Radical Cascade Polymerization Involving Dual Cyano Group Migration to Synthesize Periodic Polymers

In radical polymerization, significant efforts have been devoted to synthesizing polymers with a unique main chain structure from presequenced cyclic monomers via ring-opening polymerization or presequenced linear α-olefins via step-growth polyaddition. Herein, we demonstrate the synthesis of polythioethers with tunable monomer sequences derived from linear α-olefin monomers via radical chain-growth polymerization. This development was enabled by highly efficient dual cyano migration-involved radical cascade polymerization. Furthermore, this strategy can be extended to other poly(thioether)s by incorporating an additional cyclization step into the radical cascade polymerization. This work offers a promising addition to the synthetic toolbox for accessing polymers with unprecedented structure.