JPH0892259A - Silacyclohexane compound, method for producing the same, and liquid crystal composition containing the same - Google Patents

Abstract

(57) [Summary] [Object] To provide a liquid crystal compound having a silacyclohexane ring. [Structure] A silacyclohexane compound represented by the following general formula (I). However, R is a linear alkyl group having 1 to 10 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, and 3 to 3 carbon atoms.
It represents a branched alkyl group having 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. Is a trans-1-sila-1,4-cyclohexylene group or trans-4-sila-1,4-cyclohexylene group in which the silicon at the 1- or 4-position has a substituent of H, F, Cl or CH _3. Represent L ₁ and L ₂ each independently represent H or F. L ₃ and L ₄ are each independently H,
Represents F or Cl. X is H, CN, F, Cl, CF ₃ ,
CF ₂ Cl, CHFCl, OCF ₃ , OCF ₂ Cl, OC
HFCl, OCHF ₂ , a linear alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is represented. i represents 0, 1 or 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel silacyclohexane compound, a method for producing the same, a liquid crystal composition containing the same, and a liquid crystal display device containing the liquid crystal composition.

[0002]

2. Description of the Related Art A liquid crystal display device utilizes the optical anisotropy and dielectric anisotropy of a liquid crystal material, and depending on its display mode, it is a TN type (twisted nematic type) or an STN type (super twisted nematic type). ), SBE type (super birefringence type),
There are various types such as a DS type (dynamic scattering type), a guest-host type, a DAP type (aligned phase deformation type), and an OMI type (optical mode interference type). The most common display device is based on the Schut-Helfrich effect and has a twisted nematic structure.

The properties required for the liquid crystal substances used for these liquid crystal displays are slightly different depending on the display system, but they are stable against a wide range of liquid crystal temperature, moisture, air, light, heat, electric field and the like. Things are commonly requested in any display method. Furthermore, it is desired that the liquid crystal material has a low viscosity and provides a short addressing time, a low threshold voltage and a high contrast in the cell.

At present, there is no substance that satisfies all of these requirements with a single compound, and actually, a liquid crystal mixture obtained by mixing several to several dozen liquid crystal compounds / latent liquid crystal compounds is used. . Therefore, it is also important that the components be easily miscible with each other.

Among these constituents, the following compounds are known as liquid crystal substances having a high T _NI (nematic-isotropic transition temperature) and a high Δn (refractive index anisotropy) at the same time.

[0006]

[Chemical 13] (Z ₁ , Z ₂ and Z ₃ are each independently H or F, X is F, CN or Cl.) (Table 3-50)
(See Japanese Patent No. 3771)

[0007]

In recent years, as the applications of liquid crystal displays have expanded, the characteristics required of liquid crystal materials have become more sophisticated, and the driving method,
The operation modes are also diversifying.

Especially for in-vehicle use, a liquid crystal material having a nematic phase expanded to a high temperature is required due to its use environment. In order to extend the nematic phase to the high temperature part, a liquid crystal compound having a high T _N1 (nematic-isotropic transition temperature) may be added to the constituent components.

On the other hand, an STN (Super Twisted Nematic) mode has been known as a conventionally known operation mode. Recently, an active addressing drive system for improving the low response speed, which is a drawback thereof, has been developed and put into practical use. is there. As the liquid crystal material used for this purpose, a liquid crystal material having a high Δn (refractive index anisotropy) corresponding to a narrow cell gap is required.

On the other hand, a PDLC (polymer dispersed liquid crystal) method or a PNLC (polymer network liquid crystal) method has been proposed as a new display method, and development is proceeding toward practical use. Since all of these display modes are scattering modes, a liquid crystal material having a large Δn is required to increase the contrast.

[0012] From such a viewpoint, the present invention has a high T _NI simultaneously large [Delta] n, and the molecular structure that was not previously known a completely novel liquid crystal compound having a silacyclohexane ring containing a silicon atom The purpose is to provide.

[0013]

That is, the present invention is a silacyclohexane compound represented by the following general formula (I).

Embedded image However, R is a linear alkyl group having 1 to 10 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, and 3 to 3 carbon atoms.
It represents a branched alkyl group having 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.

[Chemical 15] Is a trans-1-sila-1,4-cyclohexylene group or trans-4-sila-1,4-cyclohexylene group in which silicon at the 1- or 4-position has a substituent of H, F, Cl or CH _3. Represent L ₁ and L ₂ are independently of each other H
Or F. L ₃ and L ₄ each independently represent H, F or Cl. X is H, CN, F, Cl, CF
₃ , CF ₂ Cl, CHFCl, OCF ₃ , OCF ₂ Cl, O
CHFCl, OCHF ₂ , a linear alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is represented. i represents 0, 1 or 2.

The present invention also relates to an organometallic reagent.

Embedded image RM (M is MgP (P represents halogen), ZnP or L
represents i. )When

[Chemical 17] (Q is a halogen or an alkoxy group (preferably having a carbon number of 1 to
4 alkoxy group), a methanesulfonyloxy group, a benzenesulfonyloxy group, a p-toluenesulfonyloxy group or a trifluoromethanesulfonyloxy group. ) With a carbon-carbon bond forming reaction or a carbon-silicon bond forming reaction with the above), the method for producing a silacyclohexane compound represented by the above general formula (I).

The present invention also relates to an organometallic reagent.

[Chemical 18] (W is H, F, Cl or CH ₃ , preferably H or CH ₃
Represents )When

[Chemical 19] The method for producing a silacyclohexane compound represented by the general formula (I) is characterized in that it is carried out by a carbon-carbon bond forming reaction with.

The present invention also relates to an organometallic reagent.

Embedded image When

[Chemical 21] (M and n are 0, 1 or 2 and represent an integer satisfying m + n = 2) by a carbon-carbon bond forming reaction of the silacyclohexane compound represented by the above general formula (I). It is a manufacturing method.

The present invention also relates to an organometallic reagent.

[Chemical formula 22] When

[Chemical formula 23] The method for producing a silacyclohexane compound represented by the general formula (I) is characterized in that it is carried out by a carbon-carbon bond forming reaction with.

The present invention also relates to an organometallic reagent.

[Chemical formula 24] (M ′ is M, B (OR ′) ₂ (R ′ is an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms) or a hydrogen atom) or TiP _k (OR ″) _3-k (P is Halogen, R "
Is an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms)
k represents an integer of 0 to 3. ) Represents. )When

[Chemical 25] The method for producing a silacyclohexane compound represented by the general formula (I) is characterized in that it is carried out by a carbon-carbon bond forming reaction with.

Further, the present invention is a liquid crystal composition containing the silacyclohexane compound represented by the general formula (I) and a liquid crystal display device containing the liquid crystal composition. .

Next, the present invention will be described in more detail by showing specific examples of the silacyclohexane compound represented by the general formula (I).

Examples of the novel ring structure of the present invention include a reduced structure containing the following trans-1- or trans-4-silacyclohexane ring.

[0022]

[Chemical formula 26]

[0023]

[Chemical 27]

R represents any of the following. (A) A linear alkyl group having 1 to 10 carbon atoms, that is, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-
Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group or n-decyl group. (B) a mono- or difluoroalkyl group having 1 to 10 carbon atoms,
That is, fluoromethyl group, 1-fluoroethyl group, 1-fluoropropyl group, 1-fluorobutyl group, 1-fluoropentyl group, 1-fluorohexyl group, 1-fluoroheptyl group,
1-fluorooctyl group, 1-fluorononyl group, 1-fluorodecyl group, 2-fluoroethyl group, 2-fluoropropyl group, 2-fluorobutyl group, 2-fluoropentyl group, 2-
Fluorohexyl group, 2-fluoroheptyl group, 2-fluorooctyl group, 2-fluorononyl group, 2-fluorodecyl group, 3-fluoropropyl group, 3-fluorobutyl group, 3-
Fluoropentyl group, 3-fluorohexyl group, 3-fluoroheptyl group, 3-fluorooctyl group, 3-fluorononyl group, 3-fluorodecyl group, 4-fluorobutyl group, 4-fluoropentyl group, 4-fluorohexyl group, 4 -Fluoroheptyl group, 4-fluorooctyl group, 4-fluorononyl group, 4-fluorodecyl group, 5-fluoropentyl group, 5-
Fluorohexyl group, 5-fluoroheptyl group, 5-fluorooctyl group, 5-fluorononyl group, 5-fluorodecyl group, 6-fluorohexyl group, 6-fluoroheptyl group, 6
-Fluorooctyl group, 6-fluororonyl group, 6-fluorodecyl group, 7-fluoroheptyl group, 7-fluorooctyl group, 7-fluorononyl group, 7-fluorodecyl group, 8-fluorooctyl group, 8-fluororonyl group, 8- Fluorodecyl group, 9-fluorononyl group, 9-fluorodecyl group, 10
-Fluorodecyl group, difluoromethyl group, 1,1-difluoroethyl group, 1,1-difluoropropyl group, 1,1-difluorobutyl group, 1,1-difluoropentyl group, 1,1
-Difluorohexyl group, 1,1-difluoroheptyl group,
1,1-difluorooctyl group, 1,1-difluorononyl group, 1,1-difluorodecyl group, 2,2-difluoroethyl group, 2,2-difluoropropyl group, 2,2-difluorobutyl group, 2,2- Difluoropentyl group, 2,2-difluorohexyl group, 2,2-difluoroheptyl group, 2,2
-Difluorooctyl group, 2,2-difluorononyl group,
2,2-difluorodecyl group, 3,3-difluoropropyl group, 3,3-difluorobutyl group, 3,3-difluoropentyl group, 3,3-difluorohexyl group, 3,3-difluoroheptyl group, 3,3-difluorooctyl group, 3,3-
Difluorononyl group, 3,3-difluorodecyl group, 4,4
-Difluorobutyl group, 4,4-difluoropentyl group,
4,4-difluorohexyl group, 4,4-difluoroheptyl group, 4,4-difluorooctyl group, 4,4-difluorononyl group, 4,4-difluorodecyl group, 5,5-difluoropentyl group, 5,5-difluorohexyl group, 5,5-
Difluoroheptyl group, 5,5-difluorooctyl group,
5,5-difluorononyl group, 5,5-difluorodecyl group, 6,6-difluorohexyl group, 6,6-difluoroheptyl group, 6,6-difluorooctyl group, 6,6-difluororonyl group, 6, 6-difluorodecyl group, 7,7-difluoroheptyl group, 7,7-difluorooctyl group, 7,
7-difluorononyl group, 7,7-difluorodecyl group,
8,8-difluorooctyl group, 8,8-difluororonyl group, 8,8-difluorodecyl group, 9,9-difluororonyl group, 9,9-difluorodecyl group or 10,10-difluorodecyl group. (C) a branched chain alkyl group having 3 to 8 carbon atoms, that is, isopropyl group, sec-butyl group, isobutyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3
-Methylpentyl group, 1-ethylpentyl group, 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 1-methylheptyl group, 2-methylheptyl group Or a 3-methylheptyl group. (D) an alkoxyalkyl group having 2 to 7 carbon atoms, that is, a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, a pentoxymethyl group, a hexyloxymethyl group, a methoxyethyl group, an ethoxyethyl group,
Propoxyethyl group, butoxyethyl group, pentoxyethyl group, methoxypropyl group, ethoxypropyl group, propoxypropyl group, butoxypropyl group, methoxybutyl group, ethoxybutyl group, propoxybutyl group, methoxypentyl group, ethoxypentyl group or methoxy Hexyl group. (E) an alkenyl group having 2 to 8 carbon atoms, that is, a vinyl group,
1-propenyl group, allyl group, 1-butenyl group, 3-butenyl group, isoprenyl group, 1-pentenyl group, 3-pentenyl group, 4-pentenyl group, dimethylallyl group, 1
-Hexenyl group, 3-hexenyl group, 5-hexenyl group, 1-heptenyl group, 3-heptenyl group, 6-heptenyl group or 7-octenyl group.

W represents an H, F, Cl or CH ₃ group.

L ₁ and L ₂ each independently represent H or F, and L ₃ and L ₄ each independently represent H or F.
Represents F or Cl.

X is H, CN, F, Cl, CF ₃ , CF ₂ C
1, CHFCl, OCF ₃ , OCF ₂ Cl, OCHFC
1 or OCHF ₂ or any of the following groups. (F) a linear alkyl group having 1 to 10 carbon atoms, that is, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-
Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group or n-decyl group. (G) a straight-chain alkoxy group having 1 to 10 carbon atoms, that is, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentoxy group, n-hexyloxy group, n-heptyloxy group, n- Octyloxy group, n-nonyloxy group or n-decyloxy group.

Next, a partial skeleton structure of the silacyclohexane compound represented by the general formula (I)

[Chemical 28] Specific examples of the following include the following.

[0029]

[Chemical 29]

[0030]

[Chemical 30]

[0031]

[Chemical 31]

[0032]

[Chemical 32]

[0033]

[Chemical 33]

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

[0037]

Embedded image

[0038]

[Chemical 38]

Next, a partial skeleton structure of the silacyclohexane compound represented by the general formula (I)

[Chemical Formula 39] Specific examples of the following include the following.

[0040]

[Chemical 40]

[0041]

Embedded image

[0042]

[Chemical 42]

[0043]

[Chemical 43]

[0044]

[Chemical 44]

[0045]

[Chemical formula 45]

[0046]

[Chemical formula 46]

[0047]

[Chemical 47]

[0048]

[Chemical 48]

[0049]

[Chemical 49]

[0050]

[Chemical 50]

[0051]

[Chemical 51]

[0052]

[Chemical 52]

[0053]

Embedded image

[0054]

[Chemical 54]

[0055]

[Chemical 55]

[0056]

[Chemical 56]

[0057]

[Chemical 57]

[0058]

[Chemical 58]

[0059]

Embedded image

[0060]

[Chemical 60]

[0061]

[Chemical formula 61]

[0062]

[Chemical formula 62]

[0063]

[Chemical formula 63]

[0064]

[Chemical 64]

[0065]

[Chemical 65]

[0066]

[Chemical formula 66]

[0067]

Embedded image

[0068]

[Chemical 68]

[0069]

[Chemical 69]

[0070]

Embedded image

[0071]

[Chemical 71]

[0072]

[Chemical 72]

[0073]

Embedded image

Among these specific examples, the following are particularly preferable for practical use.

Regarding the ring structure,

[Chemical 74] What is represented by is preferable.

Regarding R, one of the following is preferable. (K) a linear alkyl group having 2 to 7 carbon atoms, that is, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group,
n-hexyl group or n-heptyl group. (I) Among mono- or difluoroalkyl groups having 1 to 10 carbon atoms, 2-fluoroethyl group, 2-fluoropropyl group,
2-fluorobutyl group, 2-fluoropentyl group, 2-fluorohexyl group, 2-fluoroheptyl group, 4-fluorobutyl group, 4-fluoropentyl group, 4-fluorohexyl group,
4-fluoroheptyl group, 5-fluoropentyl group, 5-fluorohexyl group, 5-fluoroheptyl group, 6-fluorohexyl group, 6-fluoroheptyl group, 7-fluoroheptyl group, 2,2-difluoroethyl group, 2 , 2-difluoropropyl group, 2,2-difluorobutyl group, 2,2-difluoropentyl group, 2,2-difluorohexyl group, 2,2-difluoroheptyl group, 4,4-difluorobutyl group, 4 , 4
-Difluoropentyl group, 4,4-difluorohexyl group,
4,4-difluoroheptyl group, 5,5-difluoropentyl group, 5,5-difluorohexyl group, 5,5-difluoroheptyl group, 6,6-difluorohexyl group, 6,6-di Fluoroheptyl group or 7,7-difluoroheptyl group. (J) Of branched-chain alkyl groups, isopropyl group, 1
-Methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methylpentyl group, 2-methylpentyl group or 2-ethylhexyl group. (K) An alkoxyalkyl group having 2 to 6 carbon atoms, that is, a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxypentyl group, an ethoxymethyl group, an ethoxyethyl group, a propoxymethyl group or a pentoxymethyl group. (L) Among alkenyl groups, vinyl group, 1-propenyl group, 3-butenyl group, 1-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5-hexenyl group, 6-heptenyl group Or a 7-octenyl group.

For W, H, F or CH ₃ groups are preferred.

Partial skeleton structure

[Chemical 75] As for, the following are preferable.

[0079]

[Chemical 76]

[0080]

Embedded image

[0081]

Embedded image

[0082]

[Chemical 79]

Partial skeleton structure

Embedded image As for, the following are preferable.

[0084]

[Chemical 81]

[0085]

[Chemical formula 82]

[0086]

[Chemical 83]

[0087]

[Chemical 84]

[0088]

[Chemical 85]

[0089]

[Chemical 86]

[0090]

[Chemical 87]

[0091]

Embedded image

[0092]

[Chemical 89]

[0093]

[Chemical 90]

[0094]

Embedded image

[0095]

Embedded image

[0096]

Embedded image

[0097]

[Chemical 94]

[0098]

[Chemical 95]

[0099]

[Chemical 96]

[0100]

[Chemical 97]

[0101]

[Chemical 98]

Next, the method for producing the silacyclohexane compound represented by the general formula (I) of the present invention will be described. Although the reaction substrates differ slightly depending on the ring structure, they are commonly produced by the coupling reaction of the organometallic reagents shown below.

First, an organometallic reagent

Embedded image RM (M is MgP (P represents halogen), ZnP or L
represents i. )When

[Chemical 100] (Q is a halogen or an alkoxy group (preferably having a carbon number of 1 to
4 alkoxy group), a methanesulfonyloxy group, a benzenesulfonyloxy group, a p-toluenesulfonyloxy group or a trifluoromethanesulfonyloxy group. ) With

[Chemical 101] But

[Chemical 102] (W represents an H, F, Cl or CH ₃ group), Q includes a halogen or an alkoxy group,
Particularly, a Cl, Br, OCH ₃ or OCH ₂ CH ₃ group is preferable because this carbon-silicon bond forming reaction easily proceeds and the target product is obtained in a high yield.

Also,

Embedded image But

[Chemical 104] , The carbon-carbon bond forming reaction is carried out in the presence of a catalytic amount of a copper salt. As the copper compound, monovalent copper salts such as copper (I) chloride, copper (I) bromide, copper (I) iodide, and copper (I) cyanide, copper (II) chloride, copper bromide (I)
I), copper (II) iodide, copper (II) acetate, and other divalent copper salts; and copper complexes such as dilithium tetrachlorocuprate and the like. Examples of Q include a halogen atom and a sulfonyloxy group, and Br or I is particularly preferable because it gives the desired product in a high yield.

Next, an organometallic reagent

[Chemical 105] When

[Chemical formula 106] In reaction with

[Chemical formula 107] But

[Chemical 108] , The carbon-carbon bond forming reaction is carried out in the presence of a transition metal catalyst.

As the transition metal catalyst, a palladium or nickel compound is particularly preferable. Examples of the palladium catalyst include zero-valent palladium compounds such as tetrakis (triphenylphosphine) palladium (0) and di [1,2-bis (diphenylphosphino) ethane] palladium (0), or palladium acetate and palladium chloride. ,
A compound composed of a divalent palladium compound such as [1,1′-bis (diphenylphosphino) ferrocene] palladium (II) chloride and a ligand, or a combination of these with a reducing agent can be used.

As the nickel catalyst, for example, [1,3-
Bis (diphenylphosphino) propane] nickel (I
Divalent nickel compounds such as I) chloride, [1,2-bis (diphenylphosphino) ethane] nickel (II) chloride, bis (triphenylphosphine) nickel (II) chloride, and tetrakis (triphenylphosphine) nickel Examples thereof include zero-valent nickel compounds such as (0).

Examples of Q include halogen, a methanesulfonyloxy group, a p-toluenesulfonyloxy group and a trifluoromethanesulfonyloxy group, and particularly C
I, Br, I or a trifluoromethanesulfonyloxy group is preferable because it gives the target compound in a high yield.

When the leaving group Q is a trifluoromethanesulfonyloxy group, the addition of a lithium salt such as lithium chloride or lithium bromide improves the yield.

Further, an organometallic reagent

[Chemical 109] When

[Chemical 110] (M and n are 0, 1 or 2 and represent an integer satisfying m + n = 2),

[Chemical 111] Where m = 0,1 the carbon-carbon bond forming reaction is carried out in the presence of a catalytic amount of a copper salt. As a copper compound,
Monovalent copper salts such as copper (I) chloride, copper (I) bromide, copper (I) iodide, and copper (I) cyanide, copper (II) chloride, copper (II) bromide, copper iodide (II), divalent copper salts such as copper (II) acetate, and copper complexes such as dilithium tetrachlorocuprate. Examples of Q include a halogen and a sulfonyloxy group, and Br or I is particularly preferable because it gives the desired product in a high yield.

In addition,

[Chemical 112] When m = 2, the carbon-carbon bond forming reaction is carried out in the presence of a transition metal catalyst.

As the transition metal catalyst, a palladium or nickel compound is particularly preferable. Examples of the palladium catalyst include zero-valent palladium compounds such as tetrakis (triphenylphosphine) palladium (0) and di [1,2-bis (diphenylphosphino) ethane] palladium (0), or palladium acetate and palladium chloride. ,
A compound composed of a divalent palladium compound such as [1,1′-bis (diphenylphosphino) ferrocene] palladium (II) chloride and a ligand, or a combination of these with a reducing agent can be used.

As the nickel catalyst, for example, [1,3-
Bis (diphenylphosphino) propane] nickel (I
Divalent nickel compounds such as I) chloride, [1,2-bis (diphenylphosphino) ethane] nickel (II) chloride, bis (triphenylphosphine) nickel (II) chloride, and tetrakis (triphenylphosphine) nickel Examples thereof include zero-valent nickel compounds such as (0).

Examples of Q include halogen, a methanesulfonyloxy group, a p-toluenesulfonyloxy group and a trifluoromethanesulfonyloxy group, and particularly C
I, Br, I or a trifluoromethanesulfonyloxy group is preferable because it gives the target compound in a high yield.

When the leaving group Q is a trifluoromethanesulfonyloxy group, addition of a lithium salt such as lithium chloride or lithium bromide brings about an improvement in yield.

Further, an organometallic reagent

[Chemical 113] When

[Chemical 114] In reaction with

[Chemical 115] Where n = 0,1 the carbon-carbon bond forming reaction is carried out in the presence of a catalytic amount of a copper salt. As a copper compound,
Monovalent copper salts such as copper (I) chloride, copper (I) bromide, copper (I) iodide, and copper (I) cyanide, copper (II) chloride, copper (II) bromide, copper iodide (II), divalent copper salts such as copper (II) acetate, and copper complexes such as dilithium tetrachlorocuprate. Examples of Q include a halogen and a sulfonyloxy group, and Br or I is particularly preferable because it gives the desired product in a high yield.

In addition,

[Chemical formula 116] Is n = 2, the carbon-carbon bond forming reaction is carried out in the presence of a transition metal catalyst.

As the transition metal catalyst, a palladium or nickel compound is particularly preferable. Examples of the palladium catalyst include zero-valent palladium compounds such as tetrakis (triphenylphosphine) palladium (0) and di [1,2-bis (diphenylphosphino) ethane] palladium (0), or palladium acetate and palladium chloride. ,
A compound composed of a divalent palladium compound such as [1,1′-bis (diphenylphosphino) ferrocene] palladium (II) chloride and a ligand, or a combination of these with a reducing agent can be used.

As the nickel catalyst, for example, [1,3-
Bis (diphenylphosphino) propane] nickel (I
Divalent nickel compounds such as I) chloride, [1,2-bis (diphenylphosphino) ethane] nickel (II) chloride, bis (triphenylphosphine) nickel (II) chloride, and tetrakis (triphenylphosphine) nickel Examples thereof include zero-valent nickel compounds such as (0).

Examples of Q include halogen, a methanesulfonyloxy group, a p-toluenesulfonyloxy group and a trifluoromethanesulfonyloxy group, and particularly C
I, Br, I or a trifluoromethanesulfonyloxy group is preferable because it gives the target compound in a high yield.

When the leaving group Q is a trifluoromethanesulfonyloxy group, addition of a lithium salt such as lithium chloride or lithium bromide brings about an improvement in yield.

Also, an organometallic reagent

[Chemical 117] (M ′ is M, B (OR ′) ₂ (R ′ is an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms) or a hydrogen atom) or TiP _k (OR ″) _3-k (P is Halogen, R "
Is an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms)
k represents an integer of 0 to 3. ) Represents. )When

[Chemical 118] The carbon-carbon bond forming reaction with and is carried out in the presence of a transition metal catalyst.

As the transition metal catalyst, a palladium or nickel compound is particularly preferable. Examples of the palladium catalyst include zero-valent palladium compounds such as tetrakis (triphenylphosphine) palladium (0) and di [1,2-bis (diphenylphosphino) ethane] palladium (0), or palladium acetate and palladium chloride. ,
A compound composed of a divalent palladium compound such as [1,1′-bis (diphenylphosphino) ferrocene] palladium (II) chloride and a ligand, or a combination of these with a reducing agent can be used.

As the nickel catalyst, for example, [1,3-
Bis (diphenylphosphino) propane] nickel (I
Divalent nickel compounds such as I) chloride, [1,2-bis (diphenylphosphino) ethane] nickel (II) chloride, bis (triphenylphosphine) nickel (II) chloride, and tetrakis (triphenylphosphine) nickel Examples thereof include zero-valent nickel compounds such as (0).

Examples of Q include halogen, a methanesulfonyloxy group, a p-toluenesulfonyloxy group and a trifluoromethanesulfonyloxy group, and particularly C
I, Br, I or a trifluoromethanesulfonyloxy group is preferable because it gives the target compound in a high yield.

When the leaving group Q is a trifluoromethanesulfonyloxy group, addition of a lithium salt such as lithium chloride or lithium bromide brings about an improvement in yield.

Further, when M'is B (OR ') ₂ , the reaction is preferably carried out in the presence of a base. Examples of the base include sodium carbonate, sodium hydrogen carbonate,
Inorganic bases such as potassium carbonate, sodium hydroxide and potassium hydroxide, and organic bases such as triethylamine, dimethylaniline and tributylamine can be used.

From the product obtained by the above reaction, the desired silacyclohexane compound can be obtained by a purification operation after a usual post-treatment operation. When the configuration of the silacyclohexane ring is a mixture of trans isomer and cis isomer, the trans isomer can be separated by a conventional purification means such as chromatography or recrystallization.

Next, known compounds used for forming a liquid crystal phase by mixing with the silacyclohexane compound of the present invention are:

[Chemical formula 119]

[Chemical 120] Chosen from.

In addition, in [Chemical formula 119] and [Chemical formula 120], (M) and (N) represent any of the following. One or more F or C, which is unsubstituted or has a substituent
1, Br, CN, trans-1,4 having an alkyl group
-Cyclohexylene group. Trans- in which one or two non-adjacent CH ₂ groups in the cyclohexane ring are replaced by O or S
1,4-cyclohexylene group. 1,4-cyclohexenylene group. One or two F, Cl, C which is unsubstituted or substituted
A 1,4-phenylene group having an H ₃ or CN group. A 1,4-phenylene group in which one or two CH groups in the ring are replaced by N atoms.

Z ¹ and Z ² are --CH ₂ CH _2- , --CH =
CH -, - C≡C -, - CO 2 -, - OCO -, - CH 2
O -, - represents a single bond or - OCH _2.

L (el) and m are 0, 1 or 2 (provided that
1 + m = 1, 2, 3), and n is 0, 1 or 2.

R is a linear alkyl group having 1 to 10 carbon atoms,
It represents a branched chain alkyl group having 3 to 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms.

X is H, CN, F, Cl, CF ₃ , CF ₂ C
1, CHFCl, OCF ₃ , OCF ₂ Cl, OCHFC
1, OCHF ₂ , a linear alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

Y and Z each independently represent H or F.

In the above, when l (ell) and n are both 2, (M) may contain heterocyclic rings, and when m is 2, (N) may contain heterocyclic rings.

The proportion of the silacyclohexane compound of the present invention in the liquid crystal phase may be 1 to 50 or more.
%, Preferably 5 to 30%. Further, the liquid crystal phase may contain a polychromatic dye for forming a colored guest-host system or an additive for changing the dielectric anisotropy, the viscosity and the orientation of the nematic phase.

The liquid crystal phase thus formed is enclosed between transparent substrates having electrodes of a desired shape and used as a liquid crystal display element. This element may have various undercoats, alignment control overcoats, polarizing plates, filters, reflective layers, and the like, if necessary. Further, various types such as a multi-layer cell, a combination with another display element, a semiconductor substrate, or a light source can be used.

As a method of driving the liquid crystal display element,
Dynamic scattering (DSM) system, twisted nematic (TN) system, guest host (GH) system, super twisted nematic (STN) system,
Polymer dispersion (PDLC) system, polymer network (PNLC) system, electric field control birefringence (ECB) system, etc.
A method known in the liquid crystal display device industry can be adopted.

[0140]

EXAMPLES The present invention will be described in more detail with reference to specific examples.

[Example 1] trans-4- (2- (4- (4-n-propyl-4-
Silacyclohexyl) phenyl) ethyl) -3 ', 4'
-Production of difluorobiphenyl 2.5 g (20 mmol) of n-propyl bromide was added to a mixture of 0.5 g (21 mmol) of magnesium and 50 ml of tetrahydrofuran (hereinafter abbreviated as "THF").
Was added dropwise to obtain a Grignard reagent. Subsequently, this solution was added to a solution of 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -3 ′, 4′-difluorobiphenyl (8.5 g, 20 mmol) in THF (50 ml).
To give a crude product. This is a mixture of trans and cis isomers with respect to the silacyclohexane ring,
After the usual post-treatment, these were separated by chromatography to give 7.5 g of the target product in trans form (yield 86%).
Got C-N transition temperature: 63 ° C, NI transition temperature: 155 ° C IR (KBr disc) νmax: 2914, 28
62, 2102, 1605, 1506, 984, 88
7,881,816,775 cm ^-1

The following compounds were obtained in the same manner as in Example 1.

Example 2 Trans-4-using n-propyl bromide and 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -2,4'-difluorobiphenyl. (2- (4- (4-n-propyl-4-silacyclohexyl) phenyl) ethyl)
-2,4'-Difluorobiphenyl was obtained.

Example 3 Using n-propyl bromide and 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -2,3 ', 4'-trifluorobiphenyl Trans-4- (2- (4- (4
-N-propyl-4-silacyclohexyl) phenyl)
Ethyl) -2,3 ', 4'-trifluorobiphenyl was obtained.

Example 4 Using n-propyl bromide and 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'-n-propylbiphenyl Trans-4- (2- (4-
(4-n-Propyl-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4′-n-propylbiphenyl was obtained.

Example 5 Trans-using n-pentyl bromide and 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'-chlorobiphenyl 4- (2- (4- (4-
n-Pentyl-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4′-chlorobiphenyl was obtained.

Example 6 Trans-using n-pentyl bromide and 4- (2- (4- (4-chloro-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'-cyanobiphenyl 4- (2- (4- (4-
n-Pentyl-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4′-n-propoxybiphenyl was obtained.

Example 7 4- (2-Bromoethyl)-
2,3 ', 4'-trifluorobiphenyl and 4- (4
Trans-4- (2) with-(3-methoxypropyl) -4-silacyclohexyl) -1-bromobenzene
-(4- (4-n-Pentyl-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'-cyanobiphenyl was obtained.

Example 8 Trans-4- (2- (4- (4-n-pentyl-4-
Silacyclohexyl) phenyl) ethyl) -3,4'-
Preparation of difluorobiphenyl Magnesium 0.5 g (21 mmol) and THF 50
To a mixture of ml, 4- (2-bromoethyl) -3,4 '
-5.9 g (20 mmol) of difluorobiphenyl was added dropwise to obtain a Grignard reagent. Subsequently, this solution is added to 4-
(4-n-pentyl-4-silacyclohexyl) -1-
6.5 g (20 mmol) of bromobenzene and a catalytic amount of tetrakis (triphenylphosphine) palladium (0)
Was added dropwise to a THF solution (50 ml) to obtain a crude product. This is a mixture of trans-form and cis-form with respect to the silacyclohexane ring, and after usual post-treatment, these were separated by chromatography to obtain 7.6 g of the target product of trans-form (yield 82%). It was

The following compounds were obtained as in Example 8.

[Example 9] 4- (2-bromoethyl)-
2,3 ', 4'-trifluorobiphenyl and 4- (4
Trans-4- (2) with-(3-methoxypropyl) -4-silacyclohexyl) -1-bromobenzene
-(4- (4- (3-Methoxypropyl) -4-silacyclohexyl) phenyl) ethyl) -2,3 ', 4'-
Trifluorobiphenyl was obtained.

Example 10 4- (2-Bromoethyl)
-2-Fluoro-4'-n-propylbiphenyl and 4
Trans-4- (2) using-(4- (3-pentenyl) -4-silacyclohexyl) -1-bromobenzene
-(4- (4- (3-Pentenyl) -4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'-n
-Propyl biphenyl was obtained.

Example 11 trans-4- (2- (4- (4-n-pentyl-4-
Silacyclohexyl) phenyl) ethyl) -2 ', 3'
Preparation of -difluoro-4'-n-propoxybiphenyl 0.5 g (21 mmol) magnesium and THF50
In a mixture of ml, 6.5 g of 4- (4-n-pentyl-4-silacyclohexyl) -1-bromobenzene (20 m
(mol) was added dropwise to obtain a Grignard reagent. Subsequently, this solution was treated with 7.1 g of 4- (2-bromoethyl) -2 ′, 3′-difluoro-4′-n-propoxybiphenyl.
(20 mmol), a catalytic amount of copper (I) iodide and triethylphosphite were added dropwise to 50 ml of a THF solution to obtain a crude product. This is a mixture of trans-form and cis-form with respect to the silacyclohexane ring, and after the usual post-treatment, these were separated by chromatography to obtain 8.3 g of the target product of trans-form (yield 80%). It was

The following compounds were obtained as in Example 11.

[Example 12] 4- (4-isobutyl-4)
-Silacyclohexyl) -1-bromobenzene and 4-
Trans-4- (2- (4- (4-isobutyl-4-silacyclohexyl) phenyl) ethyl) -2-fluoro-4'- using (2-bromoethyl) -2-fluoro-4'-cyanobiphenyl. Cyanobiphenyl was obtained.

[Example 13] 4- (4-n-pentyl-
4-methyl-4-silacyclohexyl) -1-bromobenzene and 4- (2-bromoethyl) -4'-cyanobiphenyl were used to provide trans-4- (2- (4- (4-n
-Pentyl-4-methyl-4-silacyclohexyl) phenyl) ethyl) -4'-cyanobiphenyl was obtained.

Example 14 trans-4- (2- (4- (4-n-pentyl-4-
Silacyclohexyl) phenyl) ethyl) -3 ', 4'
-Preparation of difluorobiphenyl 0.5 g (21 mmol) magnesium and THF 50
To a mixture of ml, 3.9 g (20 mmol) of 3,4-difluorobromobenzene was added dropwise to obtain a Grignard reagent. This is 2.8 g (20 mmol) of zinc chloride in TH
20 ml of F solution was added dropwise to obtain an organozinc reagent. Subsequently, this solution was added to 4- (2- (4- (4-n-pentyl-4-silacyclohexyl) phenyl) ethyl) -1-.
Bromobenzene (8.6 g, 20 mmol) and a catalytic amount of 1,3-bis (diphenylphosphino) propane nickel (II) chloride were added dropwise to a THF solution (50 ml) to obtain a crude product. This is a mixture of a trans form and a cis form with respect to the silacyclohexane ring, and after the usual post-treatment, these were separated by chromatography to obtain 8.3 g of the target product of the trans form (yield 90%). It was

The following compounds were obtained as in Example 14.

Example 15 4-Fluorobromobenzene and 4- (2- (4- (4-n-propyl-1-silacyclohexyl) phenyl) ethyl) -2-fluoro-
Trans-4- (2- (4
-(4-n-Propyl-1-silacyclohexyl) phenyl) ethyl) -2,4'-difluorobiphenyl was obtained.

Example 16 4-Fluorobromobenzene and 4- (2- (4- (4-n-pentyl-1-fluoro-1-silacyclohexyl) phenyl) ethyl)-
Trans-4- (2- (4
-(4-n-Pentyl-1-fluoro-1-silacyclohexyl) phenyl) ethyl) -4'-fluorobiphenyl was obtained.

Example 17 Trans-4- (2- (trans-4- (3,4-difluorophenyl) cyclohexyl) ethyl) -1-n-ethyl-1-cyclohexane 45%, trans-4- ( 2- (trans-4-
(3,4-Difluorophenyl) cyclohexyl) ethyl) -1-n-propyl-1-cyclohexane 15% and trans-4- (2- (trans-4- (3,4-difluorophenyl) cyclohexyl) ethyl)- 1-n
Mixture A consisting of 40% pentyl-1-cyclohexane exhibits the following properties: T _NI (nematic-isotropic transition temperature) = 96
° C. T _CN (crystal - nematic transition temperature) = - 10 ℃ Δn (refractive index anisotropy, 25 ℃) = 0.0718

85% of this mixture A and trans-4- (2- (4- (4-n-propyl-4-) obtained in Example 1)
Silacyclohexyl) phenyl) ethyl) -3 ', 4'
The mixture consisting of 15% of difluorobiphenyl resulted in an increase in Δn with an increase in T _{NI and a} decrease in T _CN , as shown below. T _NI = 103 ° C T _CN = -16 ° C Δn = 0.0864

[0163]

As described above, the present invention has a high T _NI.
A completely novel liquid crystal compound having a large Δn (refractive index anisotropy) at the same time as (nematic-isotropic transition temperature) and a silacyclohexane ring containing a silicon atom in a molecular structure that has not been heretofore known. Could be provided. The high T _NI expands the liquid crystal range to a high temperature range, and thus is suitable as, for example, an in-vehicle liquid crystal panel composition. Further, due to the large Δn, the reaction speed can be increased in STN (super twisted nematic) mode, and the contrast can be improved in PDLC (polymer dispersed liquid crystal) system and PNLC (polymer network liquid crystal) system.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tsutomu Ogihara 28, Nishi-Fukushima, Chugiki-mura, Nakakubiki-gun, Niigata Prefecture 1 Shinetsu Chemical Industry Co., Ltd. Synthetic Technology Laboratory (72) Inventor Go Kinsei Naka-Kijo, Niigata Prefecture 1 of 28, Nishi-Fukushima, Kubiki, Gun-gun, Shin-Etsu Chemical Co., Ltd., Synthetic Technology Laboratory (72) Inventor, Tatsushi Kaneko 1 of 28, Nishi-Fukushima, Kubiki-mura, Nakakubiki-gun, Niigata Shin-Etsu Chemical Co., Ltd. (72) Inventor Hideshi Kurihara 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Inside the corporate tracer center

Claims (8)

[Claims] 1. A silacyclohexane compound represented by the following general formula (I): [Chemical 1] However, R is a linear alkyl group having 1 to 10 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, and 3 to 3 carbon atoms.
It represents a branched alkyl group having 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. [Chemical 2] Is a trans-1-sila-1,4-cyclohexylene group or trans-4-sila-1,4-cyclohexylene group in which the silicon at the 1- or 4-position has a substituent of H, F, Cl or CH _3. Represent L ₁ and L ₂ each independently represent H or F. L ₃ and L ₄ are each independently H,
Represents F or Cl. X is H, CN, F, Cl, CF ₃ ,
CF ₂ Cl, CHFCl, OCF ₃ , OCF ₂ Cl, OC
HFCl, OCHF ₂ , a linear alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is represented. i represents 0, 1 or 2. 2. An organometallic reagent embedded image RM (M represents MgP (P represents halogen), ZnP or L)
represents i. ) And [Chemical 4] (Q represents a halogen, an alkoxy group, a methanesulfonyloxy group, a benzenesulfonyloxy group, a p-toluenesulfonyloxy group or a trifluoromethanesulfonyloxy group.) Or a carbon-carbon bond forming reaction or a carbon-
The method for producing a silacyclohexane compound according to claim 1, wherein the method is a silicon bond forming reaction. 3. An organometallic reagent (W represents H, F, Cl or CH ₃ ) and The method for producing a silacyclohexane compound according to claim 1, wherein the method is a carbon-carbon bond forming reaction with. 4. An organometallic reagent embedded image And [Chemical 8] The method for producing a silacyclohexane compound according to claim 1, wherein the carbon-carbon bond forming reaction with (wherein m and n are 0, 1 or 2 and satisfying m + n = 2). 5. An organometallic reagent And [Chemical 10] The method for producing a silacyclohexane compound according to claim 1, wherein the method is a carbon-carbon bond forming reaction with. 6. An organometallic reagent embedded image (M ′ is M, B (OR ′) ₂ (R ′ represents an alkyl group or a hydrogen atom) or TiP _k (OR ″) _3-k (P is a halogen, R ″ is an alkyl group, k is 0 to 0). Represents an integer of 3.)
Represents ) And [Chemical 12] The method for producing a silacyclohexane compound according to claim 1, wherein the method is a carbon-carbon bond forming reaction with. 7. A liquid crystal composition comprising the silacyclohexane compound according to claim 1. 8. A liquid crystal display device comprising the liquid crystal composition according to claim 7.