Nickel-catalyzed reductive cross-coupling polymerization of dithiosulfonates and dibromides for the synthesis of polythioethers†

The incorporation of heteroatoms in polymeric structures may promote some physical or chemical properties of polymers. Polythioethers are widely used as functional materials and are of great importance in both academia and industry. In conventional synthetic strategies, thiols with unpleasant odor are typically used as the starting materials. Here, we disclose a novel thiolation polymerization using dithiosulfonate as a surrogate thiolation reagent, which was applied with aliphatic dibromide in a nickel catalyzed reductive cross-coupling polymerization for the synthesis of polythioethers. An array of polythioethers were prepared with well-defined structures and decent thermal properties. Moreover, the refractive index of these polythioethers could reach up to 1.72, indicating a potential application as optical materials. This work establishes a novel thiolation polymerization toward polythioethers and starts an avenue for their applications.