Helix-Sense-Selective Polymerization of Achiral Bis(hydroxymethyl)phenylacetylenes Bearing Alkyl Groups of Different Lengths

4-Alkyloxy-3,5-bis(hydroxymethyl)phenylacetylenes with eight types of alkyl groups were synthesized and polymerized with a chiral catalytic system. We found that the length of the alkyl groups played a very important role in achieving helix-sense-selective polymerization. Five helix-sense-selective polymerizations were achieved resulting in polymers with alkyl groups whose chain length was longer than six. We think that the longer-chain alkyl groups prevented the polymers from becoming insoluble by forming intermolecular hydrogen bonds between the hydroxyl groups, and stabilized their one-handed helical structure by promoting the formation of intramolecular hydrogen bonds.