Synthesis of Symmetrical and Unsymmetrical Triphenylene Discotic Liquid Crystals Using Antimony(V)Chloride Under Scholl Oxidation

Abstract

Triphenylene-based discotic liquid crystals, useful in studying the energy and charge migration in self-organized systems, are the most widely synthesized and studied discotic liquid crystals. In this paper, we report an efficient synthetic procedure for the preparation of symmetrical and unsymmetrical triphenylene discotic liquid crystals using antimony pentachloride as a novel reagent. Scholl oxidative trimarization of 1,2-dialkoxybenzenes with SbCl5 yields hexaalkoxytriphenylenes in good yield, while the oxidative coupling of a 3,3’,4,4’-tetraalkoxybiphenyl with a 1,2,3-trialkoxybenzene affords an unsymmetrically substituted heptaalkoxy-triphenylene derivative. The potential of this new reagent was compared with the other known reagents for the synthesis of alkoxytriphenylenes