Construction of Axially Chiral Polymers by Asymmetric C-H Activation Polymerization

Chiral polymers hold great potential in biomimics and synthetic materials, owing to their unique properties associated with diverse forms of chirality. Although polymers with central chirality are well-developed, axially chiral polymers remain underexplored, presumably due to the lack of efficient synthetic methods. Herein, we develop a new strategy of asymmetric C-H activation polymerization for constructing axially chiral side chain polymers from prochiral monomers. Based on sequential Co-catalyzed C-H activation/annulation, the polymerization proceeds in a quantitative manner, affording a range of axially chiral side chain polymers with high molecular weights, diverse chemical structures and tunable chiroptical properties. Furthermore, by stereochemical analysis of carefully designed model reactions, we have unambiguously confirmed excellent atroposelectivity control over the polymerization. This efficient strategy, which represents a significant advance in polymer synthesis, could open up new avenues for the design of chiral polymer materials with desirable properties.