A Metal‐Free “Threading‐Followed‐by‐Shrinking” Protocol for Rotaxane Synthesis

Abstract

Shrinking ring size: Synthesis of a [2]rotaxane has employed photoextrusion of SO2 from the arylmethyl sulfone motif of a [2]pseudorotaxane. A dumbbell-shaped guest molecule allows a shrinking reaction to decrease the number of atoms in the ring skeleton of the macrocyclic component of the [2]pseudorotaxane (see picture).