JPH03123736A - Method for cross-coupling by metal palladium catalyst - Google Patents

Abstract

PURPOSE: To obtain a compd. useful for liq. crystal, etc., by cross-coupling of an org. metal compd. with a halogen compd. or a perfluoroalkyl sulfonate by using metal Pd, which may be deposited on a carrier, as a transition metal catalyst.

CONSTITUTION: A compd. of formula IV is obtd. by cross-coupling of a compd. of formula I with a compd. of formula II, {where R¹, R² are each group of formula III [where R is alkyl, alkenyl, etc.; A¹, A² are each 1,4-phenylene, 1,4-cyclohexylene, etc.; Z¹ is single bond, COO, OCO, CH₂CH₂, CH=CH, etc.; (o), (p) are each 0-2, on the condition that (o+p)=2-4]; Z is single bond, alkylene, etc.; Met is Li, Na, K, ZnX (where X is halogen, alkyl, etc.); Y is halogen, OSO₂CnF_2n+1; E is ethylidene, etc.; (m) is 0, 1}, by using metal Pd which may be deposited on a carrier as the transition metal catalyst. The specified substance can be obtd. stereoselectively at a high yield.

COPYRIGHT: (C)1991,JPO

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a compound of the general formula (T) R'-Z-(El, -R" (1) "However, in this formula, ) An organometallic compound f of R1 (II) is produced by coupling with a compound of the general formula (III) Y-(E).-R2 (Ill) using a transition metal catalyst. However, in this formula, R1 and a halogen In the process for cross-coupling compounds or perfluoroalkyl sulfonates, the metal palladium as transition metal catalyst can be deposited on a support material, if necessary in the presence of a metal alcoholate. .

[Prior Art 1] All previously known methods for preparing the compounds of formula (I) above give unsatisfactory results. In particular, the yields are poor and this is due to the starting compounds, which are often difficult to obtain. That is, for example, 1-cyano-2-fluoro-4-(tr
Ans-4-heptylcyclohexyl)benzene can be prepared from the corresponding 1-acetyl compound by the method of EP 0.119.756 with a yield of only about 1% of theory.

Furthermore, 1-fluoro-2-(trans-4
-alkylcyclohexyl) compounds also require significant synthetic effort, and the desired compounds occur only in unsatisfactory yields.

The use of P d (II) arylphosphine complexes bound to polymers in header coupling reactions, which are only slightly leached by the reaction medium after being reduced to the corresponding P d (0) complexes, has been investigated. [R,F, Heck:”Org, React
ions (N, Y,)” 27.345 (1982)
-lalIberg by Anderson
etc.: -J, Org, Chem, -50,38
91 (+9851 and Teranishi et al.:
"J, 0"ganomet.

Chem,” 162.403’ (1978)],
According to this reaction, various aryl iodides can be coupled with styrene compounds and acrylates in the presence of a Pd phosphine catalyst bonded to a carrier. Aryl bromides react very poorly or not at all with these catalyst systems. That is, in the reaction of bromobenzene and methyl acrylate at 100°C, 80
It takes as long as 6 days to reach % conversion.
rg, Chem,” 50.3891 (1985)
3894 et seq.], Bromobenzene reacts with styrene to produce only traces of stilbene, J. Organo.
met, Chem,” 162.403 (1978
) Page 410 et seq. 1 However, iodobenzene gives 86% of the various isomers of stilbene after 2 hours.

Although Pd/C is one suitable catalyst for the hexagonal coupling of iodobenzene, this catalyst system is no longer suitable when using bromobenzene. Not only in Herafu coupling, but also in Kumada/Negishi coupling [for example, umada etc.: "J, Am.

Chem, Soc,” +06.158 (1
984), Negishi: -Acc.

Chem, Res,” 15.340 (1982)
, German Patent No. 3632410 and German Patent No. 373648
No. 9, E. Poetsch: “Kontakt
e-(Darmstadt') 1988 (2) 15
-28 and the references cited therein], the oxidative addition product Ar-PdLz-Br formed from the Pd(0) compound pdL, (L represents a ligand) and bromobenzene. is also one of the reactive yarn compounds, so those skilled in the art had to judge that metallic Pd is not very suitable for the Kumada/Negishi coupling reaction of bromobenzene compounds. Since Kumada/Negishi coupling is carried out under significantly milder conditions than Hetsu coupling, most of the aryl iodides and metal Pd due to the relatively unstable metal derivatives used.
A Kumada/Negishika ring using ``and'' cannot be expected to be successful.

Since the cross-coupling of β-bromostyrene and methylmagnesium iodide catalyzed by Pd(0) due to the presence of a phosphine ligand attached to the polymer was described in 1978, it has been The cross-coupling of bromobenzene with 3-chloro-2-methylphenylmagnesium chloride has been described only once to date (European Patent Application Publication Box 0.152.4
50) can only be explained by this.

[Problem to be Solved by the Invention] The object of the invention is to find a process for the preparation of the compounds of formula (I), which does not exhibit any or only a few of the disadvantages of the conventional processes mentioned above. be.

[Means for Solving the Problems l] Surprisingly, the inventors have discovered that in order to produce the compound of formula (I), various methods are used in the presence of metallic palladium, which may be deposited on a carrier. It has been found that the organometallic compounds of

Therefore, the present invention provides the formula (II) using a transition metal catalyst.
In preparing the compound of the formula (I) by coupling the organometallic compound of A method characterized in that:

Although some of the compounds of formula (1) are known, some others are new compounds. The invention therefore also relates to this new compound of formula CI).

Conventionally known C-
In the C coupling reaction, β-elimination from the C)I group adjacent to the coupling position, during the preparation of the organometallic compound or from the organometallic compound itself, has a strong influence on the steric process and the yield. Stereoselective coupling of aliphatic or aromatic organometallic compounds with aromatic, heteroaromatic, aliphatic or cycloaliphatic halogen compounds or sulfonates, taking into account that it occurs as a side reaction to give It was all the more surprising that this was even possible.

Furthermore, the process has been found to be highly chemoselective such that even electrophilic groups such as esters and nitriles cannot interfere with the reaction process. Moreover, the metallic palladium formed when the reaction is completed can be easily separated and removed, so that no contaminants enter the wastewater. If desired, the metals can be varied, thereby making it possible to selectively influence the chemoselectivity, stereoselectivity and enantioselectivity of each compound of formula (II), and to It will be possible to adjust to each special condition.

The starting material for the process according to the invention is of the following formula (V)R-(A
'-Z')o-(Ax)p-Z-Y' (v
), in which R,
A', A', Z, Z', o and U p have the same meanings as given for formulas (I) and (II), and Y' is chlorine, bromine, iodine, easily removable. represents a hydrogen atom or a vinyl group that can be easily converted into a metal ethylene group.

These compounds can be prepared by formula (II) by various known methods.
) can be converted into the corresponding organometallic compound. The method used is preferably tailored to the nature of the functional groups present in the metallizable compound of formula (rv).

Thus, for example, zinc derivatives are
From org Thieme Verlag 197
Iouben-Weyl's ＋
Method of development
Chemie” Volume XIII/2a “Processes for the Preparation and Conversion of Organozinc Compounds” or by Lucke et al.
J, Org, Chem,” 50.4761 (19
851, the boron compounds are made in accordance with, for example, H, C,
The method of Brown et al.
tters” 29.2631 (+988): Alkynyl diisopropyl boronate, “J, Am.

Chem, Sac,” 104.4303 (198
2): xyl 2-butyl dimethyl boronate, -Koga
nometa l ics''.

+788 (1985): Boronates and pollinates, -OrganometaIIics-g,
1316 (1983): Boronates and Boronic Acids]
made by. The aluminum compound is, for example, Ne
gtshi et al.: -J, Am, Chem.

Soc,” 109.2393 (1987) or 0hta etc.: “1leterocycles-
26, 2449 (1987), and zirconium compounds are made by, for example,
Chem, Int, Ed, Engl,
” 25,508 (+986), and titanium compounds are described, for example, by Reetz: “Top, Curr.
, Chem, -106, 1 (1982).

The reaction of the metallizable compound of formula (rv) (Y'=chlorine, bromine or iodine) is preferably carried out with ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran or dioxane, such as hexane, cyclohexane,
Lithium metal, n
-butyllithium, tert-butyllithium, lithium naphthalenide, lithium di-tert-butylnaphthalenide or metallic magnesium from -100' to +
It is carried out at temperatures up to 100°C, preferably from -78° to +75°C.

The deprotonation of the metallizable compound of formula (V) (Y'=H) is preferably performed with hydrocarbons such as pentane, hexane, cyclohexane, benzene or toluene,
Lithium diisopropylamide, lithium dicyclohexylamide, lithium bis( -100 by a lithium amide such as trimethylsilyl)amide or lithium tetramethylpiperidine.
° to +100℃, preferably from -78m to +7
It is carried out at temperatures up to 5°C.

Conversion of the metallizable compound of formula (IV) to an organolithium compound or a halogenoorganomagnesium compound (Y' = Li or MgX) under such conditions usually involves
Complete in about 10 to 60 minutes.

A metal compound of the formula (v r ) Met-
In this formula, X' is independently CI %B
r, R', OR' or NR'2, in which case RB
has the meaning already given) by adding
The organometallic compound is obtained after a reaction time of typically 180 minutes.

The metal compound of formula (VI) can be added in dissolved or undissolved form.

Generally they are added in dissolved form, preferably in the same medium in which the halogenoorganomagnesium compound or organolithium compound is present. A coupling moiety of formula (III) and metallic palladium, optionally precipitated on a support, are added to the solution, resulting in selective coupling to give a compound of formula (I).

Preferably, the same solvents as mentioned above for the preparation of the organometallic compound of formula (II) are used at the temperatures mentioned. Generally the reaction time required is about 1 hour and 10
It is between 0 hours.

In one of the preferred embodiments of the method of the invention, the formula (
II A compound of formula (III) is added to the organometallic compound of I) together with metallic palladium and a metal alcoholate in an inert solvent. Preferred metal alcoholates are, for example, sodium methoxide, sodium ethoxide, sodium isopropoxide, potassium tert-butoxide.

The starting compounds used are a metallizable compound of formula (V) and a compound of (III). Suitable halogen compounds that can be used are all halides which can be converted into organometallic compounds. Preferably, bromide is used, and also chloride and iodide.

The formulas (Va) to Vk) listed below are a group of particularly very preferred starting compounds, in which each aromatic group can be substituted by F, C1, CN or CH, and The cyclohexyl group can be substituted in one position by F, CI, CF2, CN or a C1 to C4 alkyl group.

RI-3r Va R'-0-Br %Il+ 8.-〇Fuku　　　　　　.

(Left below) R'-0-01tGIJr VdR'-0-0-
Br Ve Ht-0-07-Ivt R1-〇-〇-GItG1. Br VgR'-@-B
r vh R'-@-(21tQlt-Br viR'-@
-@-Br Vk In these formulas, R1 is preferably an alkyl group of 1 to 18 carbon atoms, of which one or two non-adjacent C1+□ groups are also -0 and/or - C.O.
- and/or -CO-0-, in formulas (I), ([I), (III I) and (IV), R', R'' and R are 1 to 18; Preferably 2
Preference is given to straight-chain or branched alkyl of from 1 to 10 carbon atoms, thus preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl, but also methyl, undecyl. , dodecyl, tridecyl, tetradecyl or pentadecyl. For example, isopropyl, 2-
Branching groups such as butyl, isopentyl, 1-methylpentyl, 2-methylpentyl, 1-methylhexyl or 1-methylheptyl are also preferred.

R1 and R2 are preferably also ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, tunoxy and decoxy, and also methoxy, undecoxy, dodecoxy, tridecoxy, tetradecyl or pentadecyl, or also isopropoxy, isopentoxy, 2 -butoxy or 1-methylpentoxy is also preferred.

All compounds of formula (I II I) can be used for coupling with organometallic compounds of formula (II). Preference is given to using bromide (Y = Br), and also chloride (Y = CI) and perfluoroalkanesulfonates (y = oso□-(CF2), -CF, ). Among the perfluoroalkanesulfonates Particular preference is given to trifluoromethane, perfluoroethane and perfluoropropanesulfonates; iodides (Y=1) are particularly suitable for coupling branched aliphatic compounds of formula (III) with organotitanium compounds.

The following (I I I a) or I I I
The formula v) represents a group of particularly very preferred starting compounds, in which each aromatic group is F, CI, CN
or CHs, and the cyclohexyl group is substituted in one position by F, CI, C
It can be substituted with Fs, CN or C, -C4 alkyl groups.

Br-@-0CF, IIIaBr-@-Il
al (Ilal 1.t/1.ke, llIbBr
-@-(7) 1Ic Br-@-Ql Ir[d Br-@-11" IIe Br-@-@-R' 1If Br-@-传-R2 11g Br-@-@-012alt-@-R 'tnhBr
-@-〇+2Of, -@-R' lH45r-@-a
+-o+-@-@-v mjBr-@-a+, a+*
-@-Tawara-r rlIkBr-R”
III-0-R' +1Th x@@-n□ 1Tn Br-01-GIm-O-R" rlI.

“’P” HI.

Br-@-ωt-@-R' Hlr Br-@-1ffl, -0-R" oreBr-CI
l, -Go, -R'' IIIv In these formulas, R2 is preferably a furkyl group of 1 to 15 carbon atoms, in which one or two non-adjacent CI+
□ Group is 10- and/or -C〇- and/or -CO-0
- can be replaced by

In particular, metal halides or metal oxides are suitable as metal compounds of formula (Vt). Mixed herrogenometal alkoxides are also suitable in the case of polyvalent metals.

Particularly preferred metal compounds of formula (V I ) are shown below (V
It is that of formula Ia) to VII).

B(OR″)s Vla BCI (OR') 2VIb BCl2 VIC AICI (R') z VIdAICI3
Vle CITi (OR') s VIfBrTi
(OR') s V1gTiCI4Vlh CITi (NR'z) s VTiCIZr
(OR5)s VIjHgCh
VIk CISnR', Vll Preferably used metal catalysts are metal Pd [i.e. Pd(0)1, palladium on activated carbon (i.e. Pd
/C) in which the ratio of palladium to activated carbon is 1 to 99% by weight, preferably 1 to 10% by weight,
and palladium on barium sulfate (Pd/BaO,
). The halogen compounds of formula (IV) used as starting compounds are known or can be prepared, for example, by the +Method of Houben-Weyl described above.
n der organischen Chemie+
It can be made by the known method described in Volumes 573 and 574. For example, Xo
Alcohols of formula (IV) in which is a hydroxyl group are 3
It can be converted to the corresponding halide by phosphorus halide or triphenylphosphine/4-halogenated carbon.

The metal compound of formula (VI) used as a transmetallation agent is a known one or, for example, Gmel.
It can be made by the known method listed in the handbook of the author.

The compounds of formula (III) used as coupling components are also known or can be obtained by known methods.

For example, a halide of the formula Hr B in which X is Br or ■, n is 0 and Q is an aromatic group can be obtained by replacing the diazonium group of a suitable diazonium salt with B or ■.

Formula (III) i, x at 1 m is 0SOz-(CFa)
Perfluoroalkyl sulfonate compounds of -CFs can be made by esterifying the corresponding alcohol of formula (I II I) in which X is a hydroxyl group with perfluoroalkanesulfonic acid or a reactive derivative thereof. Corresponding perfluoroalkanesulfonic acids are known.

Suitable reactive derivatives of the abovementioned perfluoroalkanesulfonic acids are especially their acid halides, especially the chlorides and bromides, and also, for example, mixed acid anhydrides, azides or esters, especially those containing 1 to 4 atoms in the alkyl group. Also suitable are alkyl esters having carbon atoms of .

The invention thus provides a highly advantageous process for the simple stereoselective preparation of compounds of formula (I) which proceeds in high yields.

Compounds of formula (1) are disclosed, for example, in German Patent Box 3, 217.
597 and 2.636.684, or can also be used as an intermediate compound for the production of further liquid crystal compounds. .

[Example 1] Specific examples of the present invention are given below, but these are merely for detailed explanation without imposing any limitations on the present invention. In these examples m, p are melting points, c,
p represents a clearing point, C represents a crystalline state, N represents a nematic state, and ■ represents an isotropic state, respectively. In 1 or more and below, all % values are weight % values.

In the examples given below, "conducting normal operations" means adding weakly acidified water, extracting with toluene, drying the organic phase, evaporating and purifying by chromatography or crystallization. do.

IA 4°-pentylbiphenyl-4-yl-boronic acid 4-bromomagnesium-4°-pentylbiphenyl (
150 g of 4-bromo-4°-pentylbiphenyl and 1
0.8g of magnesium) and 450ml
of tetrahydrofuran is slowly added to a solution of 156 g of triisopropyl borate in 100 ml of tetrahydrofuran at -70'C. After the temperature has risen to 20° C., 650 ml of 10% strength hydrochloric acid solution are added to the reaction mixture. The aqueous phase is separated off and washed with water;
After drying, the boronic acid is obtained, which can be used in the next step without further purification.

1B 4"-pentyl-4-cyano-p-terphenyl 5.4 g of the boronic acid of IA above, 3.7 g of 4-bromobenzonitrile, 50 ml of toluene, and 15 m
In a mixture of 4.2 g of sodium carbonate in 1 part of water,
0.658 Pd/C (10%) is added and the mixture is stirred at room temperature for 24 hours and heated to the boil for 15 minutes. After customary work-up and purification by chromatography, 3.0 g of the above terphenyl are obtained. m, f), “130°C, c, p, = 239°C.

Similarly, the following 4"-alkyl-4-cyano-p-terphenyl compound is obtained: Alk-@-■-@-01(Ath (!7Jt, #J
I4) 1 A Bis(4°-pentylbiphenyl-4-yl)-boronic acid This is prepared analogously to Example LA above from: 4-bromo 4′-pentylbiphenyl: t50 g Magnesium: 10.8 g boric acid Triisopropyl, Nia 8g and 4”~Benchru 4
-cyano p-terphenyl This is prepared analogously to Example IA above from: 2A above.
Compound: 1.2g 4-10mobenzonitrile: 0.74g NazCO3: 0.42g Water 5
m1Pd/C (10%) + 0.
0.7 g of the above terphenyl compound is obtained by carrying out the usual operations and purification.

[ 3A n-Butylboronic acid This is prepared analogously to Example IA above from: n-butyllithium (10M solution in hexane): 3.3 ml Trimethyl borate: 6.3 g 3B 4- (t
rans -4-propylcyclohexyl)-4°-butylbiphenyl This is prepared analogously to Example IB above from: 3A above.
Compound +5.0gPd/C (10%)
:0.7g4- (trans-4-
Propylcyclohexyl-4-bromobiphenyl: 18. Conventional work-up and chromatographic purification gives the product as a colorless solid.

The following 4°-(4-trans-alkylcyclohexyl)-4-alkylbiphenyl compounds are prepared in a similar manner: Takumi A 4A 8.6 g of cis-4-(trans-4'-propylcyclohexyl)-bromocyclohexane (made from the corresponding trans-alcohol using triphenylphosphine/element in acetonitrile in a known manner for the bromination of alcohols) in 3.4 g of zinc bromide and 0.42 g of lithium disks. 50m including finely ground material
The reaction is carried out in a cooled ultrasonic bath in a mixed solvent of 1:1 toluene/tetrahydrofuran (4:1) until no more lithium is detected. This reaction mixture contains 196
g of palladium/activated carbon (10%) and 6 g of 4-bromo-2-fluorobenzonitrile are added, this is stirred at room temperature for 18 hours, and then lightly acidified water is added which is heated to boiling water for 15 minutes. , the product is extracted with toluene, the organic phase is dried over Mg5Oa and evaporated. Evaporation residue to petroleum ether/
Chromatographic purification on silica gel using diethyl ether 9:1 eluent and crystallization from ethanol gave 7.7 g of 4-cyano-3-fluoro-
1-[trans-4'-(trans-4"-propylcyclohexyl)cyclohexyl]benzene is obtained. m, p, = 54.3°C, c, p, = 203
℃.

Similarly, 6.06 g of cis-4-(trans-
From 4°-butylcyclohexyl)bromocyclohexane and 5.4 g of 4-trifluoromethanesulfonyloxy-2-fluorobenzonitrile, 2.3 g of 4-cyano-3-fluoro-1-(trans-4°-(7ra
ns-4''-butylcyclohexyl)-cyclohexyl]benzene is obtained.

Transition temperature: C/N=67°C, N/I=197.4°C.

In the same way, the following compounds can be produced. List the (C/N) crystalline state/nematic state transition temperature and (N/I) nematic state/isotropic transition temperature in Table 1. be.

Saturday 4- [trans-4”-(trans-
4”-alkylcyclohexyl)cyclohexyl]-halogenobenzene^1-Q-〇-@-11al 8(k-〇-〇-0-R4 C 4-[trans-4°-(trans-4”-alkylcyclohexyl) )cyclohexyl]benzene derivative (1゛J margin) D 4- [trans-4'-(trans-4'
.

-alkylcyclohexyl)cyclohexyl]halogenobenze 4 E trans-4-alkylcyclohexylaryl derivative example j- 5A 4-propylphenylboronic acid This is prepared analogously to Example IA above from: 4-bromopropylbenzene, 96 g magnesium :0.98g trimethyl borate
:4.15g and 4- (trans-4-
pentylcyclohexyl)-4°-propylbiphenyl Compound 5A above, prepared analogously to Example IB above from :
4.2g water
+2.5m1Pd/C (10%)
: 0.65 g of the above biphenyl derivative 5 after the usual operation and purification by chromatography.
．． 5 g are obtained as a colorless solid.

6A 4-Trifluoromethoxy-4°-propylbiphenyl This is made analogously to Example 5B above from: Compound 5A above: 1.65g 4-Trifluoromethoxybromobenzene: 2.5g Toluene
:25 ml water
:15 m1Naz
COs: 1. 1
gPd/C (l 0%): 0.3
After carrying out the usual work-up and purification by chromatography, 1.8 g of the trifluoromethoxybiphenyl derivative described above are obtained.

Dish Uni A 4-Trifluoromethoxy-4'-bromobiphenyl First 92 ml of a 15% strength solution of n-butyllithium in hexane and then 18.8 g of ZnBrz
and 100 ml of tetrahydrofuran at -7
36 in 100 ml of tetrahydrofuran at 0°C
．． Add to the mixture 4 g of 4-trifluoromethoxy-4°-bromobenzene.

43.4 g of 1-bromo-4-iodobenzene and 8.8 g of Pd/C (10%) are added to the reaction mixture.

After stirring for 24 hours, usual work-up and purification by chromatography gives 23.-9 g of trifluoromethoxybiphenyl.

Takugou 8A p-vinylpropylbenzene This is made from: p-propylbromobenzene: 60g magnesium
: 7.3g zinc bromide
: 33.8g tetrahydrofuran
:500 ml bromoethylene :
35 gPd/C (10%):
6.4g sodium methoxide: 0.16
gp-propylphenylzinc bromide (prepared using the corresponding Grignard reagent) is reacted with a mixture of bromoethylene, Pd/C and sodium methoxide at room temperature, followed by normal manipulation and purification by chromatography. 37.0 g of product 8A are obtained.

4-(trans, trans-4'-pentylbicyclohexyl-4-yl)-2-fluorobenzonitrile This is prepared analogously to Example 4 above from: 4°-pentyl-4-bromobi Cyclohexane: 6.4g zinc bromide
:2.3g lithium
+0.28g THF/toluene (1:4)
: 50 m14-Bromo-2-fluorobenzonitrile: 4.0 g Pd Catalyst: (listed in the table) Metal alcoholate: (listed in the table) Perform normal operations,
After purification by chromatography, the above products are obtained in the respective yields listed in Table I below.

Table I Takumi Yukidan A 4-(trans, trans-4'-pentylbicyclohexyl-4-yl)-1-1-lifluoromethoxybenzene This is made analogously to Example 4 above from: 4 -Pentyl-4-bromobicyclohexane: 6.4g zinc bromide
:2.3g lithium
: 0.28gTHF/toluene (1:4)
:50 mlp-trifluoromethoxybromobenzene =5g Pd/C (10%) : 0.42g
Sodium methoxide: 0.02 g Following normal operation, 8.9 g of the above product are obtained.

Takumi Doko 1 Work A 4-phenylnicotinic acid This is made from the following: Benzene boronic acid + 3.7 g 4-bromonicotinic acid: 6.1 g 1 hO: 50 ml Na2COs: 9.6
gPd/C (10%): 1.6 g After the usual working-up, 3.5 g of the above product are obtained analogously to Example 1.

Milrinone 1 was similarly prepared by reacting 2.4-dimethyl-5-methoxy-4-cyano-3-bromopyridine with pyridin-4-yl-boronic acid, followed by acid hydrolysis of the methoxy group with hydrochloric acid. obtained [W, J, Thompson
: “J.

Org, Chem,” Nezumi, 2052-2055
(1988) ).

Claims (1)

[Claims] 1. Compound of general formula (I) R^1-Z-(E)_m-R^2 (I) However, in this formula, R^1 and R^2 each independently represent The group R-(A^1-Z^1)_o-(A^2)_p(IV)[ of the following formula (IV)
provided that R are independently of each other an alkyl or alkenyl group each having up to 18 carbon atoms, which is unsubstituted or substituted by CN or at least one halogen; The above non-adjacent CH_2 groups are -O-, -S-, -CO-, -O-CO
-, -CO-O- and -C≡C-, one of the above groups being halogen, -NC, -CF_3, -CN
or -OCF_3, where A^1 and A^2 are each independently a) 1,4-phenylene group, of which one or two
(b) A 1,4-cyclohexylene group in which one or two non-adjacent CH groups are -O- or -S- or c) 1,4-cyclohexenylene, piperidine-1,4
-diyl, 1,4-bicyclo[2.2.2]octylene or naphthalene-2,6-diyl radicals, in which case for the groups a) and b) these are halogen atoms, cyano groups and/or methyl They may be mono- or polysubstituted by the group, and Z^1 independently represents -CO-O-, -O-CO-, -CH_2CH_2-,
-CH(CN)-CH_2-, -CH_2-CH(CN
)-, -CH=CH-, -OCH_2-, -CH_2O
-, -CH=N-, -N=CH-, -NO=N-, -N
=NO-, -N=N- or a single bond, o and p are each independently 0, 1 or 2, and the total sum of o and p is 2, 3 or 4. ], Z is a single bond or an alkylene group of 1 to 4 carbon atoms, which is unsubstituted or substituted with CN or halogen, and E is unsubstituted or is substituted with CN or halogen. and m is 0 or 1. is an organometallic compound of the general formula (II) R^1-Z-Met(II) where R^1 and Z have the same meanings as above, and Met is Li, Na, K, ZnX, B(X )_2, Al(X)_
2, Ti(X)_3, Zr(X)_3, HgX or Sn
X_3, where each X is independently R
a group of the formula ^1-Z-, a halogen, an alkyl or alkoxy group of 1 to 6 carbon atoms, or a cyclopentadienyl group, in which case when Met is B(X)_2, X is It can also be OH. and a compound of general formula (III) Y-(E)_m-R^2(III) where E, R^2 and m have the same meanings as above, and Y is halogen or OSO_2-C_nF_2_n_+_1, where n is an integer from 1 to 10. A process for the cross-coupling of an organometallic compound and a halogen compound or perfluoroalkyl sulfonate for the preparation by coupling with a transition metal catalyst, even if the transition metal catalyst is deposited on a support material. The above method, characterized in that palladium is a good metal.