One‐Step Construction of Five Successive Rings by Rhodium‐Catalyzed Intermolecular Double [2+2+2] Cycloaddition: Enantioenriched [9]Helicene‐Like Molecules

Abstract

Spiraling upwards: Enantioenriched fluorenone-containing [9]helicene-like molecules have been successfully synthesized through the formation of five successive rings by rhodium-catalyzed intermolecular double [2+2+2] cycloadditions of 2-naphthol-linked tetraynes with dialkynylketones (see scheme; cod=cycloocta-1,5-diene). Their unique crystal structures and photophysical properties have also been determined.