Racemic Monomer‐Based One‐Handed Helical Polymer Recognizes Enantiomers through Auto‐Evolution of Its Helical Handedness Excess
Tomoyuki Ikai, Tomoyuki Kurake, Shogo Okuda, Katsuhiro Maeda, Eiji Yashima
Abstract
A racemic monomer-based optically inactive polyacetylene folds into a one-handed helix assisted by a nonracemic alcohol, which can separate various enantiomers as a chiral stationary phase in chromatography. The chiral-resolving power is virtually identical to that of the enantiopure monomer-based one-handed helical polyacetylene. Because of its unique static memory of the induced helicity, the original racemic polyacetylene expresses an auto-evolution of its helical handedness over time, and at the same time, chirality of the nonracemic alcohol is discriminated accompanied by successive enhancement of its optical purity enantioselectively adsorbed on the helical polyacetylene owing to the chiral filter effect as directly monitored by NMR, which contributes to further enhancing the helix-sense-excess of the helical polyacetylene.