Synthesis of Novel Palladium Complexes Containing β‐Diketonate and NHC Ligands and their Catalytic Ability for Addition Polymerizations of the Functional Norbornenes

Palladium complexes containing various N‐heterocyclic carbene (NHC) ligands have been successfully synthesized by the reaction with various β‐diketonate complexes. Treatments of Pd(acac)2 with NHC salts such as 1,3‐di(2,6‐diisopropylphenyl)imidazolium chloride (IPr·HCl) or 1,3‐di(mesityl)imidazolium chloride (IMes·HCl) resulted in [Pd(acac)(NHC)Cl] complexes and these complexes were characterized by NMR. Moreover, these palladium complexes showed moderate to good catalytic activities towards addition polymerization of various functional norbornenes. The effects of various reaction parameters onto the catalytic activity towards polymerization of functional norbornenes have been thoroughly investigated. Addition polymerizations of the functional norbornenes by novel Pd complexes