Functional polythioamides derived from thiocarbonyl fluoride

Polythioamide is a unique type of sulfur-containing polymers with advanced functionalities. However, current synthetic approaches based on elemental sulfur, which could easily react with unsaturated functional groups, restrict the choice of substrates. Inspired by the highly efficient sulfur-fluoride exchange (SuFEx) polymerization through discrete hubs, we here report a novel and general method for the synthesis of polythioamides from diboronic acids, secondary diamines, and thiocarbonyl fluoride as the connective hub. Well-defined structures, including previously inaccessible unsaturated substrates, were realized. The polythioamides can efficiently and selectively bind to metal ions and were applied in precious metal recovery. Further development results in PdII-crosslinked single-chain nanoparticles acting as a recyclable homogeneous catalyst, demonstrating promising applications of these unprecedented polythioamides. We anticipate that thiocarbonyl fluoride could be a powerful hub for the challenging synthesis of sulfur-containing polymers.