N‑Containing 1,7-Octadiyne Derivatives for Living Cyclopolymerization Using Grubbs Catalysts

Synthesis of a new class of conjugated polyenes containing N-heterocyclic six-membered rings was demonstrated via cyclopolymerization of N-containing 1,7-octadiyne derivatives using Grubbs catalysts. Successful cyclopolymerization was achieved by introducing protecting groups to the amines in the monomers. Moreover, a hydrazide-type monomer containing a di-<i>tert</i>-butyloxycarbonyl group (<b>6</b>) promoted the living cyclopolymerization to give poly­(<b>6</b>) with a controlled molecular weight and narrow dispersity. This living polymerization allowed us to prepare various conjugated diblock copolymers using poly­(<b>6</b>) as the first block