Stereoselective Synthesis of a Topologically Chiral Molecule: The Trefoil Knot


  • We thank the Swiss National Science Foundation and the CNRS (CERC3 project on Toplogical Chirality) for financial support.


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Tying nice neat knots is demonstrated on a molecular level with the stereoselective synthesis of a trefoil knot. The key reaction was the completely stereoselective formation of a double-stranded helical precursor from two pinene–bipyridine threads around two CuI centers (the pinene moieties contain stereogenic centers). The helix was then transformed through several steps into 1; demetallation of the complex 1 yielded the configurationally predetermined free trefoil knot.