Deracemization of Carbohelicenes by a Chiral Perylene Bisimide Cyclophane Template Catalyst

Deracemization describes the conversion of a racemic mixture chiral molecule into an enantioenriched or enantiopure compound without structural modifications. Herein, we report inherently perylene bisimide (PBI) cyclophane whose pocket is capable transforming [5]-helicene with enantiomeric excess 66 %. UV/Vis and fluorescence titration studies reveal this host composed two helically twisted PBI dyes has high binding affinities for respective homochiral carbohelicene guests, outstanding constants up to 3.9×1010 m?1 [4]-helicene. 2D NMR single-crystal X-ray analysis demonstrate that observed strong enantioselective carbohelicenes successful template-catalyzed deracemization can be explained by enzyme-like perfect shape complementarity macrocyclic supramolecular host.