Chiral Self‐Sorting of Diformylated N‐Hetero‐ortho‐phenylene Hexamers by Macrocyclization with Aromatic Diamines

Abstract

Diformylated N-Hetero-ortho-phenylene hexamers (4 a and 4 b) were prepared from 2,3-dichloropyrydine by palladium-catalyzed coupling reactions and deprotection. Three helical conformers of 4, corresponding to the rotations of the terminal phenylenes, were observed in 1 H-NMR spectra of solution state. Chiral self-sorting of 4 a occurred by macrocyclization with para-phenylenediamine in the presence of para-toluenesulfonic acid. The homochiral structure (PP and MM) containing two N-hetero-ortho-phenylene hexamer (N-oP 6 ) moieties was revealed by 1 H-NMR and mass spectra, as well as single-crystal X-ray analysis. Using (+)-or (À )-camphorsulfonic acid was also effective in the formation of the homochiral macrocycle and also induced a chiral bias in the helical folding of N-oP 6 moieties. Moreover, planar chiral self-sorting of the bridged moieties was also achieved by using 4 a and 1,5diaminonaphthalene.