Anionic Polymerization of Chiral Isocyanate and Influence of the Initiator on Changes in the Optical Activity

Abstract

A chiral polyisocyanate, poly[6-{1-[(S)-(–)-2-methylbutyl]oxycarbonylamino}hexyl isocyanate], was synthesized using sodium diphenylmethanide and sodium naphthalenide as unidirectional and bidirectional initiators, respectively, via anionic polymerization in THF at –98°C. NaBPh4 as a common ion salt was used to produce the polymer in quantitative yield and with narrow molecular-weight distribution. The polymer showed different optical activity depending on the nature of the initiator.