Synthesis of One-Handed Helical Block Copoly(substituted acetylene)s Consisting of Dynamic <i>cis-transoidal</i> and Static <i>cis-cisoidal</i> Block: Chiral Teleinduction in Helix-Sense-Selective Polymerization Using a Chiral Living Polymer as an Initiator

By using a living one-handed helical <i>cis-transoidal</i> poly­(chiral substituted phenylacetylene) as a polymer initiator (poly­(<b>1</b>_n)), helix-sense-selective polymerization (<b>HSSP</b>) of an achiral phenylacetylene <b>2</b> having two hydroxy groups successfully afforded a diblock copoly­(phenylacetylene) (copoly­(<b>1</b>_n/<b>2</b>_m)) consisting of a dynamic one-handed helical <i>cis-transoidal</i> block and a static one-handed helical <i>cis-cisoidal</i> block. The formation of the diblock structure was confirmed by consumption of the chiral initiator, appearance of characteristic CD indicating the one-handed helical <i>cis-cisoidal</i> block, and occurrence of the selective photocylic aromatization reaction in the <i>cis-cisoidal</i> block. Therefore, <b>HSSP</b> has been achieved by using the chiral alkenyl groups in the initiator as a chiral source for the first time. In addition, since the <b>HSSP</b> was achieved in spite of the long distance between the chiral initiation site and the propagating site, chiral teleinduction through the rigid and static one-handed helical <i>cis</i>-cisoidal block based on domino effects was confirmed