Anionic Polymerization of N-Phenylitaconimide

N-Phenylitaconimide (N-PII) can be readily polymerized with basic initiators that involve carbide, nitride, and oxide anions such as sec-butyllithium, lithium diethylamide, and alkali metal tert-butoxide. Poly(N-PII) was obtained in 84, 73, and 78% yields with sec-butyllithium, lithium diethylamide, and lithium tert-butoxide, respectively, in THF at 0 °C for 3 h polymerization. The effect of countercation size on the anionic polymerization rate of N-PII (1,1-disubstituted ethylene type monomer with cyclic imide structure) with alkali metal tert-butoxides is inverse to that of N-phenylmaleimide (N-PMI) (1,2-disubstituted ethylene type one); i.e., it was observed that the polymerization rate increased as the ion radius of a countercation decreased. NMR spectroscopic data and molecular orbital calculations suggest that the anionic polymerization of N-PII took place only at the vinylidene group and no appreciable side reaction would occur. In the case of using the initiators with Li+ as a countercation, the m...