Stable and Highly Regioselective Anionic Polymerization of (Z)-1-Phenyl[3]dendralene

Abstract

The anionic polymerization of (Z)-1-phenyl­[3]­dendralene (1Z-P3D) in THF with potassium naphthalenide (K-Naph) as an initiator was investigated. At −78 °C, a polymer of predictable molecular weight and narrow molecular-weight distribution (M w/M n = 1.26) was obtained quantitively in 24 h. The active chain-end carbanion derived from 1Z-P3D was significantly stabilized by conjugation with a phenyl substituent at the C1 position of the monomer; side reactions such as nucleophilic addition to the double bond in other polymer main chains were not observed over a wide temperature range (−78–0 °C). The microstructure of the obtained poly­(1Z-P3D) contained a predominant amount of the 1,4 structure (>90%). Thus, the polymerizability of 1Z-P3D was different from that of previously reported 2-phenyl[3]­dendralene (P3D), in terms of the nucleophilicity of the active chain end and regioselectivity in the propagation reaction.