LC diketones: synthesis, transformations and mesomorphic properties

Polyfunctional intermediates for the preparation of liquid-crystalline and anisotropic materials

“…(F) 3-Acetyl-6-arylcyclohex-2-enones (I.6) and other substituted cyclohex-2-enones (I.7-I.11) containing additional functional groups. These ketones, as we reported before [42,43], can be synthesised by the interaction of the corresponding Mannich salts with acetylacetone or 2-(2-cyanoethyl)-, 2-(2-trifluoromethylethyl)-, 2-allylsubstituted acetoacetic esters or 2-acetylbutyrolactone, or other similar β-dicarbonylic compounds. (Scheme 11).…”

“…It should be noted that 4-aryl-2-hydroxyacetophenones (51), as our investigations have shown [43], are promising intermediates for the preparation of various anisotropic metal complexes and dyes (57-61) (Scheme 14)…”

“…from the corresponding 3,6-disubstituted cyclohex-2-enones (I.5) and 2,5-disubstituted cyclohexanones (II.2) in the aromatisation of cyclohexenone or modifications of cyclohexanone fragments (Scheme 10) [37]. Investigations of the electro-optic and dynamic parameters of LC mixtures containing compounds (37)(38)(39)(40)(41)(42)(43)(44), presented in Table 5, have shown that they are really promising components of the materials for VA displays.…”

“…These compounds (37)(38)(39)(40)(41)(42)(43)(44) and polyfluoroderivatives similar to them are characterised a high value of negative dielectric anisotropy (-Δϵ) and allow the threshold voltage of the liquid-crystalline mixtures to decrease. Using the polyfluoroderivatives, we have developed the LC compositions with low the threshold voltage, fast switch-on and switch-off times and a wide temperature range of the nematic phase (from -30°C to +105°C) for VA displays [9,13,14].…”

Prospects of the Development of New Approaches of the Preparation of Anisotropic Compounds and Materials

“…3-Acetyl-6-arylcyclohex-2-enones (I.5) and other substituted cyclohex-2-enones (I.6-I.10) containing additional functional groups (Scheme 9) [42]. It should be noted that 4-aryl-2-hydroxyacetophenones (50) can be used for the preparation of various anisotropic metal complexes and dyers (56-60) (Scheme 12) [43]. 5-Substituted cyclohexan-1,3-diones (III) similar to 3,6-disubstituted cyclohex-2-enones (I) can be successfully used for the preparation of anisotropic polycyclic aromatic hydrocarbons (61-70), containing various functional groups in the lateral positions (Scheme 13) [24].…”