Alternating copolymerization of carbon monoxide and vinyl arenes using [N,N] bidentate palladium catalysts

The alternating copolymers of carbon monoxide (CO) and vinyl arene monomers, namely aromatic polyketones, are a family of attractive engineering plastic. In the catalytic synthesis of this kind of polymeric materials, [N,N] bidentate palladium catalysts represent the most successful catalytic systems. In this review, we introduce the present status of polyketone synthesis, with a focus on the aromatic polyketones made from vinyl arene and CO. We also address the palladium-catalyzed CO/vinyl arene alternating copolymerization mechanism. A variety of [N,N] bidentate palladium catalysts bearing 2,2 '-bipyridine, 1,10-phenanthroline, alpha-diimine, and pyridine-imine ligands are surveyed for CO/vinyl arene copolymerization. The effects of vinyl arene monomer, counteranion, and solvent on copolymerization are also discussed. The copolymerization stereochemistry including chain end-control and enantiomorphic site control mechanisms is introduced. This review aims to promote the design of [N,N] bidentate palladium catalysts for CO/vinyl arene copolymerization for the development of high-performance aromatic polyketones.