Planarchiral rotaxanes were synthesized from crown ether and secondary ammonium salt via trialkylphosphane-catalyzed acylative end-capping. Their opticalresolution was achieved by chiral HPLC after acylative neutralization of the ammonium group. When optically active trialkylphosphane 2 was used as the chiral acylation catalyst, optically active rotaxane (4.4% ee) was obtained.
Mechanically chiral compounds are utilized as a chiral source. Polyacetylenes with optically active mechanically chiral rotaxanes in the side chains show strong circular dichroism on the main-chain absorption regions, indicating that the rotaxanes efficiently induce helicity with preferred handedness. These results demonstrate the significance and utility of mechanically chiral rotaxanes for the construction