Abstract: Process for cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates.In a process for preparing polycyclic aromatic compounds by cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates under palladium catalysis in the presence of at least one water-soluble complex ligand, the reaction medium comprises an aqueous and an organic phase and the palladium is added in the form of a palladium compound soluble in the organic phase.Polycyclic aromatic compounds can thus be prepared economically and in very good yields and simultaneously very high purity, in particular without contamination by the complexing ligands.

Abstract: 1-Fluoroisoquinolinc derivatives of the formula (I)R.sup.1 (--M.sup.1).sub.a (--A.sup.1 --M.sup.2).sub.b (--A.sup.2 --M.sup.3).sub.c --B(--M.sup.4 --A.sup.3).sub.d (--M.sup.5 --A.sup.4).sub.e (--M.sup.6).sub.f --R.sup.2 ( 1)where the group B is ##STR1## R.sup.1 and R.sup.2 are alkyl radicals having 1 to 20 carbon atoms; M.sup.1, M.sup.2, M.sup.3, M.sup.4, M.sup.5, and M.sup.6 are --O--, --CO--O, --O--CO-- or a single bond;A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are 1,4-phenylene, pyrimidine-2,5-diyl or trans-1,4-cyclohexylene, anda, b, c, d, e and f are zero or one, with the proviso that the sum of b, c, d and e is 0, 1, or 2 are disclosed as well as their used in liquid-crystalline mixtures.

Abstract: 1,8,8-Trifluoro-5,6,7,8-tetrahydroisoquinoline derivatives, and their use in liquid-crystalline mixtures 1,8,8-Trifluoro-5,6,7,8-tetrahydroisoquinoline derivatives of the formula (I)R.sup.1 (--M.sup.1).sub.a (--A.sup.1 --M.sup.2).sub.b (--A.sup.2 --M.sup.3).sub.c --B(--M.sup.4 --A.sup.3).sub.d (--M.sup.5 --A.sup.4).sub.e (--M.sup.6).sub.f --R.sup.2 (I)in which the symbols and indices have the following meanings:the group B is ##STR1## R.sup.1 and R.sup.2 are, for example, alkyl radicals having 1 to 20 carbon atoms;M.sup.1, M.sup.2, M.sup.3, M.sup.4, M.sup.5 and M.sup.6 are, for example, --O--, --CO--O--, --O--CO-- or a single bond;A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are, for example, 1,4-phenylene, pyrimidine-2,5-diyl or trans-1,4-cyclohexylene, anda, b, c, d, e and f are zero or one, with the proviso that the sum of b, c, d and e is 0, 1 or 2.

Abstract: Fluorinated phenanthrene derivatives of the formula (I) ##STR1## in which the symbols and indices have the following meanings: E.sup.1, E.sup.2, E.sup.3, E.sup.4, E.sup.5 and E.sup.6 are identical or different and are --N--, --CF-- or --CH--;G is --CF.sub.2 CF.sub.2 -- or --CF.dbd.CF--;R.sup.1 and R.sup.2 are, for example, alkyl or alkoxy;M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are, for example, O, --CO--O--, --O--CO-- or a single bond;A.sup.1 and A.sup.2 are, for example, 1,4-phenylene or pyrimidine-2,5-diyl;m and n are zero or one, but in total are not more than one,are suitable as components of liquid-crystalline mixtures.

Abstract: 1,8-Difluoroisoquinoline derivatives of the formula (I)R.sup.1 (--M.sup.1).sub.a (--A.sup.1 --M.sup.2).sub.b (--A.sup.2 --M.sup.3).sub.c --B(--M.sup.4 --A.sup.3).sub.d (--M.sup.5 --A.sup.4).sub.e (--M.sup.6).sub.f --R.sup.2 (I)in which the symbols and indices have the following meanings: the group B is ##STR1## R.sup.1 and R.sup.2 are, for example, alkyl radicals having 1 to 20 carbon atoms;M.sup.1, M.sup.2, M.sup.3, M.sup.4, M.sup.5 and M.sup.6 are, for example, --O--, --CO--O--, --O--CO-- or a single bond;A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are, for example, 1,4-phenylene, pyrimidine-2,5-diyl or trans-1,4-cyclohexylene, anda, b, c, d, e and f are zero or one, with the proviso that the sum of b, c, d and e is 0, 1 or 2.The compounds of the formula (I) are colorless in the pure state and generally form liquid-crystalline mesophases in a temperature range which is favorably located for electro-optical use. They are stable chemically, thermally and to light.

Abstract: 1-Fluoro-6,7-dihydro-5H-isoquinolin-8-one derivatives of the formula (I)R.sup.1 (--M.sup.1).sub.a (--A.sup.1 --M.sup.2).sub.b (--A.sup.2 --M.sup.3).sub.c --B(--M.sup.4 --A.sup.3).sub.d (--M.sup.5 --A.sup.4).sub.e (--M.sup.6).sub.f --R.sup.2 (I)where B, R.sup.1, R.sup.2, M.sup.1, M.sup.2, M.sup.3, M.sup.4, M.sup.5 M.sup.6, A.sup.1, A.sup.2, A.sup.3, and A.sup.4 are various defined substituents and a, b, c, d, e are zero or one, with the proviso that the sum of b, c, d, and e is 0, 1 or 2, are disclosed. These derivatives are used in liquid-crystalline mixtures.

Abstract: Bifunctional compounds of the formula (I), ##STR1## in which: ##STR2## are naphthalene-2,6-diyl or ##STR3## is naphthalene-2,6-diyl or ##STR4## U, X, Y and Z are --CH.dbd., --CF.dbd. and --N.dbd., with the proviso that --CF.dbd. and --N.dbd. may each only be represented at most twice per six-membered ring, and that --CF.dbd. and --N.dbd. may not at the same time be represented twice in a six-membered ring;Hal is Cl, Br or I; or H, if X and/or Y are --CF.dbd.R.sup.3 is CH.sub.3 or OCH.sub.3l is 0 or 1m and n are 0, 1, 2 or 3.The compounds of the formula I are useful intermediates for the preparation of liquid-crystalline mixtures.

Abstract: Thiadiazole derivatives of the formula (I)X-B-A.sup.1 -(M.sup.1 -A.sup.2 -).sub.m (M.sup.2 -A.sup.3).sub.n -R.sup.1(I )in which the symbols and indices have the following meanings:X is Cl, Br or I;B is 1,3,4-thiadiazole-2,5-diyl;A.sup.1, A.sup.2 and A.sup.3 are identical or different and are substituted or unsubstituted 1,4-phenylene, pyrazine-2,5-diyl, pyridazine-3,6-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene, 1,3,4-thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl, 1,3-thiazole-2,4-diyl, 1,3-thiazole-2,5-diyl, thiophene-2,4-diyl, thiophene-2,5-diyl, piperazine-1,4-diyl, piperazine-2,5-diyl, naphthalene-2,6-diyl, bicyclo?2.2.2!octane-1,4-diyl, or 1,3-dioxaborinane-2,5-diyl;M.sup.1 and M.sup.2 are identical or different and are --CO--O--, --O--CO--, --O--CO--O--, --O--CS--O--, --CH.sub.2 --O--, --O--CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C-- or a single bond;R.sup.

Abstract: Novel oxiranylmethyl ethers can advantageously be employed in liquid-crystal mixtures since they have high spontaneous-polarization values and features in their molecular structure which make them miscible with other components of liquid-crystal systems.

Abstract: A process for preparing polycyclic aromatic compounds by cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates in the presence of metallic palladium as catalyst comprises adding to the reactiona) at least one water-soluble complexing ligand andb) sufficient water for the reaction mixture to form an aqueous phase.The reaction of the invention proceeds chemoselectively so that even electrophilic groups such as esters or nitriles do not have an adverse effect on the course of the reaction.The use according to the invention of a water-soluble complexing ligand in an aqueous phase enables polycyclic aromatic compounds to be prepared in very good yields and at the same time very high purity, in particular without contamination by the complexing ligands.

Abstract: 3-Chloropyridines, process for their preparation, and their use in liquid-crystal mixturesA 3-chloropyridine of the formula (I) ##STR1## in which the symbols have the following meaning: R.sup.1 and R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are identical or different and are, for example, 1,4-phenylene, pyrazine-2,5-diyl or trans-1,4-cyclohexylene, M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are identical or different and are, for example, --O-- or --CO--O--, R.sup.3, R.sup.4, R.sup.6 and R.sup.7, independently of one another are, for example, H or straight-chain or branched alkyl, M.sup.5 is, for example, --O--CO-- or a single bond, k, l, m, n, o, p, q and r are zero or one, with the proviso that the sum k+m+p+r is less than 4 and greater than zero, can advantageously be employed as a component in ferroelectric liquid-crystal mixtures.

Abstract: An aromatic compound of the formula (I)R.sup.1 (--A.sup.1).sub.a (--M.sup.1).sub.b (--A.sup.2).sub.c (--M.sup.2).sub.d --B(--M.sup.3).sub.c (--A.sup.3).sub.f (--M.sup.4).sub.g (--A.sup.4).sub.h --R.sub.2 (I)in whichB is one of the two following aromatic groups: ##STR1## Q.sup.1, Q.sup.2, Q.sup.3 and Q.sup.4 are identical or different and are CH.sub.2, CF.sub.2, N--R.sup.3, S, O or C.dbd.O;P.sup.1, P.sup.2 and P.sup.3 are identical or different and are C--H, C--F or N; andthe remaining symbols and indicies define mesogenic radicals, The compounds are suitable as components of liquid-crystalline mixtures.

Abstract: A process for preparing polycyclic aromatic compounds by cross-coupling aromatic boronic acids with aromatic halogen compounds or perfluoroalkylsulfonates in the presence of metallic palladium, if desired applied to a support material, as catalyst, wherein the coupling is carried out in the presence of a ligand and a base. The process of the invention allows the yield of polycyclic aromatic compounds to be significantly increased in comparison with processes not using a ligand and thus allows a yield optimum for the Pd(0)-catalyzed cross-coupling of aromatic boronic acids with aromatic halogen compounds to be achieved.

Abstract: The use of a compound of the formula I, in liquid crystal mixtures,R.sup.1 (--A.sup.1).sub.a (--M.sup.1).sub.b (--A.sup.2)--O--CF(CF.sub.3)--COO--(--A.sup.3)(--M.sup.2).sub.c (--A.sup.4).sub.d --R.sup.2 Iin which the symbols and indices have the following meanings:R.sup.1 and R.sup.2 are identical or different and are hydrogen, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms (with or without asymmetrical carbon atoms), where one or more --CH.sub.2 -- groups may also be replaced by --O--, --CO--, cyclopropane-1,2-diyl, --Si(CH.sub.3).sub.2 --, with the proviso that oxygen atoms must not be bonded directly to one another, and/or one or more H atoms of the alkyl radical may be substituted by --F; M.sup.1 and M.sup.2 are identical or different and are --CO--O--, --O--CO--, or a single bond;A.sup.1, A.sup.2, A.sup.3 and A.sup.

Abstract: A smectic liquid-crystal mixture containing rod-shaped molecules having only one side chain and certain phenylpyrimidine derivatives. The liquid-crystal mixtures according to the invention are distinguished by a low melting point and a high S.sub.C /S.sub.A phase-transition temperature. The use of bisesters of the formula I allows the number of phenylpyrimidine derivatives in the mixtures according to the invention to be significantly reduced. Ferroelectric mixtures according to the invention have, in particular, high contrast, good alignment, a large margin, low flicker and a large angle in the chevron geometry.

Abstract: Azaaromatic compounds of the formula I ##STR1## in which R.sup.1 and R.sup.2 are, for example, alkyl radicals,M is, for example, --O--, --COO-- or --O--CO--O--,A is an aromatic or heteroaromatic ring,V, X, Y and Z are CH, CF or N,a,b,c,d,m and n are 0 or 1, where m+n is 0 or 1 and a+d is 0 or 1.The compounds of the formula I are suitable as components of liquid-crystal mixtures.

Abstract: Process for preparing highly pure enantiomers of oxirane alcohols, which comprises recrystallizing a mixture of the isomeric oxirane alcohols, in which the desired enantiomer is present in an excess of at least 60% ee, in a solvent or solvent mixture at a temperature just below the melting point of the oxirane alcohol.Oxirane alcohols prepared according to the invention are distinguished by high enantiomer purity. Ferroelectric liquid crystals, which contain highly pure enantiomers of oxirane alcohols according to the invention and/or derivatives derived therefrom, have particularly short switching times.

Abstract: Decomposition-sensitive complex ligands can be stabilized by derivatizing them with the aid of bulky secondary or tertiary carboxylic acids or sulfonic acids. These stabilized derivatives can be added to alignment layers and liquid-crystal mixtures and increase the contrast and brightness in the FLC display.

Abstract: A smectic liquid-crystal mixture comprisingA. at least one compound of the formula (I) ##STR1## B. at least one compound of the formula (III) ##STR2## C. compounds of the formula (IV)R.sup.1 --O--CO--O--(--A.sup.1).sub.a (--M.sup.1).sub.b (--A.sup.2).sub.c (--M.sup.2).sub.d (--A.sup.3).sub.e (--O).sub.f --R.sup.2 (IV)in which:R.sup.1 and R.sup.2 are identical or different and are a straight-chain or branched alkyl group having 1 to 22 or 3 to 22 carbon atoms respectively,A.sup.1, A.sup.2 and A.sup.3 are identical or different and are 1,4-phenylene, where one or two H atoms may also be replaced by F, 2,5-pyrimidinediyl,and further smectogenic compounds and, if desired, dopants. The mixture exhibits a low melting point and a broad S.sub.c phase.

Abstract: Smectic liquid-crystal mixture A liquid-crystalline mixture comprises, inter aliaA. at least one compound of the formula I ##STR1## and/or at least one compound of the formula (II) ##STR2## B. at least one compound of the formula (III)R.sup.1 (-A.sup.1).sub.a (-M.sup.1).sub.b (-A.sup.2).sub.c (-M.sup.2).sub.d (-A.sup.3).sub.e (-M.sup.3).sub.f (-A.sup.4)-H (III)C. and at least one compound of the formula (IV) ##STR3##The mixture has a low melting point and a broad S.sub.c phase range.