CN1060412C - Phosphine ligand with temp. controlled phase transfer function, and application thereof - Google Patents

Abstract

The present invention provides (A), the nonionic surface active water-soluble phosphine ligand with temperature control phase transfer function of (B) two types of structures:

Wherein the end group R=C ₅ ~C ₁₈ alkyl or phenyl, m=1~2, n=10~30;

The complexes of the above-mentioned phosphine ligands characterized by cloud point and rhodium Rh show good catalytic performance for the water/organic two-phase hydroformylation of higher olefins. The catalyst can be separated by simple phase separation and is suitable for Synthesis of isomeric aldehydes as the main target product.

Description

Phosphine ligands with temperature-controlled phase transfer function and their applications

The invention belongs to a homogeneous complex catalyst and its application in water/organic two-phase high carbon olefin hydroformylation.

A major problem in the industrial application of homogeneous complex catalysis is the separation and recycling of transition metal catalysts. The emergence of the water/organic two-phase catalytic system using the complexes of water-soluble phosphine ligands and rhodium as catalysts provides an effective way to solve the separation of catalysts. The first industrial application was the water-soluble triphenylphosphine (TPPTS) and rhodium (Rh) complex [HRh(CO)(TPPTS) ₃ ] catalyzed propylene water/organic two-phase hydrogen formaldehyde Acylation of n-butyraldehyde [DE-2627354]. However, when the TPPTS/Rh catalyst is used for the water/organic two-phase hydroformylation of high-carbon olefins, it is difficult to carry out the reaction because the water solubility of high-carbon olefins is too small, and the reaction conversion rate of 1-hexene is only about 20%. The patent [DE-3412335 (1985) of Ruhr Chemical Company, DE-3420491 (1985), CN-85105102 (1986)] proposes to add the method for quaternary ammonium salt phase-transfer agent, improves water/organic two-phase high carbon olefin hydrogen Effects of formylation reactions. However, the presence of a phase transfer agent adds to the problem of separation of the product from the phase transfer agent. The present inventor Jin Zilin et al. found that the complex of the water-soluble phosphine ligand tris-p-hydroxypolyoxyethylene phenylphosphine with ethoxy group and Rh can make the water of C ₆ -C ₁₂ olefins in the absence of a phase transfer agent. /Organic two-phase hydroformylation is well carried out [<Molecular Catalysis>9(2), 147, 1994; J. Prakt． Chemie 338, 124 (1996)].

Water-soluble phosphine ligands containing ethoxy groups, the first phosphine ligands of the following formulas (1) and (2) in the literature [Chem. Lett． 977, (1982)]. Nonionic water-soluble phosphine complexes can be synthesized by reacting polyethylene glycol (PEG) with dichlorophenylphosphine (PhPCl ₂ ) and brominated polyethylene glycol (PEG-Br) with lithium diphenylphosphine (LiPPh ₂ ). Body (3) and (4) [J. Poly． Sci． Chem． Ed;22(2)350(1984)]

The above-mentioned phosphine ligands (1-4), lack of enough lipophilic groups, do not show the characteristics of non-ionic surfactants - cloud point.

According to the theory of nonionic surfactants, the water solubility generated by the ethoxy chain is due to the hydrogen bond formed between it and water molecules, so this water solubility has the characteristic of decreasing with the increase of temperature. For the first time, Jin Zilin et al. synthesized a water-soluble phosphine ligand with a cloud point, and proposed that the good catalytic activity of its complex with rhodium in the water/organic two-phase hydroformylation of higher carbon olefins should be attributed to the formation of the cloud point. The temperature-controlled phase transfer function: this kind of phosphine ligand that is soluble in water at room temperature will lose its water solubility and precipitate from the water phase and dissolve into the organic phase when the reaction temperature exceeds the cloud point, so that the reaction proceeds in the organic phase ; And when the reaction is cooled below the cloud point, the phosphine ligand returns from the oil phase to the water phase [J. Mol． Cat． A． Chemical, 116, 55 (1997)].

The present invention proposes (A) and (B) two types of non-ionic surface active water-soluble phosphine ligands with temperature-controlled phase transfer function and their high carbon olefin (C ₆ -C ₁₂ ) water/organic two-phase hydrogen Application in formylation reaction.

Wherein the end group R=C ₅ ~C ₁₈ alkyl or phenyl, m=1~2, n=10~30;

The phosphine ligand (A) is prepared by reacting fatty alcohol polyoxyethylene ether R—(—OCH ₂ CH ₂ —) _n —OH with different n and R with Ph ₂ PCl and PhPCl ₂ respectively. It is characterized in that the terminal group is >C ₅ alkyl or phenyl. The phosphine ligand (B) can be synthesized from R>C ₅ R(OCH ₂ CH ₂ ) _n OH and catechol phosphorous acid chloride (C).

利用膦配体的浊点特征所产生的温控相转移功能，可以制得温控相转移膦／铑催化剂，其在水／有机两相体系中发生的温控相转移催化作用过程描述如下：When the ethoxy chain length n in the structures (A) and (B) is greater than or equal to 10, the phosphine ligand has good water solubility. But only when the carbon number of R is greater than 5; and the ratio of lipophilic group Cj (total carbon number of phenyl and R group) to hydrophilic group n (ethoxyl chain length) n/Cj≥0.5, the phosphine ligand Only then does it present the cloud point and produce a temperature-controlled phase transfer function. The size of the cloud point can be tuned by changing n and R. The present invention synthesizes phosphine ligands with cloud points in the range of 30-100°C (see the table below).

Using the temperature-controlled phase transfer function produced by the cloud point characteristics of the phosphine ligand, a temperature-controlled phase-transfer phosphine/rhodium catalyst can be prepared. The temperature-controlled phase-transfer catalysis process that occurs in the water/organic two-phase system is described as follows:

In the water/organic two-phase reaction system (see the accompanying drawings), the water-soluble (A)/Rh or (B)/Rh catalyst C is in the lower aqueous phase at the beginning of the reaction (at room temperature), and the substrate S In the upper organic phase, the reaction system is heated, and when the temperature rises to a reaction temperature above the cloud point Cp of the phosphine ligand, catalyst C loses water solubility and precipitates from the water phase and transfers to the organic phase. Therefore, at a reaction temperature higher than the cloud point, the catalyst C and the substrate S are in the same organic phase, and the reaction is carried out in the organic phase instead of the water phase, so the reaction is not affected by the low water solubility of the substrate S. After the reaction is completed and cooled to a temperature below the cloud point, the catalyst regains its water solubility and returns to the water phase from the organic phase, thereby separating into two phases with the reaction product P remaining in the oil phase, so that catalyst C can be separated by simple phase separation separate from the product.

The Rh complexes of phosphine ligands (A) and (B) have good catalytic activity for the hydroformylation reaction of water/organic two-phase higher carbon olefins (C ₆ —C ₁₂ ). The reaction pressure of syngas CO/H ₂ (volume ratio=1:1) is 3.0~8.0MPa, phosphine/rhodium (P/Rh)=10~25 (molar ratio), alkene/rhodium=350~1000 (molar ratio), the reaction time is 3 to 10 hours, and the highest conversion rate and aldehyde yield of the reaction reach 98% and 96% respectively.

The water/organic two-phase catalytic system using the Rh complex of the phosphine ligand (A) (B) as the catalyst can form two phases with a clear interface after the reaction is cooled, and the aqueous phase containing the catalyst can be separated by simple phase separation. Can be recycled directly. The organic phase can be non-polar aromatic hydrocarbons such as benzene and toluene, or aliphatic hydrocarbons such as cyclohexane and heptane; it is better to use straight-chain alkanes. The catalytic activity of the catalyst in the water phase remains unchanged after repeated use.

The hydroformylation of water/organic two-phase higher carbon olefins catalyzed by the Rh complex of the phosphine ligand (A) (B) has a low positive/isotropic ratio between 0.8 and 2.8. The content of isomers is relatively high, so the catalytic system of the present invention is particularly suitable for the synthesis of fine chemicals with isomerized aldehydes as the target product, such as the hydroformylation reaction of 1-decene as raw material for the synthesis of edible flavor oranges Aldehyde [ _C8H17CH ( _CH3 )CHO] _.

Example 1

Synthesis of PhP[—(OCH ₂ CH ₂ —) ₁₃ —OC ₈ H ₁₇ ] ₂ : Dissolve 0.025mol C ₈ H ₁₇ (OCH ₂ CH ₂ —) ₁₃ —OH in an appropriate amount of toluene (about 10ml), add to dry In a 100ml three-neck flask, after heating to the reflux temperature, slowly add a toluene (5ml) solution containing 3.6g (0.020mol) PhPCl ₂ dropwise under stirring within 30 minutes, after the dropwise addition, continue to reflux After 3 to 3.5 hours, the toluene was distilled off under reduced pressure. After the crude product was cooled to room temperature, 50ml of ether was added and placed overnight at -15 to -18°C. The product was viscous or waxy. It is easily soluble in water with a cloud point of 59°C.

Example 2

Synthesis of Ph ₂ P—[—(OCH ₂ CH ₂ —) ₁₆ —OC ₈ H ₁₇ ]: Dissolve 0.025mol C ₈ H ₁₇ (OCH ₂ CH ₂ —) ₁₆ —OH in an appropriate amount of toluene (about 10ml) , added to a dry 100ml three-neck flask, after heating to reflux temperature, slowly add a solution of toluene (5ml) containing 5.5g (0.0375mol) Ph ₂ PCl dropwise within 30 minutes under stirring, and the dropwise addition is completed After that, continue to reflux for 3 to 3.5 hours. Toluene was distilled off under reduced pressure. After the crude product was cooled to room temperature, 50ml of diethyl ether was added and left overnight at -15 to -18°C. The product precipitated out in the form of viscous or white wax. It is easily soluble in water with a cloud point of 43°C.

的合成：Example 3

Synthesis:

Put 9.4g (0.068mol) PCl ₃ dropwise into the reaction bottle with 5.0g (0.045mol) catechol under stirring within 15 minutes, react at room temperature for one hour, then dropwise add 3. 9 g of PCl ₃ , heated under reflux on a water bath for two hours, after distilling off excess PCl ₃ , distilled out the reaction product catechol chloride phosphorous acid ester (C).

Put 0.025 mol of C ₈ H ₁₇ —(OC ₂ H ₄ ) ₁₃ —OH and about 10 ml of toluene into a dry 100 ml three-necked flask. Add a toluene solution containing 6.5g (C) (0.0375mol) under stirring at reflux temperature, and continue to reflux for 3 to 3.5 hours after the addition is completed. After the toluene is evaporated, the residue is dissolved in 50ml of ether at room temperature, and the Stand overnight at -15～-18°C, and the product precipitates out as light yellow viscous substance. It is easily soluble in water with a cloud point of 57.5°C.

Example 4

(B)/Rh-catalyzed water/organic two-phase decene hydroformylation: 0.0031 g (1.21×10 ^-5 mol) rhodium acetylacetonate dicarbonyl (Rh(CO) ₂ Acac), 0.0031 g (1.21×10 -5 mol) 14g (1.66×10 ^-4 mol) (B) (P/Rh=13.5), 4.0ml n-heptane, 4.0ml degassed water, 3.0ml (1.6×10 ^-2 mol ) 1-decene and internal standard were added to a 75ml stainless steel autoclave, and the autoclave was flushed with 2.0MPa synthesis gas (H ₂ /CO=1:1) for 5 times after the lid was tightened, and then filled with synthesis gas to the required Reaction pressure, after reacting with a constant temperature oil bath for a predetermined time, take the kettle out of it and cool it to room temperature, and release the pressure. The reaction solution was transferred to a separatory funnel, and the layers were separated. The separated oil phase was dried with anhydrous magnesium sulfate and then sampled for chromatographic analysis. The water phase can be directly reused, and the catalytic activity remains unchanged after three cycles. The reaction temperature is preferably 70-140°C. The reaction pressure (H ₂ /CO=1:1) is preferably 3.0-8.0 MPa, and the pH of the system is 6-7. Under the best reaction conditions, after 4 hours of reaction, the reaction conversion rate and aldehyde yield can reach 98% and 96%, the positive / iso ratio of the product is 0.8, and more than 98% of the isomers are commonly known as orange aldehyde. of 2-methyldecanal.

Example 5

(A)/Rh-catalyzed water/organic biphasic carbadodecene hydroformylation: 0.0031g (1.21×10 ^-5 mol) Rh(CO) ₂ Acac, 0.24g (1.58 ×10 ^-4 mol) (P/Rh=13), 2ml of water, 2ml of toluene and 1.0ml of 1-dodecene (4.5×10 ^-3 ) were added to a 75ml stainless steel autoclave, and the lid was tightened with 2 ．Rinse the autoclave with 0MPa syngas (H ₂ /CO=1:1) five times, then pour syngas to the required reaction pressure, heat in a constant temperature oil bath, and take the autoclave out of the oil bath to cool after the predetermined time. Release the pressure at room temperature. The reaction solution was transferred to a separatory funnel and allowed to stand for stratification. The separated oil phase was dried with anhydrous magnesium sulfate and then sampled for chromatographic analysis. The water phase could be directly reused. The catalytic activity remained unchanged after three cycles. Under the optimal reaction conditions as in Example 5, after 4 hours of reaction, the conversion rate of olefins can reach 97%, the yield of aldehydes is 95%, and the normal/iso ratio of the product is 1.1.

Claims (5)

1. class phosphine/rhodium complex catalyst is characterized in that the hydrophilic group of the phosphine part of this catalyzer is an oxyethyl chain, and its structure is as (A) or (B):

Wherein end group R is C ₅～C ₁₈Alkyl or phenyl, m=1～2, n=10～30; As the total carbon number C of the oleophilic group that constitutes by phenyl and R base _jRatio n/c with the hydrophilic group chain length n that constitutes by oxyethyl chain _j〉=0.5 o'clock, the phosphonic acids body presented cloud point and has the function of temperature control phase transition; They and rhodium dicarbonyl acetylacetonate [Rh (CO) ₂(Acac)] water-soluble (the A)/Rh that cooperate to form or (B)/Rh catalyzer has showed the feature of temperature control phase-transfer catalysis in water/organic two-phase using hydroformylation of higher olefins reaction, and the molar ratio of phosphine/rhodium is 10～25.

2. a class is with the purposes of the described phosphine of claim 1/rhodium complex catalyst; it is characterized in that by phosphorus part (A) or (B) cooperating the catalyzer that forms with rhodium; water-soluble extremely low higher olefins is not being had in the presence of the consisting of phase-transferring agent; also can in water/organic two-phase system, carry out hydroformylation reaction; and after reaction finishes; catalyzer can be by simply being separated and product separates, and the water that contains catalyzer can be recycled, and activity remains unchanged.

3. according to the purposes of the described catalyzer of claim 2, it is characterized in that this catalyzer is 70～100 ℃ in temperature of reaction, synthetic gas (H ₂/ CO=1:1) pressure is 3.0～8.0MPa, pH=6～7, and alkene/rhodium mol ratio is 350～1000, the reaction times is when being 3～10 hours, to C ₆～C ₁₂Higher olefins water/organic two-phase hydroformylation, the peak rate of conversion of alkene reaches 98% and 96% respectively, product just/different ratio is 0.8～2.8.

4. according to the purposes of the described catalyzer of claim 2, the organic phase that it is characterized in that this water/organic two-phase system can be benzene, toluene, ethane or heptane non-polar solvent.

5. according to the purposes of the described catalyzer of claim 2, it is characterized in that with phosphine part (B)/Rh (CO) ₂Acac is 1-decene water/organic two-phase hydroformylation reaction of catalyzer; with the normal heptane is organic phase; be lower than 100 ℃ in temperature; pressure is less than 5.0MPa; under the reaction conditions of pH=6～7, olefin conversion and hydroformylation rate all can be up to 98%, and the content of isomery aldehyde 2-methyl capraldehyde accounts for more than 50%; catalyzer promptly can be recycled through simply being separated, and is the effective ways of preparation edible fruits type spices orange aldehyde 2-methyl capraldehyde.

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