An auxiliary approach for the stereoselective synthesis of topologically Chiral catenanes

Abstract

Catenanes, molecules in which two rings are threaded through one another like links in a chain, can form as two structures related as object and mirror image but otherwise identical if the individual rings lack bilateral symmetry. These structuresare described as “topologically chiral” as, unlike most chiral molecules,it is not possible to convert onemirror-image formto the other undertherules of mathematical topology. Although intriguing, and discussed as early as 1961, to date all methods to access molecules containing only this topological stereogenic element requiretheseparation ofthe mirror imageforms using chiral stationary phase high performance liquid chromatography (PCSP-HPLC)which has limited their investigation to date. Here we present a simple method that uses a readily available source of chiral information to allow the stereoselective synthesis of topologically chiral catenanes.