Inverted metal-free active tem... Note

Inverted metal-free active template synthesis of rotaxanes via axle‑mediated macrocyclization

Rotaxane assembly by active template synthesis has so far relied on specialized rings to trap the threaded axle. Now it has been shown that oligo(ethylene glycol) chains can accelerate ester aminolysis macrocyclization around themselves, producing [2]rotaxanes without requiring template sites within the ring. Iteration of this process efficiently yields higher-order rotaxanes.