AB-Versus AA+BB-Suzuki polycondensation: A palladium/Tris(tert‐butyl)phosphine catalyst can outperform conventional catalysts

A Pd/Pt‐Bu3 catalyst having bulky, electron‐rich ligands significantly outperforms conventional “step‐growth catalysts” Pd(PPh3)4 and Pd(Po‐Tol3)3 in the Suzuki polycondensation of the AB‐type arylene‐based monomers, such as some of the substituted fluorenes, carbazoles, and phenylenes. In the AA+BB polycondensation, Pd/Pt‐Bu3 also performs better under homogeneous reaction conditions, in combination with the organic base Et4NOH. The superior performance of Pd/Pt‐Bu3 is discussed in terms of its higher reactivity in the oxidative addition step and inherent advantages of the intramolecular catalyst transfer, which is a key step joining catalytic cycles of the AB‐polycondensation. These findings are applied to the synthesis of a carbazole‐based copolymer designed for the use as a hole conductor in solution‐processed organic light‐emitting diodes