Metal-Ion-Induced Mechanical Chirality: Achiral Rotaxane as the Only Ligand in Chiral Palladium(II)-N-Heterocyclic Carbene Complexes

We report the insertion of Pd(II) into an originally achiral rotaxane producing two chiral metallorotaxanes: one is planar-chiral, with its two interlocked components both chelating nonequivalently to the metal center; the other is C-2-symmetricalchiral, with the dynamically exchangeable stereogenic units stabilized by the interlocked structure. Chiral additives confirmed the existence of chirality, with the enantiomers of the C-2-symmetrical N-heterocyclic carbene complex being resolved using chiral TRISPHAT counteranions.

Automated summary

This paper reports the insertion of Pd(II) into an initially achiral rotaxane, resulting in two chiral metallorotaxanes. Chiral additives and chiral TRISPHAT counteranions were used to confirm the existence of chirality and resolve the enantiomers of the C-2-symmetrical N-heterocyclic carbene complex.