CN1293084C

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Publication number: CN1293084C
Application number: CNB200410020835XA
Authority: CN
Inventors: 何仁; 郭孟萍; 周丽
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2004-06-25
Filing date: 2004-06-25
Publication date: 2007-01-03
Anticipated expiration: 2024-06-25
Also published as: CN1594333A

Abstract

本发明属于精细化工技术领域，提供一种催化交叉偶联反应的催化剂制备方法和实施催化反应的技术。所指的催化剂是二苯基膦乙酸钯型配合物，它制备方法简便、活性高、选择性好、在空气中稳定；交叉偶联反应的特征是能在室温或稍高温度、常压、碱性条件下，水/有机两相中由二苯基膦乙酸钯型配合物催化芳香族溴代物与芳香族硼酸间的交叉偶联反应，生成联苯型化合物，特别是联苯型TFT-LCD用液晶化合物，产率高。产物与催化剂通过简单相分离即可分开，催化剂可循环使用。本发明提供了合成联苯型TFT-LCD用液晶化合物的绿色化学方法。The invention belongs to the technical field of fine chemicals and provides a catalyst preparation method for catalyzing cross-coupling reactions and a technology for implementing catalytic reactions. The catalyst referred to is diphenylphosphine acetate palladium type complex, and its preparation method is simple, and activity is high, and selectivity is good, stable in air; Under alkaline conditions, the cross-coupling reaction between aromatic bromide and aromatic boronic acid is catalyzed by diphenylphosphine acetate palladium complex in water/organic two-phase to generate biphenyl compounds, especially biphenyl TFT- Liquid crystal compound for LCD with high yield. The product and the catalyst can be separated by simple phase separation, and the catalyst can be recycled. The invention provides a green chemical method for synthesizing liquid crystal compounds for biphenyl type TFT-LCD.

Description

Method for synthesizing liquid crystal compound by catalytic cross-coupling of palladium diphenylphosphinoacetate

Technical Field

The invention belongs to the technical field of fine chemical engineering and material chemistry, and relates to a liquid crystal compound for synthesizing a TFT-LCD (thin film transistor-liquid crystal display), in particular to a greening technology for synthesizing the liquid crystal compound by using a coordination catalysis method.

Background

Many biarylenes have liquid crystalline properties and have been used in TFT-LCDs. The biaryl compound prepared by the classical organic synthesis method has long route, low total yield, poor selectivity and serious pollution. The coordination catalysis has the advantages of mild reaction conditions, good selectivity and the like, and provides an important means for greening organic synthesis. The coordination catalysis method is mostly adopted for the green chemical industry accepted by the world at present.

Coupling reactions catalyzed by the zero-valent palladium complex, such as Heck reaction, Suzuki reaction, Stille reaction, Sonogashira reaction, Tsuji-Trost reaction and the like,are effective methods for forming C-C bonds in organic synthesis. Among them, Pd (PPh) was discovered by Suzuki in 1981₃)₄The method for preparing asymmetric diaryl or polyaromatic hydrocarbon by catalyzing the cross coupling of aromatic bromide and aromatic boric acid forms C_SP2--C_SP2One of the important methods for aromatic bonding.

Diphenylphosphinoacetic acid has been used as ligand in SHOP process for synthesizing linear α -olefin by oligomerization of ethylene, it, nickel chloride and sodium borohydride form a catalytic system to catalyze the oligomerization of ethylene in 1, 4-butanediol solution [ USP3,686,351 Shell Dev. Co., 1972.1.18], it and bis-1, 5 cyclooctadiene nickel form a catalytic system to catalyze the isomerization of α -olefin double bond [ Ger. Offen 2,120,977 Shell International research, 18, Nov 1971].

Branstein, p. et al report the synthesis of palladium diphenylphosphinoacetate. 2mmol of sodium diphenylphosphinoacetate were suspended in CH at room temperature₂Cl₂In (1 mmol of PdCl is added₂(PhCN)₂. Reaction ofThe reaction time is 4 hours,obtaining the earthy yellow cis-Pd (Ph)₂PCH₂COO)₂43% yield [ Braunstein, P., Matt, D., Nobel, D., J.Organomet. chem., 301(1986)]401-]。

Buchecker, r. catalyzed cross-coupling of 4-bromobenzaldehyde and 4-fluorobenzeneboronic acid to synthesize 4-fluoro, 4-formylbiphenyl liquid crystal compound with 5% palladium on carbon in alkaline condition and benzene/ethanol mixed solvent, yield 93.2% [ DE 4,307,243(Hoffmann La Roche, f., und co.a-G1993]. Herrmann, w. catalyzed cross-coupling of 2-bromobenzonitrile and phenylboronic acid in toluene solution in the presence of potassium carbonate to obtain 2-cyanobiphenyl, yield 93% [ EP 690,046, Hoechst ag, 1996].

Disclosure of Invention

The invention aims to provide a catalyst and a method for synthesizing a biphenyl type liquid crystal compound for TFT-LCD by catalytic cross-coupling reaction.

Technical scheme of the invention

1. Catalyst synthesis method

At room temperature, Ph₂PCH₂Adding Na dropwise into COONa solution₄PdCl₄In the solution, a yellow precipitate is obtained, see reaction formula (1).

2. Cross-coupling reaction

The reaction is carried out at room temperature in a two-phase aqueous/organic phase, see equation (2).

The invention has the advantages that:

1. the catalyst has simple preparation method, high activity, good selectivity and stability in air.

2. The cross-coupling reaction is catalyzed in two phases of room temperature or slightly higher reaction temperature, normal pressure, alkalinity and water/organic phase, the reaction condition is mild, and the selectivity is good.

3. The reaction products are in the organic phase and the catalyst is in the aqueous phase, which can be separated by simple phase separation, and the catalyst in the aqueous phase can be recycled. The reaction is carried out in two phases but the use of a phase transfer agent is not necessary.

Detailed Description

EXAMPLE 1 preparation of catalyst

A ground plug with a crescent piston is arranged on one side port of the 100ml three-mouth flask and is connected with ultra-pure nitrogen. The other side opening is provided with a constant pressure dropping funnel. The flask was fitted with a stirring magnet and then stoppered, and the flask was mounted on a magnetic stirrer. The whole set of the apparatus is evacuated and filled with nitrogen for three times, and the subsequent operation is carried out according to the method for treating sensitive substances in the air.

1mmol of N was added under stirring at room temperature₄PdCl₄Dissolved in 10ml of deoxygenated water; 2mmol Ph was added to a constant pressure dropping funnel₂PCH₂COONa dissolved in 5ml deoxygenated water. Ph is₂PCH₂Adding Na dropwise into COONa solution₄PdCl₄In the solution, a yellowish brown precipitate rapidly formed, and stirring was continued for 10 min. Filter pressing and vacuum drying to obtain the product with the yield of 93 percent.

EXAMPLE 2 Synthesis of biphenyl type Compound

A ground plug with a crescent piston is arranged on one side port of the 50ml two-port flask and is connected with ultra-pure nitrogen. The flask was fitted with a stirring magnet and then stoppered, and the flask was mounted on a magnetic stirrer. The whole set of the apparatus is evacuated and filled with nitrogen for three times, and the subsequent operation is carried out according to the method for treating sensitive substances in the air.

5ml of deoxygenated water and 5ml of tetrahydrofuran were placed in a two-neck flask. 1.0mmol of aromatic bromide, 1.5mmol of arylboronic acid, 3.0mmol of potassium phosphate and 0.02mmol of catalyst are added into a bottle in sequence and stirred for a certain time at room temperature. The reaction mixture is extracted with ether or ethyl acetate, the lower layer is water-soluble of the catalystThe liquid can be reused after being separated. Washing the upper layer of extract with saturated NaCl solution, and Mg₂SO₄Drying, filtering and evaporating the solvent. The obtained product is subjected to column chromatographyPurifying by a method, wherein a developing agent is n-hexane and ethyl acetate which are 7: 1, and obtaining the product. The results are shown in Table 1

TABLE 1cis-Pd (Ph)₂PCH₂COO)₂Catalytic cross-coupling synthesis of biphenyl compound

Note: isolated yields are shown in the table.

Example 3

One side port of the 100ml two-port flask is provided with a ground plug with a crescent piston and is connected with ultra-pure nitrogen. The flask was fitted with a stirring magnet and then stoppered, and the flask was mounted on a magnetic stirrer. The whole set of the apparatus is evacuated and filled with nitrogen for three times, and the subsequent operation is carried out according to the method for treating sensitive substances in the air.

20ml of deoxygenated water and 20ml of tetrahydrofuran were added to a two-neck flask, 5.0mmol of aromatic bromide, 7.5mmol of aromatic boric acid, 15mmol of potassium phosphate and 0.05mmol of catalyst were sequentially added to the flask, and the mixture was stirred at room temperature for a certain period of time. The reaction mixture is extracted with ether or ethyl acetate, the lower layer is the aqueous solution of the catalyst, and the catalyst can be reused after being separated. The upper layer was washed with saturated NaCl solution, dried over Mg2SO4, filtered and the solvent was evaporated. Purifying the obtained product by column chromatography, wherein the developing agent is n-hexane and ethyl acetate which are 7: 1, and obtaining the product. The results are shown in Table 2

TABLE 2cis-Pd (Ph)₂PCH₂COO)₂Liquid crystal compound for synthesizing TFT-LCD (thin film transistor-liquid crystal display) by catalytic cross-coupling

Note: isolated yields are shown in the table.

Example 4 catalyst reuse

50ml of deoxygenated water and 50ml of tetrahydrofuran were added to a two-necked flask, and 10.0mmol of 4-propyl- (4' -cyclohexyl) -bromobenzene, 15.0mmol of 4-fluorobenzeneboronic acid, 30mmol of potassium phosphate and 0.1mmol of catalyst were sequentially added to the flask, and the mixture was stirred at 70 ℃ for 4 hours without precipitation of palladium black. The reaction mixture is extracted with toluene or ether, the lower layer is the aqueous solution of the catalyst, and the catalyst can be reused after being separated. Washing the upper layer of extract with saturated NaCl solution, and Mg₂SO₄Drying, filtering and evaporating the solvent. The obtained product is purified by column chromatography, the developing agent is n-hexane and ethyl acetate which are 7: 1, and the separation yield is 84%.

The instrument was mounted and handled as described above. Adding the catalyst separated from the previous experiment into a two-neck flaskThe aqueous solution was supplemented with 50ml of tetrahydrofuran. 10.0mmol of 4-propyl- (4' -cyclohexyl) -bromobenzene, 15.0mmol of 4-fluorobenzeneboronic acid, 30mmol of potassium phosphate and 0.1mmol of catalyst were added in succession to a bottle and stirred at 70 ℃ for 4 h. The reaction mixture is extracted with toluene or diethyl ether and the lower catalyst aqueous solution is separated. Washing the upper layer of extract with saturated NaCl solution, and Mg₂SO₄Drying, filtering and evaporating the solvent. The obtained product was purified by column chromatography with a developing solvent of n-hexane and ethyl acetate of 7: 1, isolated in 93% yield.

Claims

Translated fromChinese

1.二苯基膦乙酸钯催化交叉偶联合成液晶化合物的方法，其特征是：二苯基膦乙酸钯型配合物催化芳香族溴代物与芳香族硼酸间的交叉偶联反应，生成联苯型TFT-LCD用液晶化合物；交叉偶联反应在室温、常压，碱性条件下，在水/有机两相中进行；反应后经乙醚或乙酸乙酯或甲苯萃取后，产物在上层，催化剂在下层，通过相分离就可分开；蒸干上层物料中溶剂，得到产物，通过柱色层分离得到纯净的产物；下层催化剂水溶液可重新催化该反应；1. The method for synthesizing liquid crystal compound by palladium diphenylphosphine acetate catalyzed cross-coupling is characterized in that: the cross-coupling reaction between aromatic bromide and aromatic boric acid catalyzed by diphenylphosphine acetate palladium type complex generates biphenyl Type TFT-LCD liquid crystal compound; the cross-coupling reaction is carried out in water/organic two-phase at room temperature, normal pressure, and alkaline conditions; after the reaction is extracted with ether or ethyl acetate or toluene, the product is in the upper layer, and the catalyst In the lower layer, it can be separated by phase separation; the solvent in the upper layer is evaporated to dryness to obtain the product, and the pure product is obtained by column chromatography; the aqueous catalyst solution in the lower layer can re-catalyze the reaction;

(1)所指的芳香族溴代物，是溴苯的邻、对位被R基取代的衍生物，R是氢、1-12碳的直链烷基、烷氧基、羰基、氟、环己烷基衍生物；(1) The aromatic bromide referred to is a derivative of the o- and para-position of bromobenzene substituted by the R group, and R is hydrogen, a straight-chain alkyl group with 1-12 carbons, an alkoxyl group, a carbonyl group, fluorine, a ring Hexyl derivatives;

(2)所指的芳香族硼酸，是苯硼酸被R基取代的衍生物；R是氢、邻或对位1-12碳的直链烷基、烷氧基、羰基、4-正丙基-环己基、4-氟、3，4-二氟、3，4，5-三氟；(2) The aromatic boronic acid referred to is a derivative of phenylboronic acid substituted by R group; R is hydrogen, ortho- or para-position 1-12 carbon straight-chain alkyl, alkoxy, carbonyl, 4-n-propyl - cyclohexyl, 4-fluoro, 3,4-difluoro, 3,4,5-trifluoro;

(3)所指的联苯型TFT-LCD用液晶化合物，是由上述反应物经交叉偶联反应生成联苯型TFT-LCD用液晶化合物。The liquid crystal compound for biphenyl type TFT-LCD referred to in (3) is a liquid crystal compound for biphenyl type TFT-LCD produced by cross-coupling reaction of the above-mentioned reactants.

2.根据权利要求1所述的二苯基膦乙酸钯催化交叉偶联合成液晶化合物的方法，其特征是：主催化剂是二苯基膦乙酸钯型配合物，2. the method for the palladium diphenylphosphine acetate catalyzed cross-coupling synthesis liquid crystal compound according to claim 1 is characterized in that: the main catalyst is a palladium diphenylphosphine acetate complex,

(1)所指的二苯基膦乙酸钯型催化剂的配体是：Ph₂P(CH₂)_nCO₂H，n＝1-3；(1) The ligand of the diphenylphosphine palladium acetate catalyst is: Ph₂ P(CH₂ )_n CO₂ H, n=1-3;

(2)该配合物是由1摩尔的NaPdCl₄与2摩尔的二苯基膦乙酸钠型配体在室温、水相中反应得到的黄色固体，具有cis-Pd(Ph₂PCH₂COO)₂结构；(2) The complex is a yellow solid obtained by reacting 1 mole of NaPdCl₄ with 2 moles of diphenylphosphine acetate sodium ligand at room temperature in water phase, with cis-Pd(Ph₂ PCH₂ COO)₂ structure;

(3)该催化剂在碱性条件下使用，所指的碱是磷酸钾或碳酸钾，它是助催化剂。(3) The catalyst is used under alkaline conditions, and the alkali referred to is potassium phosphate or potassium carbonate, which is a promoter.