The synthesis of chiral fluorinated 4-alkyl-4′-[(4-alkylphenyl)ethynyl]biphenyls

We have designed, synthesized, and evaluated the physical properties of new fluorinated phenyltolane based chiral liquid crystal materials with 2-methylbutyl chains. This type of fluoro-substitution in chemical combination with a phenyltolane core brings a surprising improvement to the mesomorphic properties. The investigated compounds exhibit broad temperature ranges for the N∗ phase and very low melting points. All homologues exhibited Blue Phase. We have applied a Cu-catalyzed cross-coupling reaction between aryl Grignard reagents and alkyl bromides for the synthesis of the products.