A Dense-Shell Macromolecular Scaffold for Catalyst or Substrate Guided Catalysis in Cellular Environment

Placing metal complexes in macromolecular scaffolds has shown its usefulness in improving catalytic activity for synthetic purposes and reactions in biological environments. Here we show that a star polymer scaffold with a dense shell and a concentrated ligand core can be readily synthesized from an integrated polymerization-crosslinking process mediated directly by a tris-triazole ligand. The straightforward synthesis can give well-defined polymeric nanoparticles with a core-shell structure, with dense polymeric shell protecting the ligands in the core that are readily available for metal coordination. Using copper and palladium catalyst as examples, we show that those macromolecular Cu and Pd catalysts can mediate aqueous “Click” reactions and propargyl carbamate deprotection, respectively. The scaffolds not only grant protection and stabilization of the catalytic centers, but more importantly, they can be tuned to promote reactions in different cellular locations in mammalian cells, and the localizatio...