A Triply [5]Helicene-Bridged (1,3,5)Cyclophane

Angew Chem Int Ed Engl. 2023 Jul 10;62(28):e202304058. doi: 10.1002/anie.202304058. Epub 2023 Jun 6.

Abstract

A rigid propeller-shaped conjugated triple macrocycle consisting of two nearly perfectly stacked benzene rings and three linking [5]helicene moieties has been synthesized using a glyoxylic Perkin approach. Analysis of the electron delocalization in this atypical aromatic molecule revealed global aromaticity and a 78 π-electron circuit along the edge of its triple loop, to the detriment of the two 6 π-electron circuits in the two stacked benzene rings.

Keywords: Aromaticity; Cyclophane; Helicene; Macrocycle; Perkin Reaction.