A Trefoil Macrocycle Synthesized by 3-Fold Benzannulation

A new trefoil-shaped molecular architecture consisting of three conjugated macrocycles was synthesized through an unprecedented 3-fold copper catalyzed [4 + 2] benzannulation. DFT calculations indicate that the most stable conformation of this trefoil macrocycle is D-symmetric. In agreement with the calculated results, the trefoil macrocycle in single crystals exists as a pair of enantiomers with D-symmetry and exhibits interesting honeycomb-like supramolecular structures.