Activated Monomer Polymerization of an N-Sulfonylazetidine

Previously, N-(methanesulfonyl)azetidine (MsAzet) was found to polymerize anionically via ring-opening at temperatures >100 °C to form p(MsAzet) in the presence of an anionic initiator. In the current report, potassium(azetidin-1-ylsulfonyl) methanide (KMsAzet), formed from deprotonation of the methanesulfonyl group of MsAzet by KHMDS, is shown to undergo spontaneous AROP at room temperature to form p(N-K-MsAzet). The structure of p(N-K-MsAzet) differs from that of p(MsAzet), as the sulfonyl groups are incorporated into the polymer backbone of p(N-K-MsAzet). Reaction of p(N-K-MsAzet) with MeOH produces p(N-H-MsAzet), a semicrystalline polymer with a structure like that of polyamides, but with sulfonylamides in place of the carboxamides found in polyamides. Reaction of p(N-K-MsAzet) with benzyl bromide results in the formation of amorphous p(N-Bn-MsAzet). P(N-K-MsAzet) is hypothesized to form via an activated monomer anionic polymerization; this is supported by polymerization kinetic data and structural characterization of the resulting polymers.