Synthesis of highly chiral multisubstituted binaphthyl compounds as potential new biaxial nematic and NLO materials

Abstract

Abstract A number of multi substituted binaphthalene compounds were synthesized in an attempt to obtain a highly chiral biaxial nematic (Nb) phase or a good NLO material. Introduction of two pairs of substituents into the binaphthalene molecule with one of these being a nitrile group and R = C10 was successful but neither this compound nor the above esters showed any mesophases. Introduction of additional pairs of substituents proved to be difficult. Friedel-Crafts acylation to add a third pair through a ketone gave complicated mixtures of products obtained by cleavage of the ether followed by acylation. Bromination, which could lead to either the necessary nitrile substituent or esters via the acid obtained from the nitrile generally gave mixtures of bromides as expected. Some of these could be separated by chromatography and successfully converted to the nitrile. However, attempts to hydrolyze these nitrile groups usually gave mixtures of various products of incomplete hydrolysis producing compounds tha...