Direct and Tandem Routes for the Copolymerization of Ethylene with Polar Functionalized Internal Olefins.

Transition metal catalyzed ethylene copolymerization with polar monomers is a highly challenging reaction. After decades of research, the scope of suitable comonomer substrates has expanded from special to fundamental polar monomers and, recently, to 1,1-disubstituted ethylenes. Described in this contribution is a direct and tandem strategy to realize ethylene copolymerization with various 1,2-disubstituted ethylenes. The direct route is sensitive to sterics of both the comonomers and the catalyst. In the tandem route, ruthenium-catalyzed ethenolysis can convert 1,2-disubstituted ethylenes into terminal olefins, which can be subsequently copolymerized with ethylene to afford polar functionalized polyolefins. The one-pot, two-step tandem route is highly versatile and efficient in dealing with challenging substrates. This work is a step forward in terms of expanding the substrate scope for transition metal catalyzed ethylene copolymerization with polar-functionalized comonomers.