Catalytic Asymmetric Synthesis and Optical Resolution of Planar Chiral Rotaxane

Planar chiral rotaxanes were synthesized from crown ether and secondary ammonium salt via trialkylphosphane-catalyzed acylative end-capping. Their optical resolution 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.