Synthesis and stereostructure of axially chiral polycyclic aromatic compounds

Abstract

Axially chiral binaphthyls have been well recognized as powerful chiral sources in asymmetric synthesis and molecular recognition. On the other hand, biaryl ethers in which two of aromatic rings connected via an oxygen atom have not been well documented as an axially chiral compound. Herein, we report the design, synthesis and stereostructure of novel biphenanthryl ethers as promising candidate for axially chiral polycyclic aromatic compounds. Upon photo-irradiation of stylene derivative in the presence of iodine, cyclization-aromatization reaction proceeded smoothly to give desired biphenanthryl ether, containing fluoro substituents at bay positions, in excellent yield. The crystal structure of biphenanthryl ether derivative clearly showed axial chirality.