New Heterocyclic Analogs of BCH- and CBC-Compounds

A series of new liquid crystalline compounds with BCH- and CBC- structures was synthesized. They differ from the known carbocyclic analogs by the 1,2,4-oxadiazole fragment placed in various positions of the long mesomorphic molecule. The cross-coupling reaction of the aromatic boric acids and bromides is a new way for mesogenic heterocycles design. The transition temperatures of these new liquid crystals are lower as compared with carbocyclic BCH- and CBC- analogs and significantly depend on the position of the nonlinear heterocyclic unit in the molecular chain.