Living (co)polymerization of ethylene and bio-based furfuryl acrylate using dibenzobarrelene derived α-diimine palladium catalysts†
Catalyzed copolymerization of petroleum-based ethylene and bio-based polar monomers is of significant interest because of their renewable character and functionalization. In this study, we reported a series of dibenzobarrelene-derived α-diimine palladium complexes for the (co)polymerization of ethylene and bio-based furfuryl acrylate (FA). The differences of ethylene polymerization between the in situ activation of the neutral chloromethylpalladium complex and the well-defined cationic palladium catalyst were initially studied. Increasing the steric bulk on the ligand backbone enhanced the tolerance of palladium catalysts toward the polar monomer. Living (co)polymerizations of ethylene and furfuryl acrylate were realized using dibenzobarrelene-derived α-diimine palladium catalysts. A mechanistic study showed that furfuryl acrylate is inserted into a Pd–Me bond in a 2,1-mode without interactions between the furyl ring and the palladium center, and then the primary product is rearranged into a six-membered chelate palladium by rapid isomerization.