Stereodivergent Synthesis of Enantiopure Oligomers with Tailored Physical Properties

Stereochemistry can significantly affect the chemical and physical properties of synthetic polymers. Compared to the structural precision of natural biomacromolecules (e.g. proteins and nucleic acids) that are chiral and enantiopure, fully controlling the stereochemistry of synthetic polymers is considerably more challenging. However, the development of next generation polymer materials will require increasing levels of microstructural control and an in-depth understanding of structure-property relationships. Herein, we assemble an unprecedented library of enantiopure oligomers, specifically indene-maleimide-indene trimers, with identical primary structure but different stereochemistry through a novel highly stereoselective radical addition process. Full characterization of these unique trimers reveals that the structural rigidity and molecular compactness are responsible for their unique physical properties, including crystallization, glass transition temperature and optical activity. This strategy provides an innovative means to build oligomeric blocks for synthetic polymers and tailor their physical properties.