Catalyst- and Solvent-Free Click Synthesis of Cyclodextrin-Based Polyrotaxanes Exploiting a Nitrile <i>N</i>-Oxide

A catalyst- and solvent-free synthesis of cyclodextrin-based polyrotaxanes exploiting a stable nitrile <i>N</i>-oxide as an end-capping agent was achieved. The C–C bond-forming end-capping reaction of an allyl-terminated pseudopolyrotaxane with the nitrile <i>N</i>-oxide proceeded smoothly by solid-state grinding in a mortar to afford a polyrotaxane