DE102010034968B4 - Polymerizable compounds and liquid-crystal media - Google Patents

Abstract

enthält,
worin
R^1' bis R^5' jeweils unabhängig voneinander Wasserstoff, geradkettiges oder verzweigtes Alkyl, Alkenyl, Alkoxy oder Alkoxymethyl mit 1 bis 12 C-Atomen,
X¹ bis X⁵ jeweils unabhängig voneinander -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR⁰⁰-, -NR⁰⁰-CO-, -NR⁰⁰-CO-NR⁰⁰-, -OCH2-, -CH₂O-, -SCH₂-, -CH₂S-, -CF₂O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR⁰-, -CY²=CY³-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- oder eine Einfachbindung,
R⁰ und R⁰⁰ jeweils unabhängig voneinander H oder Alkyl mit 1 bis 12 C-Atomen,
Y² und Y³ jeweils unabhängig voneinander H, F, Cl oder CN,
P¹ bis P⁵ jeweils unabhängig voneinander eine polymerisierbare Gruppe und
Sp¹ bis Sp⁵ jeweils unabhängig voneinander eine Abstandsgruppe oder eine Einfachbindung bedeuten,
oder welches ein Polymer umfassend eine oder mehrere Verbindungen ausgewählt aus den Verbindungen der Formeln IA-1 bis IA-10 enthält.Liquid-crystalline medium which comprises one or more compounds selected from the compounds of the formulas IA-1 to IA-10

contains
wherein
R ^{1 '} to R ^{5' are} each independently of one another hydrogen, straight-chain or branched alkyl, alkenyl, alkoxy or alkoxymethyl having 1 to 12 C atoms,
X ¹ to X ^{5 are} each independently of one another -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ⁰⁰ -, -NR ⁰⁰ -CO-, -NR ⁰⁰ -CO-NR ⁰⁰ -, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CF ₂ CH ₂ - , -CH2CF2-, -CF2CF2-, -CH = N-, -N = CH-, -N = N-, -CH = CR ⁰ -, -CY ² = CY ³ -, -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or a single bond,
R ⁰ and R ^{00 are} each independently H or alkyl of 1 to 12 C atoms,
Y ² and Y ^{3 are} each independently H, F, Cl or CN,
P ¹ to P ^{5 are} each independently a polymerizable group and
Sp ¹ to Sp ⁵ each independently represent a spacer group or a single bond,
or which contains a polymer comprising one or more compounds selected from the compounds of the formulas IA-1 to IA-10.

Description

The present invention relates to liquid-crystalline media (LC media) containing one or more polymerizable compounds of the formulas IA-1 to IA-10 or comprising a polymer which contains one or more compounds of the formulas IA-1 to IA-10, and also electro-optical Display elements containing these LC media. The compounds contained are preferably sugar derivatives.

In the prior art media for display elements are known, which operate in the liquid-crystalline blue phase (short: blue phase) ( WO 04/046805 A1 . WO 2008/061606 A1 ). WO 2008/061606 A1 describes in particular the use of reactive mesogens based on cyclohexylene structural elements.

The blue phase is usually observed at the transition from the nematic to the optically isotropic state. The medium in the liquid-crystalline blue phase can be blue, as the name suggests, but also colorless. The aim of previous efforts has been to extend the temperature range of the blue phase from less than one degree to a practically usable range (cf. H. Kikuchi et al., Nature Materials (2002), 1 (1), 64-68 ; Kikuchi, H. et al., Polymeric Materials Science and Engineering, (2003), 89, 90-91 ).

WO 2005/080529 A1 describes polymer-stabilized blue phases with mono- and multireactive monomers.

In the JP 2005 283 632 Carbohydrate-derived polymerizable compounds are described for use in negative recording materials. With the production process described therein, the compounds of the invention can not be prepared so that they would be suitable for use in LC media. The process does not achieve completely functionalized sugar derivatives but leaves OH functions open. Depicted are the structures A and B:

In the WO1994 / 014828 a tetraacrylate derived from the so-called. Methyl Gluceth-20 (MG-20, Glucam E-20) is described. This is a methylglucoside with an average total of about 20 ethyleneoxy units (ethylene glycol units), whereby the glycol units in the ring are counted. Formal Thus, these materials are alkoxy polymers of non-uniform composition. The general structure is roughly described by the following formula.

For MG-20 (Glucam E-20), the sum of the parameters a, b, c, and d is then about 20, and the values for a, b, c, and d may differ. Because the composition of these materials is not uniform and is subject to variations, polymerizable compounds derived therefrom are unsuitable for building finely tuned blue neutralization polymer networks. Reproducible results for such complex structures as blue phases can not be achieved with such compounds. goal of WO1994 / 014828 it was to provide ion-conducting polymeric materials for example for electrolysis cells.

In the US 5248747 and a similar publication ( US 5116961 ), the use of 1 ', 6', 6'-trimethylacroloyl-2,3,3 ', 4,4'-penta-O-methylsucrose (D) as crosslinking agents in polymerization with, for example, acrylic acid (esters), methacrylic acid (esters ) or acrylamide monomers.

The synthesis of the compound D is described in the US 5302676 described. The structure is chosen such that secondary hydroxy functions of the sucrose are methylated and primary hydroxy functions are functionalized to methacrylates in the course of the overall 4-stage synthesis.

DE 195 20 704 A1 describes polymerizable chiral compounds having mesogenic groups for use in liquid crystals. US 4,560,534 relates to certain materials for use in the field of analyte detection, which inter alia describe substituted furan and pyran structures.

The polymer-stabilized blue phases described hitherto use in practice as monomers a monoreactive non-mesogenic monomer together with a direactive monomer (RM257).

• - breiter Temperaturbereich der blauen Phase,
• - schnelle Schaltzeit,
• - geringe Klärpunktsdifferenz beim Polymerisieren,
• - geringe Betriebsspannung (V_op),
• - geringe Variation der Betriebsspannung mit der Temperatur,
• - geringe Hysterese der Transmission einer Zelle bei Änderung der Betriebsspannung zum Erzielen definierter Graustufen.

It was an object of the present invention to find suitable monomers and corresponding polymers for the stabilization of blue phases. The polymer should have the following effects on the properties of the stabilized LC phase:

• wide temperature range of the blue phase,
• - fast switching time,
• small separation point difference during polymerization,
• low operating voltage (V _op ),
• - slight variation of the operating voltage with the temperature,
• low hysteresis of the transmission of a cell when the operating voltage changes to achieve defined gray levels.

It also requires monomer materials that have a good voltage holding ratio (VHR), high clearing points, and are stable to light and temperature stress. Furthermore, a good solubility in LC materials or a good miscibility with the LC material is necessary to achieve a good distribution in the LC host.

The present invention aims to provide, in particular, improved reactive polymerizable compounds which are capable of stabilizing blue phases and which are suitable for producing LC materials having improved properties.

This object is achieved by the liquid-crystalline medium according to claim 1.

P

eine polymerisierbare Gruppe, und

Sp

eine Abstandsgruppe oder eine Einfachbindung.

Herein mean

P

a polymerizable group, and

sp

a spacer group or a single bond.

The polymerizable group P is a group suitable for a polymerization reaction such as radical or ionic chain polymerization, polyaddition or polycondensation, or for a polymer-analogous reaction, for example, addition or condensation to a polymer main chain. Particular preference is given to groups for chain polymerization, in particular those containing a C =C double bond or C≡C triple bond, and groups suitable for polymerization with ring opening, for example oxetane or epoxy groups.

CH2=CW²-(O)_k3-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-CO-NH-,CH₃-CH=CH-O-, (CH₂=CH)₂CH-OCO-, (CH₂=CH-CH₂)₂CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW²W³-, HS-CW²W³-, HW²N-, HO-CW²W³-NH-, CH₂=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH-, HOOC-, OCN-, und W⁴W⁵W⁶Si-, worin W¹ H, F, Cl, CN, CF₃, Phenyl oder Alkyl mit 1 bis 5 C-Atomen, insbesondere H, F, Cl oder CH₃ bedeutet, W² und W³ jeweils unabhängig voneinander H oder Alkyl mit 1 bis 5 C-Atomen, insbesondere H, Methyl, Ethyl oder n-Propyl bedeuten, W⁴, W⁵ und W⁶ jeweils unabhängig voneinander Cl, Oxaalkyl oder Oxacarbonylalkyl mit 1 bis 5 C-Atomen bedeuten, W⁷ und W⁸ jeweils unabhängig voneinander H, Cl oder Alkyl mit 1 bis 5 C-Atomen bedeuten, Phe 1,4-Phenylen bedeutet, welches optional mit ein oder mehreren Resten L wie oben definiert ist, k₁, k₂ und k₃ jeweils unabhängig voneinander 0 oder 1 bedeuten, k₃ vorzugsweise 1 bedeutet.Preferred groups P are selected from CH ₂ = CW ¹ -COO-, CH ₂ = CW ¹ -CO-,

CH 2 = CW ² - (O) _k3 -, CW ¹ = CH-CO- (O) _k3 -, CW ¹ = CH-CO-NH-, CH ₂ = CW ¹ -CO-NH-, CH ₃ -CH = CH-O-, (CH ₂ = CH) ₂ CH-OCO-, (CH ₂ = CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ = CH) ₂ CH-O-, (CH ₂ = CH-CH ₂ ) ₂ N -, (CH 2 = CH-CH 2) 2N-CO-, HO-CW ² W ³ -, HS-CW ² W ³ -, HW ² N-, HO-CW ² W ³ -NH-, CH ₂ = CW ¹ -CO-NH-, CH ₂ = CH- (COO) _k1 -Phe- (O) _k2 -, CH ₂ = CH- (CO) _k1 -Phe- (O) _k2 -, Phe-CH = CH-, HOOC -, OCN-, and W ⁴ W ⁵ W ⁶ Si-, where W ^{1 is} H, F, Cl, CN, CF ₃ , phenyl or alkyl having 1 to 5 carbon atoms, in particular H, F, Cl or CH ₃ , W ² and W ³ each independently of one another are H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W ⁴ , W ⁵ and W ⁶ each independently of one another Cl, oxaalkyl or oxacarbonylalkyl with 1 to 5 C atoms, W ⁷ and W ⁸ each, independently of one another, denote H, Cl or alkyl having 1 to 5 C atoms, Phe means 1,4-phenylene, which is optionally defined by one or more radicals L as defined above, k ₁ , k ₂ and k _{3 are} each independently 0 or 1 bed e, k ₃ preferably 1 means.

und

Particularly preferred groups P are CH ₂ = CW ¹ -COO-, in particular CH ₂ = CH-COO-, CH ₂ = C (CH ₃ ) -COO- and CH ₂ = CF-COO-, furthermore CH ₂ = CH-O -, (CH ₂ = CH) ₂ CH-OCO-, (CH ₂ = CH) ₂ CH-O-,

and

Very particularly preferred groups P are vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, in particular acrylate and methacrylate.

Depending on the number of polymerizable groups per molecule, the monomers used according to the invention are suitable for the formation of polymers of different crosslinking strengths.

The term "spacer" or "spacer group", also referred to below as "Sp", is known to the person skilled in the art and described in the literature, see, for example, Pure Appl. Chem. 73 (5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368 , Unless otherwise indicated, the term "spacer" or "spacer" above and below denotes a flexible group which, in a polymerisable liquid-crystalline or mesogenic compound, bonds together the mesogenic group and the polymerizable group (s).

Sp'

Alkylen mit 1 bis 24, vorzugsweise 3 bis 12 C-Atomen, besonders bevorzugt 4 bis 12 C-Atomen bedeutet, welches optional durch F, Cl, Br, I oder CN ein- oder mehrfach substituiert ist, und worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander so durch -O-, -S-, -NH-, -NR⁰-, -SiR⁰⁰R⁰⁰⁰-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -NR⁰⁰-CO-O-, -O-CO-NR⁰⁰-, -NR⁰⁰-CO-NR⁰⁰-, -CH=CH- oder -C=C- so ersetzt sein können, dass O- und/oder S-Atome nicht direkt miteinander verknüpft sind, wobei bevorzugt eine oder keine CH₂-Gruppe ersetzt wird,

X

-O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR⁰⁰-, -NR⁰⁰-CO-, -NR⁰⁰-CO-NR⁰⁰-, -OCH₂-, -CH₂O-, -SCH₂-, -CH₂S-, -CF₂O-, -OCF₂-, -CF₂S-, -SCF2-, -CF₂CH₂-, -CH₂CF₂-, -CF₂CF₂-, -CH=N-, -N=CH-, -N=N-, -CH=CR⁰-, -CY²=CY³-, -C=C-, -CH=CH-COO-, -OCO-CH=CH- oder eine Einfachbindung bedeutet, vorzugsweise eine Einfachbindung, -O-, -OCO- oder -OCH₂-,

R⁰⁰ und R⁰⁰⁰

jeweils unabhängig voneinander H oder Alkyl mit 1 bis 12 C-Atomen bedeuten, und

Y² und Y³

jeweils unabhängig voneinander H, F, Cl oder CN bedeuten.

Preferred spacer groups Sp are selected from the formula Sp'-X, so that the radical P-Sp- corresponds to the formula P-Sp'-X-, where

Sp '

Alkylene having 1 to 24, preferably 3 to 12 C-atoms, more preferably 4 to 12 C-atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and wherein also one or more not each adjacent CH ₂ groups are each independently selected from -O-, -S-, -NH-, -NR ⁰ -, -SiR ⁰⁰ R ⁰⁰⁰ -, -CO-, -COO-, -OCO-, -OCO-O -, -S-CO-, -CO-S-, -NR ⁰⁰ -CO-O-, -O-CO-NR ⁰⁰ -, -NR ⁰⁰ -CO-NR ⁰⁰ -, -CH = CH- or -C = C- can be replaced so that O and / or S atoms are not directly linked to one another, preferably one or no CH ₂ group being replaced,

X

-O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ⁰⁰ -, -NR ⁰⁰ -CO-, -NR ⁰⁰ -CO-NR ⁰⁰ -, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH = N-, -N = CH-, -N = N-, -CH = CR ⁰ -, -CY ² = CY ³ -, -C = C, -CH = CH-COO-, -OCO-CH = CH- or a single bond, preferably a single bond, -O-, -OCO- or -OCH ₂ -,

R ⁰⁰ and R ⁰⁰⁰

each independently of one another are H or alkyl having 1 to 12 C atoms, and

Y ² and Y ³

each independently of one another are H, F, Cl or CN.

X is preferably -O-, -S-CO-, -COO-, -OCO-, -O-COO-, -CO-NR ⁰ -, -NR ⁰ -CO-, -NR ⁰ -CO-NR ⁰ - or a single bond.

Typical spacer groups Sp 'are, for example - (CH _{2) p1} -, - (CH ₂ CH ₂ O) _p2, -CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ -NH-CH ₂ CH ₂ - or - (SiR ⁰⁰ R ⁰⁰⁰ -O) _p1 -, wherein p1 is an integer from 1 to 24, preferably ≥ 3, p2 is an integer from 1 to 6, and R ⁰⁰ and R ^{000 have} the meanings given above.

Particularly preferred groups -X-Sp'- are - (CH ₂ ) _p1 -, -O- (CH ₂ ) _p1 -, -OCO- (CH ₂ ) _p1 -, -OCOO- (CH ₂ ) _p1 -, wherein p1 as defined above.

For example, particularly preferred groups Sp 'are each straight-chain ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene thioethylene, ethylene-N-methyl-iminoethylene, 1-methylalkylene , Ethenylene, propenylene and butenylene. More preferably, Sp 'is as defined above alkylene having 4 to 12 carbon atoms in the case where the group X represents a single bond or 3 to 12 carbon atoms in the event that, the group X is not a single bond.

Preferably, the groups -Sp-P are equal to one another.

The compounds used according to the invention are outstandingly suitable as polymerisable components in liquid-crystalline media. The polymer fulfills in every respect the task Requirements for the stabilization of liquid-crystalline phases, in particular of blue phases. Compared to conventional systems, a significant reduction in operating voltages is observed. At the same time, the tendency to form hysteresis in the transmission (gray values) decreases as a function of the (rising or falling) operating voltage. The compounds are also suitable in amounts of <1% as a polymerizable component in mixtures for PSA-VA type displays (cf. JP 10-036847 A . EP 1170626 A2 . US 6861107 . US 7169449 . US 2004/0191428 . US 2006/0066793 ) and for other PSA ('polymer sustained alignment') displays. In addition, in many cases, they can be easily prepared from commercial sugar compounds.

Particularly preferred compounds of the formulas IA-1 to IA-10 are derived from carbohydrates or also known as sugars. The terms carbohydrate or sugar are familiar to the person skilled in the art. These are oxidation products of polyhydric alcohols, ie hydroxyaldehydes (aldoses) or hydroxyketones (ketoses) and compounds derived therefrom and their condensates.

Particularly preferably used compounds are derived from monosaccharides (simple sugars) with five (pentoses, eg xylose) or six carbon atoms (hexoses, eg glucose). This allows a ring closure. The balance of this reaction is usually on the side of the cyclic hemiacetals. The open-chain form is usually negligible in solution and solid. In principle, the sugars can be present as furanose (5-membered ring) or pyranose (6-membered ring). Furthermore, a new stereocenter is formed during ring closure. Depending on the position of the OH group, a distinction is made between alpha and beta anomers.

Enantiomeric forms e.g. The glucose is identified by the prefixes D and L. In nature, only D-glucose occurs. L-glucose is only synthetically accessible.

Mischung aus α- und β-AnomerIn the following, only the substantially present form of a sugar is designated by its name. D-glucose, for example, exists almost exclusively in the pyranosefrom. D-glucose thus means below:

Mixture of α- and β-anomer

The wavy cusp at the anomeric center indicates that it is or can be a mixture of alpha and beta anomers. Detailed information on monosaccharides can be found in [Monosaccharides: Their Chemistry and their roles in natural products. Collins and R. Ferrier 1995 John Wiley & Sons, Chichester.].

Particularly preferably used compounds are derived, for example, from the following sugars:

The selection of the starting materials preferred for the synthesis of the compounds used is not limited to naturally occurring carbohydrates. Synthetically accessible sugars, enantiomers, derivatives or compounds modified by chemical reactions are also preferred starting materials for the compounds used according to claim 1. Thus, in the broadest sense polyhydroxypyrans are preferred starting materials for the compounds.

worin R^1' bis R^5' jeweils unabhängig voneinander Wasserstoff, geradkettiges oder verzweigtes Alkyl, Alkenyl, Alkoxy oder Alkoxymethyl mit 1 bis 12 C-Atomen, besonders bevorzugt Wasserstoff oder Alkoxy bedeuten, und worin
X¹ bis X⁵ wie X oben definiert sind,
Sp¹ bis Sp⁵ wie Sp oben defininert sind, und
P¹ bis P⁵ wie P oben definiert sind.The provided according to claim 1 structures of the formulas IA-1 to IA-10 are reproduced below, while a planar notation is selected. This includes all possible stereoisomers (enantiomers and diastereoisomers, see sugar structures above). Preferably in the sense of present invention are all possible stereoisomers resulting from the previously disclosed sugar structures. These can be stereoisomerically pure or as mixtures of stereoisomers.

in which R ^{1 '} to R ^{5' are} each independently of one another hydrogen, straight-chain or branched alkyl, alkenyl, alkoxy or alkoxymethyl having 1 to 12 C atoms, particularly preferably hydrogen or alkoxy, and
X ¹ to X ⁵ are defined as X above,
Sp ¹ to Sp ^{5 are defined} as Sp, and
P ¹ to P ⁵ are defined as P above.

Selected synthetic methods are exemplified starting from the most preferred monosaccharides. In particular, synthetic methods are described on the basis of D - (+) - xylose (1), L - (+) - arabinose (35), deoxy-D-ribose (16), D - (+) - glucose (70) and D- (+) - Galactose (116) described by way of example. This is intended to illustrate but not limit the present invention. The person skilled in the art can easily transfer the methods described to other starting materials.

Furthermore, particular attention is paid here to the compounds which have the particularly preferred polymerizable groups of the acrylate type, wherein generally the polymerizable group P is CH ₂ = CW ¹ -COO-, where W ^{1 is} as defined above. Of these, acrylates (CH ₂ = CH-COO-) and methacrylates (CH ₂ = C (CH ₃ ) -COO-) are very particularly preferred.

For the construction of spacers, the hydroxy functions of the carbohydrates are decisively used, thereby -O- is given as part of the spacer -Sp'-X. Such compounds are particularly preferred.

In a particularly preferred process, the construction of spacers Sp'-X is -OC (O) - (CH ₂ ) _p1 - by esterification with ω-bromoalkanoic acids 2. The locant ω here and in the following means that the substituent (here Bromine) is at the end of the chain, such as in 5-bromovaleric acid = 5-bromopentanoic acid. The compounds 3 thus obtained can then be converted by reaction with acrylic acids 4 (R = H or Me are preferred) to be polymerized compounds (eg compound 5 in Scheme 1).

For the synthesis of the intermediates 3 also ω-Bromalkansäurechloride 6 can be used. These are derived from the carboxylic acids 2, for example, by reaction with thionyl chloride.

Further preferred compounds are those with Sp'-X = -O- (CH ₂ ) _p1 -, wherein the parameter p1 is preferably greater than two.

A method to arrive at the most preferred compounds with p1 = 3 is shown in Scheme 3, again using the example of the reaction of D - (+) - xylose (1).

First, the sugar 1 is alkylated / allylated with allyl bromide (7) [ A. Leydet et al., J. Med. Chem. 1997, 40, 350-356 ]. Allyl bromide (7) is a strong enough alkylating agent to effectively and completely alkylate the secondary alcohol functions. Other alkylating agents, such as alkyl bromides or alkyl tosylates, are generally not sufficiently reactive to react sufficiently well with free sugars.

To construct the 1,3-propylene glycol spacer, a hydroboration-oxidation reaction then takes place to give compound 9. Compound 9 is then esterified either with acrylic acid chlorides (method A) or acrylic acids (method B) to give compounds 11. This reaction sequence can be carried out analogously with other starting materials which are preferred in the context of this invention.

The perallylated compound 8 or analogs are also suitable starting materials to obtain compounds with ethylene glycol spacers (Sp'-X '= O (CH ₂ ) ₂ -). The double bond is cleaved by ozonolysis, and the resulting aldehyde 12 is reduced to 13. However, it seems more advantageous to reduce the ozonide formed initially in ozonolysis (not shown) directly with sodium borohydride to aluminum oxide to give alcohol 13 [M. Dubber, T. Lindhorst, Carbohydr. Res. 1998, 310, 35-41] to obtain synthetically useful yields.

The free OH groups of the 1, n-glycol spacer can also be converted to the corresponding bromides 15. Such compounds are also valuable intermediates.

Alkyl bromides of the formula 15 or similar compounds (see Scheme 6, example of the reaction of deoxy-D-ribose (16)) can be reacted with carbon nucleophiles, eg, type 18 alkyl Grignard reagents to compounds with Sp'-X = -O- (CH ₂ ) ₃ (CH ₂ ) _p1 - be implemented. This is shown in Scheme 6 using the example of the reaction of 2-deoxy-D-ribose (16). The synthesis of the bromide 17 is carried out as described above. 17 is then reacted with Type 18 alkyl Grignard reagents (SG = protecting group). The alcohol protecting groups are removed to give the alcohols 20. The hydroxy functions can now be reacted with acrylic acid (derivatives) to give the compounds 21.

The OH groups of compounds such as compound 9 can of course also be converted into other suitable leaving groups. Apart from bromides, particular preference is also given to iodides, chlorides, tosylates, mesylates or triflates (in each case not shown).

The substrates obtained by ozonolysis of O-allylated compounds (see Scheme 4 or Scheme 7) are suitable for reacting in a Wittig reaction, for example with type 24 reagents (SG = protecting group, preferably silyl protecting group), compounds with alkenyl spacers (eg 27 in Scheme 7).

Wittig reagents of type 28 are particularly suitable when compounds with alkyl spacers of aldehydes such as 23 are to be prepared. The product of the Wittig reaction is hydrogenated, whereby the benzyl protecting group is split off and the double bonds are hydrogenated. The procedure is outlined in Scheme 8.

Generally, the use of protecting groups to synthesize intermediates such as 20 and 26 is not required. It can also WittigReagentien the type [HO- (CH _{2) p1} -CH ₂ PPh _3] ⁺ Br may be used (not shown.). Further preferred reagents for the synthesis of the compounds with Sp = - (CH ₂ ) -C = C- (CH ₂ ) _p1- or Sp = - (CH ₂ ) ₃ (CH ₂ ) _p1 - are bromoalkyl Wittigsalze 30. The Wittig reaction _(CH2) -C = C- (CH _{2) p1} - - of aldehydes such as 12 the compounds 31, which then, for example with acrylic acid 6 in the presence of base to give compounds with Sp = supplies reacted (. see example 32 in scheme 9) can be.

In order in this way compounds with Sp = - (CH _{2) 3} (CH _{2) p1} - (. Cf. compounds 34 in Scheme 10), the intermediate steps 31 will get hydrogenated. Subsequently, the reaction of the resulting compounds 33 with acrylic acids. 4 takes place.

In general, the alkylation of free sugars with protected bromoalkanols 36 (or iodides, tosylates or triflates) is also suitable for building up the particularly preferred spacers with HO- (CH ₂ ) _{p 1} -OH groups (see Scheme 11).

Often, however, this form of alkylation is inappropriate, especially to sufficiently alkylate the secondary OH groups of the carbohydrates. The degree of difficulty continues to increase with the number of secondary OH groups to be alkylated. For some applications, such as those in the prior art ( JP 2005 283 632 ) alkylation of 4,6-O-ethylidene-α-D-glucopyranose, it may be sufficient to obtain a mixture of differently alkylated building blocks. However, for the applications described here for LC display applications, it is necessary to be able to produce high-purity individual compounds in order to produce well-defined mixtures. For this, the method described above appears unsuitable. In particular, the presence of many OH groups in the "free" sugars often prevents a synthetically sufficient manipulability in the reaction media customary for organic reactions (solvents such as dichloromethane, ether, ethyl acetate, toluene, etc.). One starting point in sugar chemistry is therefore the protection, in many cases even first of all OH groups (see also deoxygenation at the anomeric center Scheme 30).

One way to achieve better reactivity towards alkylating agents such as alkyl bromides is to use glycosides (eg, alkyl glycosides such as compound 40) as the reactant. Such compounds are sufficiently reactive. Exhaustive alkylation of alkyl glycosides with alkyl bromides has been described in the literature [a) J. Slawomir, Bull. Pol. Ac. Sci. 1988, 36, 327-332. b) R. Nouguier, C. Medani, Tetrahedron Lett. 1987, 28, 319-320. c) M. Goebel, I. Ugi, Synthesis 1991, 1095-1098.]. Glycosides are generally compounds which carry a substituent other than a free hydroxy function at the anomeric center. Alkyl glycosides are easily converted by reacting the sugars with alcohols Presence of acid obtained. It is an acetalization reaction. Many simple glycosides are commercially available.

Here, methyl glycoside 40 is then alkylated with protected bromoalkanols 36 (SG = protecting group) and sodium hydride as base. Then, the methyl glycoside 41 can now be cleaved acid catalysed again. Subsequently, the remaining OH function can be provided with the still protected spacer group. This can be done in the sense of an acetalization with compounds 43 or in the form of an alkylation with compounds 36a. Here is also the possibility to attach other spacers than at the other positions. Thus, e.g. a group with different spacer length q1 be attached. q1 denotes an integer between 1 and 24, preferably between 1 and 12. After deprotection, esterification to the preferred acrylates may take place.

The reaction sequence can be further simplified (see Scheme 13). Thus, for example, the spacer provided with a protective group can be introduced in the first step.

Further preferred functionalized and further functionalizable reaction partners for an acetalization reaction at the anomeric center are shown in Scheme 14.

Sugars contain different reactive hydroxy functions. In hexoses such as D - (+) - glucose (70) there are three different reactive alcohol groups (cf. ). A primary hydroxy function, secondary hydroxy functions and the anomeric hydroxyl function. The exceptional reactivity of the anomeric center has just been discussed.

With D - (+) - glucose (70) and other hexoses, in general, all the reactions presented above can be carried out, and corresponding compounds can be obtained in this way. This is shown again in Scheme 18 by two examples.

Again, the different reactivity of the hydroxy functions can be used again to introduce different spacers (chain length, type), especially when protecting groups are used. This is illustrated in Scheme 19 using an example.

The anomeric center can be protected as before as alkyl glycoside, or the desired spacer or precursor can be introduced directly (compounds 73, q1 is an integer between 1 and 24, preferably between 1 and 12). A distinction between the primary and the secondary OH groups then succeeds with the introduction of a trityl protecting group to compounds 74. Then, the secondary OH groups can be esterified, for example, with bromoalkanoic acids. The trityl protecting group in 75 is then removed and appropriate groups can be attached to the primary OH group. Again an esterification was chosen, this time with a ω-bromoalkanoic acid 2a with a different chain length s1. s1 is an integer between 1 and 24, preferably between 1 and 12. Finally, all polymerizable groups are introduced by reaction with acrylic acids 4 to give compounds 77.

The person skilled in the art can combine or supplement the starting materials, reagents and methods shown in a suitable manner and thus obtain a large number of possible compounds.

Another preferred reaction is the Wittig-Horner-Emmons reaction at the anomeric center with stabilized ylides. In this way, C-glycosides such as 134 can be obtained from which spacer groups can be built. An example is shown in Scheme 32.

At this point we will again discuss further preferred spacer groups and their synthesis. The previous examples have shown compounds having extended OH groups of the formula -Sp "-OH units and the analogous bromides having -Sp" -Br units (where Sp "each represents a 1-oxa-alkylene chain having 2 or more C atoms) are important intermediates (eg compounds 9, 15), to which further groups can be attached.

Compounds such as 9 can, for example, in turn be reacted with ω-bromoalkanoic acids 2 or ω-bromoalkanoic acid chlorides 6 (see Scheme 33).

In this or similar way, more complex spacers can be built up or chains extended. The skilled person can combine suitable methods with each other. This also includes the alkylation with α-bromomethylacetates 137 and the reaction of bromides with, for example, (poly) ethylene glycols 141.

The products of the alkylation with α-bromomethylacetates 137 can be saponified and acrylate groups can be attached, e.g. directly via the esterification with (2-hydroxyalkylene) acrylates 47.

The products of the reaction with (poly) ethylene glycols 141 can be converted directly into acrylates.

Reaction with ethylene glycols 141.

The alkylation with α-bromomethylacetates 137 is also suitable for the all-round cultivation of preferred spacer groups Sp'X = OCH ₂ C (O) O (CH ₂ ) ₂ -, for example starting from glycosides such as 144 (compare Scheme 35).

Thus, generally described herein is a process for preparing compounds by derivatizing monosaccharides, in particular the above-mentioned or illustrated saccharides and their derivatives.

Further described herein is the use of the compounds in liquid crystalline media, especially the use as a polymer in such media. The compounds are also used as a polymer for stabilizing liquid-crystalline phases, in particular blue phases. This type of use is known and described in the case of the blue phases in the cited literature and in the examples section. In general, the medium is polymerized at a temperature at which it is in the blue phase. As a result, the stability range of this phase widens considerably.

Preferred liquid-crystalline media are characterized in that, after stabilization of the blue phase by polymerization, they are at least in the range from 15 to 30 ° C., preferably from 10 to 40 ° C., more preferably from 0 to 50 ° C., very preferably from -10 to 60 ° C have a blue phase.

An object of the present invention are liquid-crystalline media which contain a polymer of at least one monomer component selected from the formulas IA-1 to IA-10, or which comprises at least one unpolymerized monomer selected from the formulas IA-1 to IA-10 contain, or both.

Particularly preferred media according to the invention are mentioned below:

The medium contains one or more monoreactive monomers or a polymer which is made up of one or more monoreactive monomers and optionally further monomers. The proportion of Mono-reactive monomers is preferably 1 to 15%, more preferably 2 to 12%. Preferred monoreactive monomers are those of the formula I * as indicated below, in which the individual groups particularly preferably adopt the embodiments preferred for formula I * and only the radical R ^{a is} polymerizable. Particular preference is given to compounds of the formula I * in which n = 1 and B ¹ / B ^{2 is} cyclohexane-1,4-diyl or 1,4-phenylene.

In addition to the aforementioned monoreactive monomers, the medium contains one or more cross-linker compounds which are distinguished by a plurality of reactive groups. These include the compounds of formulas IA-1 to IA-10.

The medium contains one or more di-reactive monomers or a polymer composed of one or more di-reactive monomers and optionally further monomers. The proportion of di-reactive monomers is preferably 0 to 9%, more preferably 0 to 5%. In a preferred embodiment, the di-reactive monomers are wholly or partly replaced by the compounds of formulas IA-1 to IA-10 having 3 or more reactive groups.

The sum of mono- and di-reactive monomers is preferably 3 to 17%, more preferably 6-14%.

It is also possible to use triple or multiple (> 3) reactive monomers. The three or more (> 3) reactive monomers are preferably part or all of the compounds of formulas IA-1 to IA-10.

The ratio of monoreactive monomers to crosslinkers is preferably between 3: 1 and 1: 1. The ratio depends on the number of reactive groups of the crosslinkers involved. It is particularly preferred when using quadruple-reactive crosslinkers between 3: 1 and 2: 1, with the use of di-reactive crosslinkers particularly preferably between 1.5: 1 and 1: 1.

P

eine polymerisierbare Gruppe,

Sp

eine Abstandsgruppe oder eine Einfachbindung, und

R^a

einen organischen Rest mit mindestens 3 C-Atomen bedeutet.

For example, monoreactive monomers have a structure of the formula R ^a -Sp-P
wherein

P

a polymerizable group,

sp

a spacer group or a single bond, and

R ^a

an organic radical having at least 3 carbon atoms.

The radical R ^a may be a so-called mesogenic radical, which usually contains one or more rings, or a simple, usually chain-like, non-mesogenic radical.

Non-mesogenic radicals are preferably straight-chain or branched alkyl having 1 to 30 C atoms, in which one or more non-adjacent CH ₂ groups are each independently denoted by -C (R ⁰ ) = C (R ⁰⁰ ) -, -C≡ C, -N (R ⁰⁰ ) -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced so that and / or S atoms are not directly linked to one another, and in which also one or more H atoms can be replaced by F, Cl, Br, I or CN.

Preferred meanings of P and Sp correspond to the meanings given below for formula I *.

R^a und R^b

jeweils unabhängig voneinander P, P-Sp-, H, Halogen, SF₅, NO₂, eine Kohlenstoffgruppe oder Kohlenwasserstoffgruppe, wobei mindestens einer der Reste R^a und R^b eine Gruppe P oder P-Sp- bedeutet oder enthält,

P

bei jedem Auftreten gleich oder verschieden eine polymerisierbare Gruppe,

Sp

bei jedem Auftreten gleich oder verschieden eine Abstandsgruppe oder eine Einfachbindung,

B¹ und B²

jeweils unabhängig voneinander eine aromatische, heteroaromatische, alicyclische oder heterocyclische Gruppe, vorzugsweise mit 4 bis 25 Ringatomen, welche auch anellierte Ringe enthalten kann, und welche auch durch L ein- oder mehrfach substituiert sein kann,

L

P-Sp-, H, OH, CH₂OH, Halogen, SF₅, NO₂, eine Kohlenstoffgruppe oder Kohlenwasserstoffgruppe,

Z^b

bei jedem Auftreten gleich oder verschieden -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH₂-, -CH₂O-, -SCH₂-, -CH₂S-, -CF2O-, -OCF₂-, -CF2S-, -SCF₂-, -(CH₂)_n1-, -CF2CH2-,

R⁰ und R⁰⁰

-CH2CF2-, -(CF₂)_n1-, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR⁰R⁰⁰ oder eine Einfachbindung, jeweils unabhängig voneinander H oder Alkyl mit 1 bis 12 C-Atomen,

m

0, 1, 2, 3 oder 4,

n1

1, 2, 3 oder 4.

Preferred mesogenic monomers having one, two or more polymerisable groups are characterized by the formula I * R ^a -B ¹ - (Z ^b -B ² ) _m -R ^b I * wherein the individual radicals have the following meaning

R ^a and R ^b

each independently of one another P, P-Sp-, H, halogen, SF ₅ , NO ₂ , a carbon group or a hydrocarbon group, where at least one of the radicals R ^a and R ^b denotes or contains a group P or P-Sp-,

P

each time the same or different polymerizable group,

sp

the same or different for each occurrence, a spacer group or a single bond,

B ¹ and B ²

each independently of one another an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, and which may also be monosubstituted or polysubstituted by L,

L

P-Sp-, H, OH, CH ₂ OH, halogen, SF ₅ , NO ₂ , a carbon group or hydrocarbon group,

Z ^b

the same or different at each occurrence -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH ₂ -, -CH ₂ O-, SCH ₂ -, -CH ₂ S-, -CF 2 O-, -OCF ₂ -, -CF2S-, -SCF ₂ -, - (CH _{2) n1} -, -CF2CH2-,

R ⁰ and R ⁰⁰

-CH2CF2-, - (CF _{2) n1} -, -CH = CH-, -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH-, CR ⁰ R ⁰⁰ or a single bond, in each case independently of one another H or alkyl having 1 to 12 C atoms,

m

0, 1, 2, 3 or 4,

n1

1, 2, 3 or 4.

R^a und R^b

jeweils unabhängig voneinander P, P-Sp-, H, F, Cl, Br, I, -CN, -NO₂, -NCO, -NCS, -OCN, -SCN, SF₅ oder geradkettiges oder verzweigtes Alkyl mit 1 bis 25 C-Atomen, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander durch -C(R⁰)=C(R⁰⁰)-, -C≡C-, -N(R⁰⁰)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- so ersetzt sein können, dass O- und/oder S-Atome nicht direkt miteinander verknüpft sind, und worin auch ein oder mehrere H-Atome durch F, Cl, Br, I, CN, P oder P-Sp- ersetzt sein können, wobei mindestens einer der Reste R^a und R^b eine Gruppe P oder P-Sp- bedeutet oder enthält

B¹ und B²

jeweils unabhängig voneinander 1,4-Phenylen, Naphthalin-1,4-diyl, Naphthalin-2,6-diyl, Phenanthren-2,7-diyl, Anthracen-2,7-diyl, Fluoren-2,7-diyl, Cumarin, Flavon, wobei in diesen Gruppen auch eine oder mehrere CH-Gruppen durch N ersetzt sein können, Cyclohexan-1,4-diyl, worin auch eine oder mehrere nicht-benachbarte CH₂-Gruppen durch O und/oder S ersetzt sein können, 1,4-Cyclohexenylen, Bicyclo[1.1.1]pentan-1,3-diyl, Bicyclo[2.2.2]octan-1,4-diyl, Spiro[3.3]heptan-2,6-diyl, Piperidin-1,4-diyl, Decahydronaphthalin-2,6-diyl, 1,2,3,4-Tetrahydronaphthalin-2,6-diyl, Indan-2,5-diyl oder Octahydro-4,7-methano-indan-2,5-diyl, wobei alle diese Gruppen unsubstituiert oder durch L ein- oder mehrfach substituiert sein können,

L

P, P-Sp-, OH, CH₂OH, F, Cl, Br, I, -CN, -NO₂, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R^x)2, -C(=O)Y¹, -C(=O)R^x, -N(R^x)₂, optional substituiertes Silyl, optional substituiertes Aryl mit 6 bis 20 C Atomen, oder geradkettiges oder verzweigtes Alkyl, Alkoxy, Alkylcarbonyl, Alkoxycarbonyl, Alkylcarbonlyoxy oder Alkoxycarbonyloxy mit 1 bis 25 C-Atomen, worin auch ein oder mehrere H-Atome durch F, Cl, P oder P-Sp- ersetzt sein können,

P und Sp

die oben angegebene Bedeutung,

Y¹

Halogen,

R^x

P, P-Sp-, H, Halogen, geradkettiges, verzweigtes oder cyclisches Alkyl mit 1 bis 25 C-Atomen, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen durch -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- so ersetzt sein können, dass O- und/oder S-Atome nicht direkt miteinander verknüpft sind, und worin auch ein oder mehrere H-Atome durch F, Cl, P oder P-Sp- ersetzt sein können, eine optional substituierte Aryl- oder Aryloxygruppe mit 6 bis 40 C-Atomen, oder eine optional substituierte Heteroaryl- oder Heteroaryloxygruppe mit 2 bis 40 C-Atomen,

und/oder

m

0, 1 oder 2.

Particularly preferred compounds of the formula I * are those in which optionally one or more of the radicals is

R ^a and R ^b

each independently of one another P, P-Sp, H, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, SF ₅ or straight-chain or branched alkyl having 1 to 25 C atoms in which one or more non-adjacent CH ₂ groups are each independently denoted by -C (R ⁰ ) = C (R ⁰⁰ ) -, -C≡C-, -N (R ⁰⁰ ) -, -O- , -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- can be replaced so that O and / or S atoms are not directly linked to one another, and in which one or more H atoms can also be replaced by F, Cl, Br, I, CN, P or P-Sp-, where at least one of the radicals R ^a and R ^b denotes or contains a group P or P-Sp-

B ¹ and B ²

each independently of one another 1,4-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthren-2,7-diyl, anthracene-2,7-diyl, fluorene-2,7-diyl, coumarin , Flavone, where in these groups one or more CH groups may be replaced by N, cyclohexane-1,4-diyl, in which also one or more non-adjacent CH ₂ groups may be replaced by O and / or S, 1,4-cyclohexenylene, bicyclo [1.1.1] pentane-1,3-diyl, bicyclo [2.2.2] octane-1,4-diyl, spiro [3.3] heptane-2,6-diyl, piperidine-1, 4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indan-2,5-diyl or octahydro-4,7-methano-indan-2,5- diyl, where all of these groups may be unsubstituted or monosubstituted or polysubstituted by L,

L

P, P-Sp-, OH, CH ₂ OH, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C (= O) N (R ^x ) 2, -C (= O) Y ¹ , -C (= O) R ^x , -N (R ^x ) ₂ , optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms, or straight or branched alkyl, alkoxy , Alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, in which also one or more H atoms may be replaced by F, Cl, P or P-Sp-,

P and Sp

the meaning given above,

Y ¹

Halogen,

^Rx

P, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which also one or more non-adjacent CH ₂ groups is represented by -O-, -S-, -CO-, - CO-O-, -O-CO-, -O-CO-O- can be replaced so that O and / or S atoms are not directly linked to one another, and in which also one or more H atoms are represented by F, Cl, P or P-Sp- may be replaced, an optionally substituted aryl or aryloxy group having 6 to 40 carbon atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 carbon atoms,

and or

m

0, 1 or 2.

The term "carbon group" means a monovalent or polyvalent organic group containing at least one carbon atom, which either contains no further atoms (such as -C≡C-), or optionally one or more further atoms such as N, O, S, Contains P, Si, Se, As, Te or Ge (eg carbonyl, etc.). The term "hydrocarbon group" means a carbon group which additionally contains one or more H atoms and optionally one or more heteroatoms such as, for example, N, O, S, P, Si, Se, As, Te or Ge.

"Halogen" means F, Cl, Br or I, preferably F or Cl.

A carbon or hydrocarbon group may be a saturated or unsaturated group. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. A carbon or hydrocarbon radical having more than 3 C atoms may be straight-chain, branched and / or cyclic, and may also have spiro-linkages or fused rings.

The terms "alkyl", "aryl", "heteroaryl" etc. also include polyvalent groups, for example alkylene, arylene, heteroarylene, etc.

The term "aryl" means an aromatic carbon group or a group derived therefrom. The term "heteroaryl" means "aryl" as defined above containing one or more heteroatoms.

Preferred carbon and hydrocarbon groups are optionally substituted alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having from 1 to 40, preferably 1 to 25, more preferably 1 to 18 carbon atoms, optionally substituted aryl or aryloxy having 6 to 40, preferably 6 to 25 C-atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 6 to 40, preferably 6 to 25 C-atoms.

Further preferred carbon and hydrocarbon groups are C ₁ -C ₄₀ alkyl, C ₂ -C ₄₀ alkenyl, C ₂ -C ₄₀ alkynyl, C ₃ -C ₄₀ allyl, C ₄ -C ₄₀ alkyl dienyl, C ₄ -C ₄₀ polyenyl, C ₆ -C ₄₀ aryl, C ₆ -C ₄₀ alkylaryl, C ₆ -C ₄₀ arylalkyl, C ₆ -C ₄₀ alkylaryloxy, C ₆ -C ₄₀ arylalkyloxy, C ₂ -C ₄₀ heteroaryl, C ₄ -C ₄₀ cycloalkyl, C ₄ -C ₄₀ cycloalkenyl, etc. Particularly preferred are C ₁ -C ₂₂ alkyl, C ₂ -C ₂₂ alkenyl, C ₂ -C ₂₂ alkynyl, C ₃ -C ₂₂ allyl, C ₄ -C ₂₂ alkyl dienyl, C ₆ -C ₁₂ Aryl, C ₆ -C ₂₀ arylalkyl and C ₂ -C ₂₀ heteroaryl.

Further preferred carbon and hydrocarbon groups are straight-chain, branched or cyclic alkyl radicals having 1 to 40, preferably 1 to 25, carbon atoms which are unsubstituted or monosubstituted or polysubstituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH ₂ groups each independently of one another by -C (R ^x ) = C (R ^x ) -, -C≡C-, -N (R ^x ) -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-may be replaced so that O and / or S atoms are not directly linked.

R ^x is preferably H, halogen, a straight-chain, branched or cyclic alkyl chain having 1 to 25 C atoms, in which one or more nonadjacent C atoms are represented by -O-, -S-, -CO-, -CO- O-, -O-CO-, -O-CO-O- may be replaced, wherein also one or more H atoms may be replaced by fluorine, an optionally substituted aryl or aryloxy group having 6 to 40 carbon atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 carbon atoms.

Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n- Heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

Examples of preferred alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2- Ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, Perfluorohexyl etc.

Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.

Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n- Heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.

Aryl and heteroaryl groups can be mononuclear or polynuclear, i. they may have a ring (such as phenyl) or two or more rings, which may also be fused (such as naphthyl) or covalently linked (such as biphenyl), or a combination of fused and linked rings. Heteroaryl groups contain one or more heteroatoms, preferably selected from O, N, S and Se.

Particularly preferred are mono-, di- or trinuclear aryl groups having 6 to 25 carbon atoms and mono-, di- or trinuclear heteroaryl groups having 2 to 25 carbon atoms, which optionally contain fused rings and are optionally substituted. Also preferred are 5-, 6- or 7-membered aryl and heteroaryl groups, wherein also one or more CH groups can be replaced by N, S or O so that O atoms and / or S atoms do not directly link with each other are.

Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1 ': 3', 1 "] terphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzpyrene , Fluorene, indene, indenofluorene, spirobifluorene, etc.

Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1 , 3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4 Thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1, 2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, or condensed groups such as indole, isoindole, indolizine, indazole, benzimidazole, Benzotriazole, purine, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazine imidazole, quinoxaline imidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6, 7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, Quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno [2,3b] thiophene, thieno [3,2b] thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazothiophene, or combinations of these groups. The heteroaryl groups may also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or other aryl or heteroaryl groups.

The (non-aromatic) alicyclic and heterocyclic groups include both saturated rings, i. those containing only single bonds as well as partially unsaturated rings, i. those which may also contain multiple bonds. Heterocyclic rings contain one or more heteroatoms, preferably selected from Si, O, N, S and Se.

The (non-aromatic) alicyclic and heterocyclic groups can be mononuclear, ie contain only one ring (such as cyclohexane), or be polynuclear, ie contain several rings (such as decahydronaphthalene or bicyclooctane). Particularly preferred are saturated groups. Also preferred are mono-, di- or trinuclear groups having 3 to 25 carbon atoms, which optionally contain fused rings and are optionally substituted. Also preferred are 5-, 6-, 7- or 8-membered carbocyclic groups wherein also one or more carbon atoms may be replaced by Si and / or one or more CH groups may be replaced by N and / or one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-.

Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, pyrrolidine, 6-membered groups such as cyclohexane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine, 7-membered Groups such as cycloheptane, and fused groups such as tetrahydronaphthalene, decahydronaphthalene, indane, bicyclo [1.1.1] pentane-1,3-diyl, bicyclo [2.2.2] octane-1,4-diyl, spiro [3.3] heptane-2, 6-diyl, octahydro-4,7-methano-indan-2,5-diyl.

Preferred substituents are, for example, solubility-promoting groups such as alkyl or alkoxy, electron-withdrawing groups such as fluorine, nitro or nitrile, or substituents for increasing the Glass transition temperature (Tg) in the polymer, especially bulky groups such as tert-butyl or optionally substituted aryl groups.

Preferred substituents, also referred to below as "L", are, for example, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C (= O) N (R ^x ) ₂ , -C (= O) Y ¹ , -C (= O) R ^x , -N (R ^x ) ₂ , wherein R ^{x has} the meaning indicated above and Y ^{1 is} halogen, optionally substituted silyl or Aryl having 6 to 40, preferably 6 to 20 C atoms, and straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 carbon atoms, wherein one or more H atoms are optionally replaced by F or Cl can.

"Substituted silyl or aryl" is preferably substituted by halogen, -CN, R ⁰ , -OR ⁰ , -CO-R ⁰ , -CO-OR ⁰ , -O-CO-R ⁰ or -O-CO-OR ⁰ , wherein R ^{0 has} the meaning given above.

ist vorzugsweise

worin L eine der oben angegebenen Bedeutungen hat.Particularly preferred substituents L are, for example F, Cl, CN, NO _2, CH 3, C ₂ H _5, OCH 3, OC ₂ H _5, COCH _3, COC2H5, COOCH _3, COOC ₂ H _5, CF 3, OCF _3, OCHF _2, OC ₂ F ₅ , furthermore phenyl.

is preferable

wherein L has one of the meanings given above.

The polymerizable group P is a group suitable for a polymerization reaction such as radical or ionic chain polymerization, polyaddition or polycondensation, or for a polymer-analogous reaction, for example, addition or condensation to a polymer main chain. Particular preference is given to groups for chain polymerization, in particular those containing a C =C double bond or C≡C triple bond, and groups suitable for polymerization with ring opening, for example oxetane or epoxy groups

Preferred groups P are defined as for the formulas IA-1 to IA-10 above.

Preferred spacer groups Sp are selected from the formula Sp'-X- as defined above for the formulas IA-1 to IA-10.

alkyl

eine Einfachbindung oder geradkettiges oder verzweigtes Alkylen mit 1 bis 12 C-Atomen bedeutet, worin eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander durch -C(R⁰⁰)=C(R⁰⁰⁰)-, -C≡C-, -N(R⁰⁰)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- so ersetzt sein können, dass O- und/oder S-Atome nicht direkt miteinander verknüpft sind, und worin auch ein oder mehrere H-Atome durch F, Cl oder CN ersetzt sein können, wobei R⁰⁰ und R⁰⁰⁰ die oben angegebene Bedeutung haben,

aa und bb

jeweils unabhängig voneinander 0, 1, 2, 3, 4, 5 oder 6 bedeuten,

und

P^1-5

jeweils unabhängig voneinander eine der für P angegebenen Bedeutungen besitzen.

In a further preferred embodiment of the invention, P-Sp- is a radical having two or more polymerisable groups (multifunctional polymerizable radicals). Suitable radicals of this type, as well as polymerizable compounds containing them and their preparation are, for example, in US Pat. No. 7,060,200 B1 or US 2006/0172090 A1 described. Particularly preferred are multifunctional polymerizable radicals P-Sp- selected from the following formulas -X-alkyl-CHP ¹ -CH ₂ -CH ₂ P ² I * a -X-alkyl-C (CH ₂ P ¹ ) (CH ₂ P ² ) -CH ₂ P ³ I * b -X-alkyl-CHP ¹ CHP ² -CH ₂ P ³ I * c -X-alkyl-C (CH ₂ P ¹ ) (CH ₂ P ² ) -C _aa H _{2aa + 1} I * d -X-alkyl-CHP ¹ -CH ₂ P ² I * e -X-alkyl-CHP ¹ P ² I * f - X-alkyl-CP ¹ P ² -C _aa H _{2aa + 1} I * g -X-alkyl-C (CH ₂ P ¹ ) (CH ₂ P ² ) -CH ₂ OCH ₂ -C (CH ₂ P ³ ) (CH ₂ P ⁴ ) CH ₂ P ⁵ I * h -X-alkyl-CH ((CH ₂ ) aaP ¹ ) ((CH ₂ ) _bbP ² ) I * i ^-X-alkyl-1 CHP CHP ² -C _aa H _{2aa + 1} I * k -X-alkyl-C (CH ₃ ) (CH ₂ P ¹ ) (CH ₂ P ² ) I * m wherein

alkyl

is a single bond or straight-chain or branched alkylene having 1 to 12 C atoms, in which one or more nonadjacent CH ₂ groups are each independently denoted by -C (R ⁰⁰ ) = C (R ⁰⁰⁰ ) -, -C≡C-, -N (R ⁰⁰ ) -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced so that O- and / or S atoms are not directly linked to one another, and in which also one or more H atoms can be replaced by F, Cl or CN, where R ⁰⁰ and R ^{000 have} the abovementioned meaning,

aa and bb

each independently of one another denote 0, 1, 2, 3, 4, 5 or 6,

and

P ^1-5

each independently of one another have one of the meanings given for P.

The polymerisable compounds and RMs can be prepared analogously to those known to those skilled in the art and described in standard works of organic chemistry, such as in Houben-Weyl, Methods of Organic Chemistry, Thieme Verlag, Stuttgart. Other synthetic methods can be found in the documents cited above and below. In the simplest case, the synthesis of such RMs takes place, for example, by esterification or etherification of 2,6-dihydroxynaphthalene or 4,4'-dihydroxybiphenyl with corresponding acids, acid derivatives or halogenated compounds containing a group P, such as, for example, (meth) acryloyl chloride or ( Meth) acrylic acid, in the presence of a dehydrating reagent such as DCC (dicyclohexylcarbodiimide).

As a further component, the liquid-crystalline media preferably contain the liquid-crystalline phase-supporting, non-polymerizable compounds, which is also referred to as a host mixture. This proportion is typically 50 to 95 wt .-%, preferably 80 to 90 wt .-%. In the case of polymer-stabilized blue phases, the non-polymerizable fraction preferably comprises compounds selected from Table A (see example part). Preferably, the proportion to 50 wt .-% or more of these compounds, most preferably 80 wt .-% or more.

The blue-crystalline liquid-crystalline media according to the invention preferably have a positive dielectric anisotropy. They can be designed to have very high dielectric anisotropy combined with high optical anisotropies.

worin

R¹

jeweils unabhängig voneinander einen unsubstituierten Alkylrest mit 1 bis 15 C-Atomen, wobei in diesem Rest auch eine oder mehrere CH₂-Gruppen jeweils unabhängig voneinander durch -C≡C-, -CH=CH-, -CF=CF-, -CF=CH-, -CH=CF-, -(CO)O-, -O(CO)-, -(CO)- oder -O- so ersetzt sein können, dass O-Atome nicht direkt miteinander verknüpft sind, bevorzugt einen geradkettigen Alkylrest mit 2 bis 7 C-Atomen,

A², A³

unabhängig voneinander

Z², Z³

unabhängig voneinander eine Einfachbindung, CF₂O, CH₂CH₂, CF₂CH₂, CF₂CF₂, CFHCFH, CFHCH₂, (CO)O, CH₂O, C≡C, CH=CH, CF=CH, CF=CF; wobei unsymmetrische Bindeglieder (z.B. CF₂O) in beide möglichen Richtungen orientiert sein können,

X¹

F, Cl, CN, oder Alkyl, Alkenyl, Alkenyloxy, Alkylalkoxy oder Alkoxy mit 1 bis 3 C-Atomen, welches durch F ein- oder mehrfach substituiert ist, und

L¹ bis L⁴

H oder F,

bedeuten.Preferred further compounds for the liquid-crystalline media according to the invention are selected from the compounds of the formula II and III:

wherein

R ¹

in each case independently of one another an unsubstituted alkyl radical having 1 to 15 C atoms, wherein in this radical also one or more CH ₂ groups each independently of one another by -C≡C-, -CH = CH-, -CF = CF-, -CF = CH-, -CH = CF-, - (CO) O-, -O (CO) -, - (CO) - or -O- can be replaced so that O atoms are not directly linked, preferably one straight-chain alkyl radical having 2 to 7 C atoms,

A ² , A ³

independently of each other

Z ² , Z ³

independently of each other a single bond, CF ₂ O, CH ₂ CH ₂ , CF ₂ CH ₂ , CF ₂ CF ₂ , CFHCFH, CFHCH ₂ , (CO) O, CH ₂ O, C≡C, CH = CH, CF = CH, CF = CF; unsymmetrical linkers (eg CF ₂ O) may be oriented in both possible directions,

X ¹

F, Cl, CN, or alkyl, alkenyl, alkenyloxy, alkylalkoxy or alkoxy having 1 to 3 C atoms, which is mono- or polysubstituted by F, and

L ¹ to L ⁴

H or F,

mean.

The liquid-crystalline media preferably contain between 20 and 40% by weight of compounds of the formula II. The compounds of the formula III are preferably used, if present, with up to 20% by weight. The remaining other compounds, if present, are selected from further compounds with high dielectric anisotropy, high optical anisotropy and preferably with a high clearing point.

worin R¹ und L¹ wie für Formel II definiert sind.Preferred compounds of the formula II are those of the formula IIa:

wherein R ¹ and L ^{1 are} as defined for formula II.

worin R¹ wie für Formel III definiert ist.Preferred compounds of the formula III are those of the formula IIIa or IIIb:

wherein R ^{1 is} as defined for formula III.

The preparation of the FK media which can be used according to the invention is carried out in a conventional manner, for example by mixing one or more of the abovementioned compounds with one or more polymerizable compounds as defined above and, if appropriate, with further liquid-crystalline compounds and / or additives. In general, the desired amount of the components used in lesser amount is dissolved in the constituent of the main component, expediently at elevated temperature. It is also possible solutions of the components in an organic solvent, e.g. in acetone, chloroform or methanol, and to remove the solvent again after thorough mixing, for example by distillation. The process for producing the LC media according to the invention is a further subject of the invention.

It goes without saying for the person skilled in the art that the LC media according to the invention can also contain compounds in which, for example, H, N, O, Cl, F have been replaced by the corresponding isotopes.

In the context of the present invention, the terms alkyl, alkenyl, etc. are defined as follows:

The term "alkyl" embraces straight-chain and branched alkyl groups having 1-9 carbon atoms, in particular the straight-chain groups methyl, ethyl, propyl, butyl, pentyl, hexyl and heptyl. Groups of 2-5 carbon atoms are generally preferred.

The term "alkenyl" includes straight-chain and branched alkenyl groups having up to 9 carbon atoms, especially the straight-chain groups. Particularly preferred alkenyl groups are C ₂ -C ₇ -1E-alkenyl, C ₄ -C ₇ -E-alkenyl, C ₅ -C ₇ -alkenyl, C ₆ -C ₇ -5-alkenyl and C ₇ -6-alkenyl , in particular C ₂ -C ₇ -1E-alkenyl, C ₄ -C ₇ 3E-alkenyl and C ₅ -C ₇ -4-alkenyl. Examples of preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Groups of up to 5 carbon atoms are generally preferred.

The term "fluoroalkyl" in this application includes straight-chain groups having at least one fluorine atom, preferably a terminal fluorine, i. Fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. Other positions of the fluorine are not excluded.

The term "halogenated alkyl" preferably includes mono- or polyfluorinated and / or chlorinated radicals. Perhalogenated radicals are included. Particularly preferred are fluorinated alkyl radicals, in particular CF ₃ , CH ₂ CF ₃ , CH ₂ CHF ₂ , CHF ₂ , CH ₂ F, CHFCF ₃ and CF ₂ CHFCF ₃ .

The term "alkylene" embraces straight-chain and branched alkanediyl groups having 1-12 carbon atoms, in particular the straight-chain groups methylene, ethylene, propylene, butylene and pentylene. Groups of 2-8 carbon atoms are generally preferred.

Further combinations of the embodiments and variants of the invention according to the description will become apparent from the claims.

Used abbreviations: DCC dicyclohexylcarbodiimide DMAP 4- (dimethylamino) pyridine, 9-BBN 9-borabicyclo [3.3.1] nonane, MTBE Methyl tert-butyl ether, DMSO Dimethyl sulfoxide.

• Designations of the phase ranges:
  • K: crystalline; N: nematic; BP: blue phase; Tg: glass transition temperature; I: isotropic.

Examples

Reference Example 1: 5- (2-Methyl-acryloyloxy) -valeric acid (3R, 4S, 5R) -4,5,6-tris [5- (2-methyl-acryloyloxy) -pentanoyloxy] -tetrahydropyran-3-yl ester

The compound becomes 5- (2-methyl-acryloyloxy) valeric acid (3R, 4S, 5R) -4,5,6-tris [5- (2-methyl-acryloyloxy) -pentanoyloxy] -tetrahydropyran-3-yl ester synthesized as described below.

1.1 Esterification of D - (+) - xylose with bromovaleric acid: Preparation of 5-bromovaleric acid (3R, 4S, 5R) -4,5,6-tris (5-bromo-pentanoyloxy) -tetrahydropyran-3-yl ester

20.0 g (0.13 mol) of D - (+) - xylose are initially charged together with 120.0 g (0.67 mol) of 5-bromovaleric acid and 1.0 g (8.19 mmol) of DMAP in 1500 ml of dichloromethane , A solution of 140.0 g (0.68 mol) of DCC in 500 ml of dichloromethane is metered in, and the mixture is stirred for 72 h at room temperature. 50.0 g (0.40 mol) of oxalic acid dihydrate are added and after 1 h is filtered off from the insoluble. The filtrate is completely concentrated and the residue is purified by column chromatography (SiO ₂ , dichloromethane: MTBE = 97: 3).

1.2 Preparation of 5- (2-methyl-acryloyloxy) valeric acid (3R, 4S, 5R) -4,5,6-tris [5- (2-methyl-acryloyloxy) -pentanoyloxy] -tetrahydropyran-3-yl ester

3.5 g (4.36 mmol) of 5-bromovaleric acid (3R, 4S, 5R) -4,5,6-tris (5-bromopentanoyloxy) -tetrahydropyran-3-yl ester are added together with 4.4 ml (52.0 mmol) of methacrylic acid and 8.44 g (61.1 mmol) of potassium carbonate in 50 ml of DMSO at 50 ° C. The suspension is diluted with MTBE and washed with water. The aqueous phase is extracted with MTBE and the combined organic phases are washed with saturated sodium chloride solution. The solution is dried with sodium sulfate and completely concentrated. The residue is purified by column chromatography (SiO ₂ , dichloromethane: MTBE = 95: 5). To this To give 5- (2-methyl-acryloyloxy) -valeric acid (3R, 4S, 5R) -4,5,6-tris [5- (2-methyl-acryloyloxy) -pentanoyloxy] -tetrahydropyran-3-yl ester ( α: β ≈ 88:12) as a colorless oil.

Phase sequence: Tg -62 I

¹ H-NMR (300 MHz, CHCl ₃ ): δ = 6.29 (d, 1H, J = 3.7 Hz, H _pyranyl ), 6.11-6.07 (m, 4H, H _acrylate ), 5 , 57-5.54 (m, 4H, H _acrylate ), 5.47 (t, 1H, J = 9.8 Hz, H _pyranyl ), 5.10-5.02 (m, 2H, H _pyranyl ), 4.20-4.10 (m, 8H, 4 x CH ₂ OC (O)), 3.94 (dd, 1H, J = _11.3Hz , J = _5.9Hz , H _pyranyl ), 3 , 69 (t, 1H, J = 11.3 Hz, H _pyranyl ), 2.52-2.23 (m, 8H, 4 × OC (O) CH ₂ ), 1.95-1.93 (m, 12H, 4 × CMe = CH ₂ ), 1.79-1.63 (m, 16H, H _aliphate ).
(Given are the data for the main anomer)

MS (EI): m / z (%) = 822 (1, M ⁺ ), 69 (100).

Reference Example 2: 5-Acryloyloxy-valeric acid (3R, 4S, 5R) -4,5,6-tris (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester

The compound 5-acryloyloxy-valeric acid (3R, 4S, 5R) -4,5,6-tris (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester is synthesized as described below.

2.1 Preparation of 5-acryloyloxy-valeric acid (3R, 4S, 5R) -4,5,6-tris (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester

17.0 g (17.3 mmol) of 5-bromovaleric acid (3R, 4S, 5R) -4,5,6-tris (5-bromopentanoyloxy) -tetrahydropyran-3-yl ester are added together with 14.3 ml (0 , 21 mol) of acrylic acid and 33.5 g (0.24 mol) of potassium carbonate in 500 ml of DMSO at 50 ° C. The suspension is diluted with MTBE and washed with water. The aqueous phase is extracted with MTBE and the combined organic phases are washed with saturated sodium chloride solution. The solution is dried with sodium sulfate and completely concentrated. The residue is purified by column chromatography (SiO ₂ , dichloromethane: MTBE = 95: 5 and SiO ₂ , pentane: MTBE = 6: 4). In this way, 5-acryloyloxy-valeric acid (3R, 4S, 5R) -4,5,6-tris (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester (α: β ≈ 92: 8) is obtained as a colorless oil receive.

Phase sequence: Tg -57 I

¹ H-NMR (300 MHz, CHCl ₃ ): δ = 6.40 (dm, 4H, J = 17.4 Hz, H _acrylic ), 6.29 (d, 1H, J = 3.8 Hz, H _pyranyl ), 6.17-6.06 (m, 4H, H _acrylic ), 5.83 (dm, 4H, J = 10.4Hz, H _acrylic .), 5.47 (t, 1H, J = 9, 8 Hz, H _pyranyl ), 5.10-5.00 (m, 2H, H _pyranyl ), 4.22-4.10 (m, 8 H, 4 x CH ₂ OC (O)), 3.94 ( dd, 1H, J = 11.3 Hz, J = 5.9 Hz, H _pyranyl ), 3.70 (t, 1H, J = 11.3 Hz, H _pyranyl ), 2.52-2.24 (m , 8H, 4 × OC (O) CH ₂ ), 1.79-1.63 (m, 16H, H _aliphate ).
(Given are the data for the main anomer)

Reference Example 3: 5-Acryloyloxy-valeric acid (3R, 4S) -4,6-bis (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester

The compound 5-acryloyloxy-valeric acid (3R, 4S) -4,6-bis (5-acryloyloxypentanoyloxy) -tetrahydropyran-3-yl ester is synthesized as described below.

3.1 Esterification of 2-deoxy-D-ribose with bromovaleric acid: Preparation of 5-bromovaleric acid (3R, 4S) -4,6-bis (5-bromopentanoyloxy) -tetrahydropyran-3-yl ester

15.0 g (0.11 mol) of 2-deoxy-D-ribose are introduced together with 80.0 g (0.44 mol) of 5-bromovaleric acid and 1.0 g (8.19 mmol) of DMAP in 2000 ml of dichloromethane , A solution of 100.0 g (0.48 mol) of DCC in 500 ml of dichloromethane is metered in, and the mixture is stirred for 48 h at room temperature. An additional 20.0 g (0.11 mol) of 5-bromovaleric acid are added and the mixture is stirred again for 72 h. 50.0 g (0.40 mol) of oxalic acid dihydrate are added and after 1 h is filtered off from the insoluble. The filtrate is completely concentrated and the residue is purified by column chromatography (SiO ₂ , dichloromethane: MTBE = 97: 3 and Al ₂ O ₃ , dichloromethane: MTBE = 97: 3). 5-Bromovaleric acid (3R, 4S) -4,6-bis (5-bromo-pentanoyloxy) -tetrahydropyran-3-yl ester is obtained as a colorless oil.

3.2 Preparation of 5-acryloyloxy-valeric acid (3R, 4S) -4,6-bis (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester

15.0 g (24.1 mmol) of 5-acryloyloxy-valeric acid (3R, 4S) -4,6-bis (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester are added together with 15.0 ml (0, 22 mol) of acrylic acid and 37.0 g (0.27 mol) of potassium carbonate in 500 ml of DMSO for 24 h at 50 ° C stirred. The suspension is diluted with MTBE and washed with water. The aqueous phase is extracted with MTBE and the combined organic phases are washed with saturated sodium chloride solution. The solution is dried with sodium sulfate and completely concentrated. The residue is purified by column chromatography (SiO ₂ / Al ₂ O ₃ , dichloromethane: MTBE = 95: 5 and SiO ₂ , dichloromethane: MTBE = 9: 1). In this way, 5-acryloyloxy-valeric acid (3R, 4S) -4,6-bis (5-acryloyloxy-pentanoyloxy) -tetrahydropyran-3-yl ester (α □: β ≈ 99: 1) is obtained as a colorless oil.

Phase sequence: Tg -57 I

¹ H-NMR (400 MHz, CHCl ₃ ): δ = 6.41 (dd, 3H, J = 17.2 Hz, J = 1.6 Hz, H _acrylate ), 6.30-6.27 (m, 1H, H _pyranyl ), 6.12 (ddd, 3H, J = 17.2 Hz, J = 10.4 Hz, J = 1.6 Hz, H _acrylate ), 5.83 (dd, 3H, J = 10 , 4 Hz, J = 1.6 Hz, H _acrylate ), 5.36-5.30 (m, 1H, H _pyranyl ), 5.24 (s (broad), 1H, H _pyranyl ), 4.23- 4.14 (m, 6H, 3 x CH ₂ OC (O)), 4.01 (dd, 1H, J = 13.0 Hz, J = 1.6 Hz, H _pyranyl ), 3.86 (dd, 1H, J = _13.0Hz , J = _2.6Hz , H _pyranyl ), 2.48-2.40 (m, 4H, H _aliphate ), 2.36-2.29 (m, 2H, H _aliphatic ), 2.28-2.20 (m, 1H, H _pyranyl ), 1.92 (dm, 1H, J = 13.0 Hz, H _pyranyl ), 1.80-1.67 (m, 12H , H _aliphate ).

Reference Example 4: 2-Methacrylic acid (3R, 4S, 5S) -4,5,6-tris (2-methylacryloyloxy) -tetrahydropyran-3-yl ester

The compound 2-methacrylic acid (3R, 4S, 5S) -4,5,6-tris (2-methylacryloyloxy) -tetrahydropyran-3-yl ester is synthesized as described below.

5.0 g (33.3 mmol) of L - (+) - arabinose are initially charged together with 34.0 ml (0.4 mol) of methacrylic acid and 0.2 g (1.6 mmol) of DMAP in 300 ml of THF. A solution of 82.5 g (0.40 mol) of DCC in 200 ml of THF is metered in, and the mixture is stirred for 20 h at room temperature. 25.2 g (0.2 mol) of oxalic acid dihydrate are added, and after 1 h, the insolubles are filtered off. The filtrate is completely concentrated and the residue is purified by column chromatography (SiO ₂ , dichloromethane). 2-Methacrylic acid (3R, 4S, 5S) -4,5,6-tris (2-methyl-acryloyloxy) -tetrahydropyran-3-yl ester is obtained as anomeric mixture (α: β = 3: 1).

Phase sequence: Tg -21 I

The ¹ H and ¹³ C NMR spectroscopic data agree with the structure. $$\begin{array}{l}\mathbf{MS}\left(eI\right):\text{m / z}\left(\text{\%}\right)=422\left(\mathrm{1,}{\text{M}}^{+}\right).337\left(28\left[{\text{MH}}_2\text{C = CH}\left({\text{CH}}_3\right)-{\text{COO}}^{+}\right]\right)\mathrm{,\; 41}\\ \left(100\right),\end{array}$$

Reference Example 5: 2-Methacrylic acid-3 - {(3S, 4R, 5R) -2,3,5-tris [3- (2-methyl-acryloyloxy) -propoxy] tetra-hydropyran-4-yloxy} -propyl ester

The compound 2-methacrylic acid-3 - {(3S, 4R, 5R) -2,3,5-tris [3- (2-methyl-acryloyloxy) -propoxy] -tetra-hydropyran-4-yloxy} -propyl ester is synthesized as follows described.

5.1 Allylation of L - (+) - arabinose

100.0 g (2.50 mol) of NaH (60% suspension in mineral oil) are washed with pentane and suspended in 1700 ml of DMF. 62.5 g (0.42 mol) of L - (+) - arabinose are added in portions, and the mixture is stirred for 1 h in an ultrasonic bath. Thereafter, it is stirred for 1 h at room temperature. A solution of 220 ml (2.54 mol) of allyl bromide in 300 ml of DMF is added slowly and under countercooling so that the internal temperature does not exceed 27 ° C. After the addition is stirred for 22 h.

The mixture is mixed with ethanol and added to ice water. The mixture is extracted several times with MTBE and the combined organic phases are washed with sodium chloride solution. The solution is dried with sodium sulfate and completely concentrated. The crude product is purified by column chromatography (SiO ₂ , CH ₂ Cl ₂ → MTBE).

5.2 hydroboration / oxidation

15.0 g (48.3 mmol) of (3S, 4R, 5R) -2,3,4,5-tetrakis-allyloxy-tetrahydropyran are initially charged in THF and 900 ml (0.45 mol) of 9-BBN (0, 5 M sol. In THF) are added and the reaction is refluxed for 5 h. After cooling, the mixture is hydrolyzed with water and 40 ml of 50% NaOH are added. 130 ml (1.49 mol) of 30% H ₂ O ₂ are added dropwise, and the mixture is stirred for 19 h. 50 g of potassium carbonate are added and the organic phase is decanted off. The solution is treated with ammonium iron (II) sulfate solution and dried with sodium sulfate. The crude product remaining after removal of the solvent is purified by column chromatography (SiO ₂ , MTBE → methanol). 3 - [(3S, 4R, 5R) -3,4,5-tris- (3-hydroxy-propoxy) -tetrahydropyran-2-yloxy] -propan-1-ol is obtained as a colorless oil.

5.3 Esterification with methacrylic acid

8.0 g (20.9 mmol) of 3 - [(3S, 4R, 5R) -3,4,5-tris- (3-hydroxy-propoxy) -tetrahydropyran-2-yloxy] -propan-1-ol together with 21.3 ml (0.25 mol) of methacrylic acid and 0.2 g (1.6 mmol) of DMAP in 200 ml of THF. A solution of 50.0 g (0.24 mol) of DCC in 100 ml of THF is metered in, and the mixture is stirred for 22 h at room temperature. Oxalic acid dihydrate is added and after 1 h is filtered from the insoluble. The filtrate is completely concentrated and the residue is purified by chromatography. 2-Methacrylic acid-3 - {(3S, 4R, 5R) -2,3,5-tris [3- (2-methyl-acryloyloxy) -propoxy] -tetrahydropyran-4-yloxy} -propyl ester is used as anomeric mixture obtained (α: β = 95: 5).

The ¹ H and ¹³ C NMR spectroscopic data agree with the structure.

MS (EI): m / z (%) = 654 (1, M ⁺ ), 325 (5), 127 (100).

Reference Examples 6-9:

Tg -52 I 7

Tg -53 I 8

Tg -51 I 9

Tg -61 I Analogously to Reference Example 1, the reference example compounds 6-9 are obtained from the corresponding sugars and reacted with bromovaleric acid and methacrylic acid. The spectroscopic data (NMR, MS) correspond respectively to the structures. 6

Tg -52 I 7

Tg -53 I 8th

Tg -51 I 9

Tg -61 I

use Examples

The following acronyms are used to describe the components of the liquid crystalline base (host):

The following monomers are used:

RM220 has the phase sequence K 82.5 N 97 I.

RM257 has the phase sequence K 66 N 127 I.

Tabelle: Zusammensetzung der Basismischung (Host) H1 vor Zugabe der Polymerisationskomponenten: Zusammensetzung Eigenschaften Komponente Anteil T(N, I) 66,6 °C Akronym Gew.-% Δn (20°C, 589 nm) 0.148 PUQU-3-F 5.00 AGUQU-3-F 13.00 AUUQU-2-F 6.00 AUUQU-3-F 10.00 AUUQU-4-F 6.00 AUUQU-5-F 9.00 AUUQU-7-F 6.00 AUUQU-3-T 8.00 AUUQU-3-OT 12.00 PUZU-2-F 6.00 PUZU-3-F 10.00 PUZU-5-F 9.00 Σ 100.00 The following additives are used
(DP: chiral dopant, IN: polymerization initiator)

Table: Composition of the base mixture (host) H1 before addition of the polymerization components: composition properties component proportion of T (N, I) 66.6 ° C acronym Wt .-% Δn (20 ° C, 589 nm) 0148 PUQU-3-F 5:00 AGUQU-3-F 13:00 AUUQU-2-F 6:00 am AUUQU-3-F 10:00 AUUQU-4-F 6:00 am AUUQU-5-F 9:00 AUUQU-7-F 6:00 am AUUQU-3-T 8:00 AUUQU-3-OT 12:00 PUZU-2-F 6:00 am PUZU-3-F 10:00 PUZU-5-F 9:00 Σ 100.00

Description of the polymerization

Before the polymerization of a sample, the phase properties of the medium are determined in a test cell of about 10 micrometers thickness and an area of 2x2.5 cm. The filling is achieved by capillary action at a temperature of 75 ° C. The measurement is carried out under a polarizing microscope with hot stage at a temperature gradient of 1 ° C / min.

The polymerization of the media is carried out by irradiation with a UV lamp (Hönle, Bluepoint 2.1, 365 nm interference filter) with an effective power of about 1.5 mW / cm ² for 180 seconds. The polymerization takes place directly in the electro-optical test cell. The polymerization is initially carried out at a temperature in which the medium is in the blue phase I (BP-I). The polymerization takes place in several substeps, which gradually lead to a complete polymerization. The temperature range of the blue phase usually changes during the polymerization. Between each sub-step, therefore, the temperature is adjusted so that the medium is still present in the blue phase. In practice, this can be done so that after each irradiation process of about 5 s or longer, the sample is observed under the polarizing microscope. If the sample becomes darker, this indicates a transition to the isotropic phase. The temperature for the next sub-step is reduced accordingly. The total irradiation time leading to the maximum stabilization is typically 180 seconds at the indicated irradiation power. Further polymerizations can be carried out according to an optimized irradiation temperature program. Alternatively, the polymerization can also be carried out in a single irradiation step, especially if a broad blue phase is present even before the polymerization.

Electro-optical characterization

After the above-described polymerization and stabilization of the blue phase, the phase width of the blue phase is determined. The electro-optical characterization is then carried out at different temperatures within and possibly outside this range.

The test cells used are equipped on one side with interdigital electrodes on the cell surface. The cell gap, electrode gap and electrode width are typically each 10 microns. This uniform measure is referred to below as the gap width. The area occupied by electrodes is approximately 0.4 cm ² . The test cells do not have an alignment layer. The cell is located between crossed polarizing filters for electro-optical characterization, with the longitudinal direction of the electrodes being at 45 ° to the axes of the polarizing filter. The measurement is carried out with a DMS301 (Autronic-Melchers) at right angles to the cell plane, or by means of a highly sensitive camera on the polarizing microscope. In the de-energized state, the arrangement described results in a substantially dark image (definition 0% transmission).

First, the characteristic operating voltages and then the switching times on the test cell are measured. The operating voltage at the cell electrodes is applied in the form of square-wave voltage with alternating sign (frequency 100 Hz) and variable amplitude as described below.

The transmission in the de-energized state is set as 0%. While the operating voltage is increased, the transmission is measured. Achieving the maximum value of about 100% intensity determines the characteristic magnitude of the operating voltage V ₁₀₀ . Likewise, the characteristic voltage V _{10 is determined} at 10% of the maximum transmission. These values are measured at different temperatures around the blue phase.

At the lower end of the blue phase temperature range, relatively high characteristic operating voltages V _{100 are} observed. At the upper end of the temperature range (near the clearing point), the value of V _{100 increases} sharply. In the range of the minimum operating voltage V ₁₀₀ usually rises only slowly with the temperature. This temperature range, limited by T ₁ and T ₂ , is referred to as a usable, flat temperature range (FB). The width of this "flat area" (FB) is (T ₂ -T ₁ ) and is referred to as the width of the flat area (BFB). The exact values of T ₁ and T ₂ are determined by the intersections of tangents to the flat curve section FB and the adjacent steep curve sections in the V ₁₀₀ temperature diagram.

In the second part of the measurement, the switching times during switching on and off are determined (τ _οn , τ _off ). The switching time τ _on is defined by the time to reach 90% intensity after applying a voltage of the magnitude of V ₁₀₀ at the selected temperature. The switching time τ _off is defined by the time to decrease by 90% starting from maximum intensity at V ₁₀₀ after lowering the voltage to 0 V. The switching time is also determined at different temperatures in the blue phase range.

As a further characterization, at a temperature within FB, the transmission is measured at continuously varying operating voltage between 0 V and V ₁₀₀ . When comparing the curves for increasing and decreasing operating voltage hysteresis can occur. The difference in the transmissions at 0.5 * V ₁₀₀ or the difference in the voltages at 50% transmission are, for example, characteristic hysteresis values and are referred to as ΔT ₅₀ and ΔV ₅₀ , respectively.

Examples of use M1 (for comparison), M2, M3 (for comparison), M4

The following polymerizable media are grouped together: M1 (comparison) M2 M3 (comparison) M4 component Proportion [% by weight] Proportion [% by weight] Proportion [% by weight] Proportion [% by weight] H1 86.3 86.3 85.0 85.0 DP-1 2.5 2.5 3.8 3.8 IN-1 0.2 0.2 0.2 0.2 RM-1 - 3 - 3 RM-257 6.0 - 6.0 - RM-2 5.0 - 5.0 - RM-3 - 8.0 - 8.0

The media are characterized as described before polymerization. Then the RM components are polymerized by single irradiation (180 s) in the blue phase, and the resulting media are characterized again. Measurements Usage Examples M1 M2 M3 M4 Transition point N-BP before the polymerization 38 ° C 33 ° C 31.7 ° C 25.6 ° C Temperature range blue phase -6 ° C - 53 ° C -5 ° C - 52 ° C V ₁₀ (20 ° C) 23.7 v 18.7 v 30.4 V 26.3 v V ₁₀₀ (20 ° C) 58.6V 48.3 v 68.5V 62.0V ΔV ₅₀ (20 ° C) 6.9V 3.4V 8.4 V 3.8V

The inventive RM-1 polymer-stabilized media M2 and M4 show a significant reduction in the operating voltage (V ₁₀ , V ₁₀₀ ) and the hysteresis (.DELTA.V ₅₀ ) compared to the media M1 or M3 (without RM-1). The mixtures M3 and M4 differ from the mixtures M1 and M2 by an increased proportion of chiral dopant, whereby M3 / M4, in contrast to M1 / M2 invisible blue phases form (displacement of the wavelengths in the UV range). Examples M3 and M4 show the reduction of hysteresis and operating voltage by the reference example substance also for invisible blue phases.

Claims (5)

Liquid-crystalline medium which comprises one or more compounds selected from the compounds of the formulas IA-1 to IA-10

in which R ^{1 '} to R ^{5' are} each independently of one another hydrogen, straight-chain or branched alkyl, alkenyl, alkoxy or alkoxymethyl having 1 to 12 C atoms, X ¹ to X ^{5 in} each case independently of one another -O-, -S-, - CO-, -COO-, -OCO-, -O-COO-, -CO-NR ⁰⁰ -, -NR ⁰⁰ -CO-, -NR ⁰⁰ -CO-NR ⁰⁰ -, -OCH ₂ -, -CH ₂ O- , -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF 2, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH = N-, -N = CH-, -N = N-, -CH = CR ⁰ -, -CY ² = CY ³ -, -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or a single bond, R ⁰ and R ^{00 are} each independently H or alkyl of 1 to 12 C atoms, Y ² and Y ^{3 are} each independently H, F, Cl or CN, P ¹ to P ^{5 are} each independently a polymerizable group and Sp ¹ to Sp ⁵ each independently represent a spacer group or a single bond, or which contains a polymer comprising one or more compounds selected from the compounds of the formulas IA-1 to IA-10. A process for the preparation of an electro-optical device with a liquid-crystalline polymer-stabilized medium, which comprises reacting a liquid-crystalline medium comprising one or more compounds of the formulas IA-1 to IA-10 Claim 1 polymerized. Liquid-crystalline medium after Claim 1 , characterized in that it has a blue phase at least in the range of 20 to 25 ° C after stabilization of the blue phase by polymerization. Use of the liquid-crystalline medium after Claim 1 or 3 for electro-optical purposes. Electro-optical liquid crystal display containing a liquid-crystalline medium according to Claim 1 or 3 ,