On the basis of the Ru-catalyzed regiospecific direct double arylation of benzene rings possessing 3-methylpyridin-2-yl substituents to produce 1-aryl-2-(3-methylpyridin-2-yl)benzene derivatives, the synthesis of poly(p-phenylene) derivatives having 2,5-bis(3-methylpyridin-2-yl) substituents is described. The reaction of 1,4-bis(3-methylpyridin-2-yl)benzene with bromobenzene (2 equiv) was carried out in the presence of [RuCl2(eta(6)-C6H6)](2) (5 mol %) in 1-methyl-2-pyrrolidone at 120 degrees C for 24 h to produce 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene in 99% yield as a sole product. Neither 2,6-diphenylated nor further phenylated products was produced under the examined conditions. This regiospecific double arylation process was then applied to the synthesis of pi-conjugated polymers by use of aryl dibromides such as 1,4-dibromobenzene, 2,7-dibromo-9,9-dihexylfluorene, and 2,5-dibromothiophene. For example, a polymer was obtained in 73% yield by using 1,4-dibromobenzene, whose M-n and M-w/M-n were estimated to be 3300 and 1.51, respectively. The bathochromic shift of the ultraviolet (UV)-visible absorption spectrum with respect to that of the model compound, 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene, indicated the extension of the pi-conjugation. The blue fluorescence was also observed for the polymer upon the UV irradiation. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2771-2777