Diversity Oriented Preparation of Pillar[5]arene-Containing [2]Rotaxanes by a Stopper Exchange Strategy.

Invited for this month's cover are Iwona and Jean-François Nierengarten from the University of Strasbourg. The cover picture shows the structure of a [2]rotaxane building block bearing 3,5-bis(trifluoromethyl) benzenesulfonate (BTBS) stoppers. The BTBS moieties of this compound are good leaving groups allowing to perform stopper exchange by treatment with different nucleophiles to afford the corresponding rotaxanes with ester, ether or thioether stoppers. Read the full text of their Full Paper at https://doi.org/10.1002/open.202000035.