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

Hsien-Liang Cho; Chien-Chen Lai; Yi-Hung Liu; Hsiu-Fu Hsu; Shie-Ming Peng; Sheng-Hsien Chiu

doi:10.1021/acs.orglett.2c00426

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

Org Lett. 2022 Mar 18;24(10):1996-2001. doi: 10.1021/acs.orglett.2c00426. Epub 2022 Mar 7.

Authors

Hsien-Liang Cho¹, Chien-Chen Lai², Yi-Hung Liu¹, Hsiu-Fu Hsu³, Shie-Ming Peng¹, Sheng-Hsien Chiu¹

Affiliations

¹ Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
² Institute of Molecular Biology, National Chung Hsing University, 145 Xingda Road, South District, Taichung 402, Taiwan.
³ Department of Chemistry, Tamkang University, No.151, Yingzhuan Road, Tamsui District, New Taipei City 251301, Taiwan.

PMID: 35254087
DOI: 10.1021/acs.orglett.2c00426

Abstract

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 C₂-symmetrical-chiral, with the dynamically exchangeable stereogenic units stabilized by the interlocked structure. Chiral additives confirmed the existence of chirality, with the enantiomers of the C₂-symmetrical N-heterocyclic carbene complex being resolved using chiral TRISPHAT counteranions.