Conjugated figure-of-eight macrocycles derived from the anthracene photodimer: synthetic execution through intramolecular cyclization and topological manipulation through ring expansion

Abstract

Dual-cavity macrocycles with extended π-conjugation are synthetically challenging yet attractive targets, exhibiting intriguing topologies and functional properties. In this work, a series of conjugated figure-of-eight macrocycles consisting of fused aromatic subunits are facilely prepared employing intramolecular cyclizations from precursors containing an anthracene photodimer core and phenanthrene-derived side arms. In addition to functioning as an X-shaped template for cyclizations, the anthracene photodimer core also enables late-stage topological manipulations by cycloreversion, affording conjugated lemniscular macrocycles with D₂ symmetry.