Hypervalent Iodine Based Reversible Covalent Bond in Rotaxane Synthesis

Angew Chem Int Ed Engl. 2019 Dec 9;58(50):18182-18185. doi: 10.1002/anie.201908953. Epub 2019 Oct 30.

Abstract

Reversible covalent bonds play a significant role in achieving the high-yielding synthesis of mechanically interlocked molecules. Still, only a handful of such bonds have been successfully employed in synthetic procedures. Herein, we introduce a novel approach for the fast and simple preparation of interlocked molecules, combining the dynamic bond character of bis(acyloxy)iodate(I) anions with macrocyclic bambusuril anion receptors. The proof of principle was demonstrated on rotaxane synthesis, with near-quantitative yields observed in both the classical and "in situ" approach. The rotaxane formation was confirmed in the solid-state and solution by the X-ray and NMR studies. Our novel approach could be utilized in the fields of dynamic combinatorial chemistry, supramolecular polymers, or molecular machines, as well inspire further research on molecules that exhibit dynamic behavior, but owing to their high reactivity, have not been considered as constituents of more elaborate supramolecular structures.

Keywords: anion receptors; bambusurils; dynamic covalent bonds; macrocycles; rotaxanes.