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.