We have newly designed an original bifunctional monomer (PAVE) containing both a phenylacetylene (PA) group and a vinyl ether (VE) group, which is expected to be a key material for the synthesis of brush-shaped polymers consisting of a poly(phenylacetylene) (polyPA) main chain and polyVE side chains. Actually, we have demonstrated the selective chemical transformation of the VE moiety of PAVE to an initiator site for the living cationic polymerization of isobutyl vinyl ether (IBVE), and then succeeded in the controlled synthesis of a novel PA-end-capped polyIBVE macromonomer. Moreover, using this macromonomer, the first synthesis of a brushshaped polyPA bearing polyVE side chains was achieved via Rh complex-mediated homopolymerization. (C) 2014 Wiley Periodicals, Inc.