Nicodemo R. Ciccia, John F. Hartwig
Abstract As plastic waste increases, it is urgent to create new, sustainable materials. Functional polyolefins represent a subset of materials with unique properties that could obviate the need for unrecyclable composites. However, the diversity of polymer structures, which dictate properties, is limited by copolymerization strategies. Post‐polymerization functionalization of polyolefins represents a powerful orthogonal strategy to create new materials rapidly, and metal‐catalyzed variants impart selectivities that create polymers with unique structures and potential applications. This review highlights central challenges, contributions, and opportunities for future development of reactions of polyolefins. Specifically, we provide a detailed analysis of the challenges and precedents for metal‐catalyzed functionalization of C─H and C═C bonds of polyolefins, including catalytic alkylation, oxidation, borylation, alumination, amination, and dehydrogenation of C─H bonds and catalytic hydrocarbonylation, hydroamination, hydroaminomethylation, dihydroxylation, and cross‐metathesis of C═C bonds. Finally, we discuss opportunities for further reaction development to aid and motivate the design of new transformations of polyolefins.