Tying a Molecular Overhand Knot of Single Handedness and Asymmetric Catalysis with the Corresponding Pseudo-D3- Symmetric Trefoil Knot

Research output: Contribution to journalArticle

  • External authors:
  • Guzman Gil-Ramírez
  • Steven Hoekman
  • Matthew O. Kitching
  • Inigo Vitorica-Yrezabal
  • Gen Zhang


We report the stereoselective synthesis of a
left-handed trefoil knot from a tri(2,6-
pyridinedicarboxamide) oligomer with six chiral centers using
a lanthanide(III) ion template. The oligomer folds around
the lanthanide ion to form an overhand knot complex of
single handedness. Subsequent joining of the overhand knot
end groups by ring-closing olefin metathesis affords a single
stereoisomer of the trefoil knot in 90% yield. The knot topology
and handedness was confirmed by NMR spectroscopy,
mass spectrometry and X-ray crystallography. The pseudo-
D3-symmetric knot was employed as an asymmetric catalyst
in Mukaiyama aldol reactions, generating enantioselectivities
of up to 83:17 er, significantly higher than those obtained
with a comparable unknotted ligand complex.

Bibliographical metadata

Original languageEnglish
JournalJournal of the American Chemical Society
Issue number40
Early online date26 Sep 2016
StatePublished - 2016