Living Anionic Polymerization of 1‐Adamantyl 4‐vinylphenyl ketone

The anionic polymerization of 1‐adamantyl 4‐vinylphenyl ketone (1), a styrene derivative carrying an electrophilic carbonyl group, is carried out in tetrahydrofuran (THF). Although no polymerization of 1 occurs with sec‐BuLi at −78 °C for 48 h, a polymeric product of 1 is obtained with diphenylmethyllithium in 10% yield under similar conditions. The resulting poly(1) has a very broad molar‐mass dispersity (Đ M = M w/M n = 1.72) and a molecular weight higher than the calculated value based on the molar ratio of the monomer and initiator and the conversion. On the other hand, the polymerization of 1 with diphenylmethylpotassium or diphenylmethylcesium quantitatively proceeds in THF at −78 °C within 48 h to form the polymers with predicted molecular weights and narrow molecular weight distributions (M w/M n < 1.1). The stability of the propagating carbanion derived from 1 is demonstrated by the quantitative efficiency of the postpolymerization (sequential monomer addition). The reaction of the adamantyl ketone moieties of poly(1) with methylmagnesium iodide quantitatively proceeds in THF/diethyl ether at room temperature, indicating the high electrophilicity of ketone groups. The resulting poly(1) has a high glass transition temperature at 193 °C, indicating the effect of the bulky adamantyl substituent. The anionic polymerization of 1‐adamantyl 4‐vinylphenyl ketone (1) quantitatively proceeds in THF at −78 °C using diphenylmethylpotassium, diphenylmethylcesium, or triphenylmethylpotassium as an initiator to give the polymers with predicted molecular weights and narrow molecular weight distributions. The resulting poly(1) has an electrophilic acyl group and a high glass transition temperature at 193 °C.