Efficient Copolymerization of Ethylene with Polar Divinyl Monomer by Phosphino‐Phenolate Nickel Catalyst

Comprehensive Summary Direct copolymerization of olefin with polar monomers via a coordination‐insertion mechanism appears as the most efficient and attractive method to prepare functionalized polyolefins. Herein, we carried out direct copolymerization of ethylene and allyl acrylate by a bulky phosphino‐phenolate nickel catalyst, in which high‐molecular‐weight copolymers bearing polar five‐membered and six‐membered ring structures were afforded. Comprehensive NMR and FT‐IR analyses revealed multiplex structure of the obtained copolymers, in which both the noncyclic structural units bearing pendant allyl moiety (A) as well as acrylate moiety (B) and the cyclic structural units, γ‐butyrolactones (C) and δ‐valerolactone (D) were found. Exhilaratingly, the content of different structural units of the produced copolymer could be tuned by adjusting the concentration of the comonomer. Moreover, we also proved that the nickel‐based catalyst could produce related copolymers with significantly enhanced copolymer molecular weights in the copolymerization of allyl acrylate and ethylene compared with the palladium‐based catalyst under the same conditions. The direct coordination copolymerization of ethylene and a polar divinyl monomer, allyl acrylate, was achieved by a bulky phosphino‐phenolate nickel catalyst, in which random copolymers with high molecular weight copolymers (Mw > 104) were obtained. The resultant ethylene/allyl acrylate copolymers were revealed to possess novel microstructures with both pendant double bond and five‐ and six‐membered cyclic structures.