Rapid Access to 2,2'-Bithiazole-Based Copolymers via Sequential Palladium-Catalyzed C-H/C-X and C-H/C-H Coupling Reactions.

A rapid access to 2,2'-bithiazole-based copolymers has been developed on the basis of the sequential palladium-catalyzed CH/CX and CH/CH coupling reactions. To assemble a "copolymer" through homopolymerization, a type of symmetric A-B-A-type building block is designed as the monomer and prepared via the regioselective C5H arylation of thiazole. A PdCl2 /CuCl-cocatalyzed oxidative CH/CH homopolymerization has been established to afford the 2,2'-bithiazole-based copolymers with high Mn (up to 69400). The current protocol features atom- and step-economy and exhibits a potential in the highly efficient construction of conjugated copolymers.