Synthesis of Pyrrole‐Based Poly(arylenevinylene)s via Co‐Catalyzed Hydroarylation of Alkynes.

Polyaddition via the Co‐catalyzed hydroarylation of 1‐(2‐pyrimidinyl)pyrrole with aromatic diynes affords poly(arylenevinylene)s under mild conditions. This reaction avoids production of stoichiometric amounts of by‐products. Although structural analysis of the obtained polymers reveals the presence of 1,1‐vinylidene unit, switching the counter anion of the Co catalyst and steric hindrance of the diyne monomers improves the regioselectivity of the polymers. When a catalyst with bulky counter anions is used for the reaction of less hindered diyne monomers, 1,2‐vinylene linkages are formed dominantly over 1,1‐vinylidene linkages (93:7). The effect of the regioselectivity of the polymer on the optical and semiconducting properties is also evaluated. [ABSTRACT FROM AUTHOR]