Comprehensive Picture of Functionalized Vinyl Monomers in Chain-Walking Polymerization

Copolymerization of functionalized vinyl monomers with olefin is extraordinarily important to provide value-added polar polyolefins. A study on the reactivity of functionalized vinyl monomers enables the community to understand and then tune this reaction. In contrast to numerous reports on reactivity and copolymerization of a variety of functionalized vinyl monomers using benchmark phosphinesulfonato Pd­(II) catalysts, a coherent picture of a comprehensive range of functionalized vinyl monomers in milestone α-diimine Pd­(II)-mediated chain-walking polymerization is elusive. In this contribution, by use of a unique α-diimine Pd­(II) catalyst developed by us recently, we report a comprehensive investigation of an NMR scale on insertion, regiochemistry, and chain walking of a wide scope of functionalized vinyl monomers including fundamental polar vinyl monomers (acrylic acid, acrylates, N,N-isopropylacrylamide, diethyl vinyl phosphonate, vinyl acetate, etc.), polar allyl monomers (allyl acetate, t-butyl 3-butenoate, etc.), 1,1- and 1,2-disubstituted polar vinyl monomers (methyl methacrylate, 2-(trifluoromethyl)­acrylic acid, methyl crotonate, vinylene carbonate, etc.), and polar divinyl monomers (acrylic anhydride, allyl acrylate, allyl methacrylate, etc.). These insights gained further correlate to ethylene copolymerization in a pressure reactor. As a result, a family of highly branched polyethylene architectures with exclusive in-chain incorporation of functional groups or with a functional group incorporated into both the main chain and the end of branches concurrently or without a functional group is accessible.