A chiral macrocycle for the stereoselective synthesis of mechanically planar chiral rotaxanes and catenanes
Shu Zhang, Arnau Rodríguez-Rubio, Abed Saady, Graham J. Tizzard, Stephen M. Goldup
Abstract
<h2>Summary</h2> Active template auxiliary methodologies have previously been developed for the stereoselective synthesis of chiral interlocked molecules in which the mechanical bond provides the sole stereogenic unit. To date, however, the covalent auxiliary has been included in the half-axle components (rotaxanes) or pre-macrocycle components (catenanes), and thus mechanically chiral rotaxane and catenane syntheses rely on different chiral components. Here, we present a single, simple amino-acid-derived macrocycle that mediates the formation of both catenanes and rotaxanes in excellent stereoselectivity. We demonstrate the flexibility of our approach through the stereoselective synthesis of all three isomers of a co-conformationally mechanically planar chiral [3]rotaxane.