A Fragment-Based Approach toward Substituted Trioxa[7]helicenes.

A series of novel substituted trioxa[7]helicenes have been successfully prepared by a one-pot palladium catalyzed C–H arylation reaction starting from readily prepared dibenzofuran fragments. The dinitro-substituted helicene was analyzed by X-ray crystallography revealing the occurrence of two distinct enantiomers in the asymmetric unit, which forms interesting supramolecular motifs in the crystal, based on weak H-bonding interactions. [ABSTRACT FROM AUTHOR]