclic monomers, ring-opening polymerization can proceed via cleavage of carbon–carbon bonds. However, compared with epoxides and aziridines, which undergo facile anionic ring-opening polymerization through cleavage of carbon–oxygen or carbon–nitrogen bonds, only a limited number of examples have been reported for cyclopropane-based systems. The main difficulty lies in the high bond dissociation energy of carbon–carbon bonds and the insufficient stabilization of the resulting propagating carbanions. As a result, applicable monomers are largely restricted to those bearing electron-withdrawing groups at suitable positions. In this study, we designed novel cyclopropane monomers incorporating an oxindole framework with a spiro-cyclic structure. The acidic amide hydrogen of oxindole ring was substituted with methyl or hexyl group. The phenyl and amide groups in the oxindole ring are expected to stabilize the propagating carbanion, thereby facilitating anionic ring-opening polymerization. The polymerization successfully proceeded to afford the desired polymers with controlled molecular weights and narrow molecular weight distributions. These results demonstrate that rational monomer design can expand the scope of anionic ring-opening polymerization of cyclopropane derivatives.
