Selective Synthesis of Single‐Handed Helical Polymers from Achiral Monomer and a Mechanism Study on Helix‐Sense‐Selective Polymerization

Inspired by the exquisite helices in Nature, fabrication of helical materials with controlled handedness has attracted considerable attention. Herein, we report on precis synthesis of single left‐ and right‐handed helical polyisocyanides through living polymerization of achiral monomers using chiral palladium catalysts under helix‐sense‐selective manner. Mechanism study revealed that the yielded helices with opposite handedness showed different activity of the living chain end. The helix with unfavored handedness was self‐terminated, while the one with favored handedness showed high activity and could undergo chain propagation to form a high molecular weight polymer with maintained single‐handed helicity. Living polymerization of achiral isocyanide by chiral PdII‐catalyst yielded a mixture of right‐ and left‐handed helices with great bias. The helix with preferred handedness has an active chain end and can undergo chain propagation. While the opposite handed helix was self‐terminated due to the inactive chain end. The mechanism study will pave an avenue for the development of new catalysts for synthesis of chiral materials.