Development of Synthetic Method for π-Conjugated Polymers via Direct Arylation Polycondensation

: Recent progress in direct arylation polycondensation made by our group is summarized herein. Poly- condensation via direct arylation of C ─ H bonds in fluorinated benzenes or thiophene analogs afforded the corresponding conjugated polymers with high molecular weight in good yield. These protocols enable synthesis of conjugated polymers without prior preparation of organometallic monomers. Optimization of the reaction conditions led to the establishment of a simple catalytic system employing reduced Pd catalyst loading in the absence of a phosphine ligand. Elemental analysis and microanalysis revealed the high purity of the obtained polymer, which is derived from the simple catalytic system. The pure polymer exhibited excellent performance as a material for organic field effect transistors and organic photovoltaics.