Two Modes of Asymmetric Polymerization of Phenylacetylene Having a L-Valinol Residue and Two Hydroxy Groups

A novel chiral phenylacetylene having a L-valinol residue and two hydroxymethyl groups was investigated for obtaining a chiral polymer from an achiral substituted acetylene monomer using a chiral catalytic system. Poly (VDHPA)s were purified by precipitation of THF solution into a large amount of acetone, and poly (V-PA)s were precipitated in toluene and then dried in vacuum to give red polymers. The role of two hydroxy groups was confirmed, the corresponding monomer VPA, which has the same substituent as monomer VDHPA, except for the absence of two hydroxy groups, was also synthesized and polymerized. The VDHPA was found to give one-handed helical polymers by both the helix sense selective polymerization and the asymmetric-induced polymerization. The monomer was suitable for both the helix sensitive polymerization with an chiral catalytic system and the asymmetric-induced polymerization with an achiral catalyst.