In Search of Wasserman's Catenane

Authors：Baluna, Andrei S.; Galan, Albano; Leigh, David A. .^*; Smith, Gareth D.; Spence, Justin T. J.; Tetlow, Daniel J.; Vitorica-Yrezabal, Inigo J.; Zhang, Min

Source：Journal of the American Chemical Society, 2023, 145(17): 9825-9833.

DOI：10.1021/jacs.3c01939

• CARBON RINGS
• OXIDATION
• ROTAXANES

We repeat the earliest claimed [2]catenane syn-thesis, reported by Wasserman over 60 years ago, in order to ascertain whether or not a nontemplate, statistical synthesis by acyloin macrocyclization does indeed form mechanically inter-locked rings. The lack of direct experimental evidence for Wasserman's catenane has led to it being described as a "prophetic compound", a technical term used in patents for claimed molecules that have not yet been synthesized. Contemporary synthetic methods were used to reconstruct Wasserman's deuterium-labeled macrocycle and other building blocks on the 10-100 g reaction scale necessary to generate, in principle, similar to 1 mg of catenane. Modern spectrometric and spectroscopic tools and chemical techniques (including tandem mass spectrometry, deuterium nuclear magnetic resonance (NMR) spectroscopy, and fluorescent tag labeling) were brought to bear in an effort to detect, isolate, and prove the structure of a putative [2]catenane consisting of a 34-membered cyclic hydrocarbon mechanically linked with a 34-membered cyclic alpha-hydroxyketone.