Isobutene hydroformylation catalytic system and method for catalytically synthesizing isovaleraldehyde

Abstract

The invention discloses an isobutene hydroformylation catalytic system and a method for catalytically synthesizing isovaleraldehyde. The invention provides a preparation method of isovaleraldehyde, which comprises the following step: in a solvent, in the presence of a rhodium catalyst, a phosphite ester ligand and a phosphoramidite ligand, isobutene reacts with hydrogen and carbon monoxide to generate isovaleraldehyde. The isovaleraldehyde generated by the method is good in selectivity, high in conversion rate, good in stability of a catalytic system, easy to separate from a product and easy to subsequently recycle and reuse.

Description

Technical Field

[0001] The invention relates to an isobutylene hydroformylation catalytic system and a method for catalytically synthesizing isovaleraldehyde. Background Art

[0002] In the field of chemistry, isobutylene hydroformylation is an important organic synthesis pathway and is of great significance for the preparation of high value-added aldehyde compounds. In this reaction, the selection of catalysts and ligands and the stability of the catalyst system will become the key factors determining the reaction efficiency, selectivity and cost.

[0003] Ligands play multiple roles in the isobutylene hydroformylation reaction. First, they can affect the electronic structure and spatial environment of the catalyst center metal, thereby regulating its activation ability and selectivity for reactants. For example, certain ligands with strong electron-donating ability can increase the electron density of the metal center, promote hydrogen activation and isobutylene coordination, and thus increase the reaction rate.

[0004] Different types of ligands show different performances in the isobutylene hydroformylation reaction. Phosphine ligands are one of the most widely studied types. The substituent structure and electronic properties of phosphine ligands have a significant effect on the selectivity and activity of the reaction. Phosphine ligands with large steric hindrance can effectively inhibit the occurrence of side reactions and improve the selectivity of linear aldehyde products; while phosphine ligands with specific electronic effects help to enhance the activity of the catalyst.

[0005] Patent CN1235853C uses water-soluble triphenylphosphine ligand modified rhodium as a catalyst to catalyze the hydroformylation reaction of isobutylene to prepare isovaleraldehyde; however, the reaction temperature and pressure are both high, and the ligand is easily decomposed, so the number of applications is limited.

[0006] Patent CN106008184B uses acetylacetonato triphenylphosphine carbonyl rhodium as a catalyst, triphenylphosphine as a ligand, and n-decane as a solvent to carry out a hydroformylation reaction to prepare isovaleraldehyde, but the conversion rate is only 40-50%.

[0007] Patent CN106431869B uses aldehyde as solvent, rhodium compound, phosphorus compound containing o-methylphenyl group, hard base pentavalent phosphorus oxide, bidentate phosphite composition to catalyze isobutylene hydroformylation to synthesize isovaleraldehyde; however, its conversion rate is low, selectivity is average, and ligand synthesis is complex.

[0008] Patent CN111085198B uses a carrier loaded with three metal active components as a catalyst to catalyze the hydroformylation reaction of isobutylene to prepare isovaleraldehyde; the required catalysts are of various types and the loaded synthesis is complicated. The conversion rate is acceptable, but the selectivity is only 94%, which is not very high.

[0009] Patent CN112010906B uses a homemade special diphosphite combined with a transition metal for olefin hydroformylation, olefin isomerization hydroformylation, olefin alkoxycarbonylation, olefin hydrocarboxylation or olefin hydrocyanation. However, its product selectivity and conversion rate are low, and the catalyst has not been applied. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a new catalytic system for efficiently catalyzing the hydroformylation reaction of isobutylene to generate isovaleraldehyde in view of the defects of the prior art. The present invention provides an isobutylene hydroformylation catalytic system and a method for catalytically synthesizing isovaleraldehyde. The isovaleraldehyde generated by the method has good selectivity and high conversion rate, and the catalytic system has good stability, is easy to separate from the product, and is easy to be recovered and applied later.

[0011] The present invention solves the above technical problems through the following technical solutions.

[0012] The invention provides a method for preparing isovaleraldehyde, which comprises the following steps: in a solvent, in the presence of a rhodium catalyst, a phosphite ligand and a phosphinamide ligand, isobutylene is subjected to a hydroformylation reaction with hydrogen and carbon monoxide to generate isovaleraldehyde; the phosphinamide ligand is

[0013] in,

[0014] R1 and R2 are independently C1-C8 alkyl, C2-C8 alkenyl, a Substituted C1-C8 alkyl or one or more R b Substituted C2-C8 alkenyl; or,

[0015] R1, R2 together with the adjacent O atoms and P atoms form a 5-12 membered heteroaryl group;

[0016] R a and R b are independently cyano or C6-C 10 Aryl;

[0017] R3 and R4 are independently C1-C8 alkyl.

[0018] In certain preferred embodiments of the present invention, certain groups of the phosphoramidite ligand are defined as follows, and the unmentioned groups are the same as those described in any embodiment of the present invention (referred to as "in some embodiments of the present invention").

[0019] In some embodiments of the present invention, R1 is C1-C8 alkyl, C2-C8 alkenyl, a Substituted C1-C8 alkyl.

[0020] In some embodiments of the present invention, R2 is C1-C8 alkyl, C2-C8 alkenyl, a Substituted C1-C8 alkyl.

[0021] In some embodiments of the present invention, each of the C1-C8 alkyl groups is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl; preferably methyl, ethyl, isopropyl or tert-butyl.

[0022] In some embodiments of the present invention, each of the C2-C8 alkenyl groups is independently a C2-C6 straight or branched alkenyl group; for example, vinyl, Preferably

[0023] In some embodiments of the present invention, the C6-C 10 Aryl is independently phenyl or naphthyl.

[0024] In some embodiments of the present invention, the 5-12 membered heteroaryl is

[0025] In some embodiments of the present invention, R1 and R2 are the same.

[0026] In some embodiments of the present invention, R3 and R4 are the same.

[0027] In some embodiments of the present invention, R1 and R2 are independently tert-butyl, benzyl or propenyl.

[0028] In some embodiments of the present invention, R3 and R4 are independently isopropyl or ethyl.

[0029] In some embodiments of the present invention, the phosphoramidite ligand may be one or more of N,N-diisopropylphosphoramidite di-tert-butyl ester, N,N-diisopropylphosphoramidite dibenzyl ester, N,N-diisopropylphosphoramidite diallyl ester, bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite, diethyl-N,N-diisopropylphosphoramidite and o-xylylene-N,N-diethylphosphoramidite; preferably bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite.

[0030] In some embodiments of the present invention, the phosphite ligand may be a monodentate or multidentate phosphite ligand;

[0031] Preferably, the phosphite ligand is one or more of triisooctyl phosphite, triphenyl phosphite, tri(2-ethylhexyl) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphine heteroheptyl oxadiphenyl) (Biphephos); preferably tri(2,4-di-tert-butylphenyl) phosphite, triphenyl phosphite or bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0032] In some embodiments of the present invention, the rhodium catalyst may be one or more of dicarbonyl acetylacetonate rhodium, triphenylphosphine acetylacetonate rhodium and tris(triphenylphosphine)carbonyl rhodium hydride; preferably dicarbonyl acetylacetonate rhodium.

[0033] In some embodiments of the present invention, the solvent may be one or more of toluene, xylene, chlorobenzene, cyclohexane, isovaleraldehyde, n-heptane, dioxane, N-methylpyrrolidone, diisobutyl phthalate and diisobutyl phthalate; preferably xylene, cyclohexane or isovaleraldehyde.

[0034] In some embodiments of the present invention, the molar ratio of the isobutylene to the rhodium catalyst may be 1:(0.02-1.04)*10 -3 ; preferably 1:0.31*10 -3 .

[0035] In some embodiments of the present invention, the molar ratio of the isobutylene to the phosphite ligand may be 1:(0.005-0.05); preferably 1:0.015, 1:0.012, 1:0.008 or 1:0.013.

[0036] In some embodiments of the present invention, the molar ratio of the isobutylene to the phosphinamide ligand may be 1:(0.001-0.01); preferably 1:0.003, 1:0.004, 1:0.002, 1:0.008 or 1:0.009.

[0037] In some embodiments of the present invention, the molar mass ratio of the isobutylene to the solvent may be 0.005 to 0.05 mol / g, preferably 0.009 mol / g.

[0038] In some embodiments of the present invention, the volume ratio of the hydrogen to the carbon monoxide is 1:(0.5-2); preferably 1:1 or 1:1.2.

[0039] In some embodiments of the present invention, the amount of the hydrogen and the carbon monoxide used can be the conventional amount for such reactions in the art. Preferably, the pressure at which the hydrogen and the carbon monoxide are introduced into the system is 0.5 to 2.5 MPa; preferably 2 MPa or 2.5 MPa.

[0040] In some embodiments of the present invention, the reaction temperature is preferably 80-120°C; preferably 90-95°C.

[0041] In some embodiments of the present invention, the feed materials for the reaction consist of a solvent, a rhodium catalyst, a phosphite ligand, a phosphinamide ligand, isobutylene, CO and H2.

[0042] In some embodiments of the present invention, the reaction includes the following reaction steps: dissolving the rhodium catalyst, the phosphite ligand and the phosphinamide ligand in the solvent, replacing with an inert gas (such as nitrogen), adding isobutylene and a mixed gas of CO and H2 to 0.5-2.5MPa, and maintaining 80-120°C to react to obtain isovaleraldehyde.

[0043] In some embodiments of the present invention, the reaction further comprises the following post-treatment step: after the reaction is completed, the reaction system is subjected to reduced pressure distillation, and the remaining catalyst system can re-participate in the reaction; the catalyst system comprises the rhodium catalyst, the phosphite ligand and the phosphinamide ligand.

[0044] The present invention also provides a catalytic system, which comprises the rhodium catalyst described in any scheme of the present invention, the phosphite ligand described in any scheme of the present invention, and the phosphinamide ligand described in any scheme of the present invention.

[0045] In some embodiments of the present invention, the catalytic system is composed of the rhodium catalyst described in any embodiment of the present invention, the phosphite ligand described in any embodiment of the present invention, and the phosphinamide ligand described in any embodiment of the present invention.

[0046] The present invention also provides an application of the catalytic system described in any scheme of the present invention in a hydroformylation reaction.

[0047] In some embodiments of the present invention, the reaction conditions of the hydroformylation reaction are as described in any embodiment of the present invention.

[0048] The term "one or more" means 1, 2 or 3.

[0049] The term "alkyl" refers to a linear or branched, saturated, monovalent hydrocarbon group having a specified number of carbon atoms (e.g., C1-C8, etc.). Alkyl includes, but is not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, etc.

[0050] The term "alkenyl" refers to a linear or branched, unsaturated, monovalent hydrocarbon radical having a specified number of carbon atoms (e.g., C2-C8) and having one or more (e.g., 1, 2, or 3) carbon-carbon sp 2 Double bond. Alkenyl groups include but are not limited to: vinyl, wait.

[0051] The term "aryl" refers to a group having a specified number of carbon atoms (e.g., C6-C 10 ) is a cyclic, unsaturated, monovalent hydrocarbon group, which is a single ring or multiple rings (e.g., 2 or 3). When it is a multiple ring, two atoms and a bond are shared between adjacent single rings, and each ring is aromatic. Aryl includes, but is not limited to, phenyl, naphthyl, etc.

[0052] The term "heteroaryl" refers to a cyclic, unsaturated, monovalent group having a specified number of ring atoms (e.g., 5-12 members), a specified number of heteroatoms (e.g., 1, 2, 3, or 4), a specified type of heteroatom (one or more of N, O, S, and P), which is monocyclic or polycyclic, and in the case of polycyclic, two atoms and one bond are shared between adjacent monocyclic rings, and at least one ring is aromatic. A heteroaryl group is attached to the rest of the molecule through a carbon atom or a heteroatom; a heteroaryl group is attached to the rest of the molecule through a ring with heteroatoms or a ring without heteroatoms; a heteroaryl group is attached to the rest of the molecule through a ring with aromatic properties or a ring without aromatic properties. Heteroaryl groups include, but are not limited to: wait.

[0053] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0054] The reagents and raw materials used in the present invention are commercially available.

[0055] The positive and progressive effects of the present invention are:

[0056] (1) The isovaleraldehyde generated by the catalytic system of the present invention has good selectivity and high conversion rate;

[0057] (2) The catalytic system of the present invention has good stability, is easy to separate from the product, and is easy to recover and reuse later. DETAILED DESCRIPTION

[0058] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0059] The present invention will be described in detail below through examples.

[0060] The raw materials, solvents, catalysts, etc. used in the following examples were all purchased from commercial sources; the product purity was determined by gas chromatography (GC); and the molar yield was calculated by actual yield / theoretical yield×100%.

[0061] Gas chromatography (GC) analysis conditions: chromatographic column DB-1*30m*0.32mm*1.0μm; injection port 300℃; split ratio 10:1; flow rate 2.0ml / min, DET*10-2; detector 300℃; column temperature 40℃ / 2min, 20℃ / min, 260℃ / 15min.

[0062] Example 1

[0063] Rhodium dicarbonyl acetylacetonate (150 mg) and mixed ligand (16 g) (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite) were dissolved in (200 g) of xylene and added to a 1 L autoclave. After being fully replaced with an inert gas (nitrogen), 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction temperature was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 377.2 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 99%, and the yield was 99%. After the obtained material is subjected to vacuum distillation to separate the product, the remaining catalytic system containing the catalyst (rhodium catalyst, phosphite ligand and phosphinamide ligand) and high-boiling liquid can be continuously recycled.

[0064] Characterization of Isovaleraldehyde:

[0065] The peak retention time of gas chromatography (GC) was 3.3min;

[0066] The gas phase retention time is consistent with that of the standard sample, and the purity (more than 98%) meets the requirements for subsequent reactions.

[0067] Example 2

[0068] Dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of N,N-diisopropylphosphoramidite diallyl ester) were dissolved in (200 g) of xylene and added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 375 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 99%, the yield was 98%, and the purity was above 98%.

[0069] Example 3

[0070] Dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of o-xylylene-N,N-diethylphosphoramidite) were dissolved in (200 g) xylene and added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 373.7 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 99%, the yield was 97%, and the purity was above 98%.

[0071] Example 4

[0072] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of N,N-diisopropylphosphoramidite dibenzyl ester) in (200 g) xylene, add to 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2 MPa, keep the reaction at 90-95°C, continue to inject the mixed gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 373.3 g of material. The material is subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde is 99%, the yield is 96.7%, and the purity is above 98%.

[0073] Example 5

[0074] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of di-tert-butyl N,N-diisopropylphosphoramidite) in (200 g) xylene, add to 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2 MPa, keep the reaction at 90-95°C, continue to inject the mixed gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 372 g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 99%, the yield is 96%, and the purity is above 98%.

[0075] Example 6

[0076] Dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of triphenyl phosphite and 1.6 g of bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite) were dissolved in (200 g) of xylene, and then added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa, the temperature was raised to 90°C, and the mixed gas was supplemented to 2.5 MPa, and the reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 375.3 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 97%, the yield was 96%, and the purity was above 98%.

[0077] Example 7

[0078] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g triphenyl phosphite and 1.6 g N, N-diisopropylphosphoramidite diallyl ester) in (200 g) xylene, add to 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2.5 MPa, keep 90-95°C to start the reaction, continue to inject the mixed gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 374.4 g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 98%, the yield is 96.4%, and the purity is above 98%.

[0079] Example 8

[0080] Dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 12 g of tris(2,4-di-tert-butylphenyl)phosphite and 4 g of bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite) were dissolved in (200 g) of xylene and added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1.2 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 374.2 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 97%, the yield was 95.3%, and the purity was above 98%.

[0081] Example 9

[0082] Dicarbonyl acetylacetonate rhodium (150mg) and mixed ligand (16g), (including 12g triphenyl phosphite and 4g N,N-diisopropylphosphoramidite diallyl ester) were dissolved in (200g) xylene, and then added to a 1L autoclave. After being fully replaced by inert gas, 105g (1.87mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1.2 was introduced to 0.5MPa, the temperature was raised to 90°C, and the mixed gas was supplemented to 2MPa, and the reaction was maintained at 90-95°C, and the mixed gas was continuously charged, and the reaction was carried out for 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 351g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 98%, the yield was 96%, and the purity was above 98%.

[0083] Example 10

[0084] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 8 g of tris (2,4-di-tert-butylphenyl) phosphite and 8 g of diethyl-N,N-diisopropylphosphoramidite) in (200 g) xylene, add to 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2 MPa, keep 90-95°C to start the reaction, continue to charge with synthesis gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 375 g of material. The material is subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde is 96%, the yield is 94.8%, and the purity is above 98%.

[0085] Embodiment 11

[0086] Rhodium dicarbonyl acetylacetonate (150 mg) and mixed ligands (16 g), (including 14.4 g of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite and 1.6 g of bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite) were dissolved in (200 g) of isovaleraldehyde and added into a 1 L autoclave. After being fully replaced with an inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction time of 6 hours. The reaction system was cooled to room temperature, and 374.7 g of material was extracted. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, it was obtained that the selectivity of isovaleraldehyde was 97%, the yield was 95.6%, and the purity was above 98%.

[0087] Example 12

[0088] Rhodium dicarbonyl acetylacetonate (150 mg) and mixed ligand (16 g), (bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite 14.4 g, N,N-diisopropylphosphoramidite di-tert-butyl ester 1.6 g) were dissolved in (200 g) cyclohexane and added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa. The temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa. The reaction was maintained at 90-95°C, and the mixed gas was continuously introduced for a total reaction of 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 370.4 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 97%, the yield was 93%, and the purity was above 98%.

[0089] The reaction system of the above embodiment is cooled to room temperature, and after sampling and testing, the obtained material is subjected to vacuum distillation to separate the product, and the remaining catalyst system containing the catalyst (rhodium catalyst, phosphite ligand and phosphinamide ligand) and high boiling liquid is recycled back to the new reaction system for application. The number of applications and the results are shown in Table 1:

[0090] Table 1

[0091]

[0092] Note: When the conversion rate is lower than 92%, the application is terminated. The number of applications is the number of times the catalyst solution is repeated at this time.

[0093] From the results, it can be obtained that the average yield of the mixed ligand (tris(2,4-di-tert-butylphenyl)phosphite 14.4g, bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite 1.6g) is as high as 95% and above, and the number of applications is as high as 51 times.

[0094] Comparative Example 1

[0095] Dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of tris(2,4-di-tert-butylphenyl)phosphite and 1.6 g of triphenylphosphine) were dissolved in (200 g) of xylene, and then added to a 1 L autoclave. After being fully replaced by inert gas, 105 g (1.87 mol) of isobutylene was then injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5 MPa, the temperature was raised to 90°C, and the mixed gas was supplemented to 2 MPa, and the reaction was maintained at 90-95°C, and the mixed gas was continuously introduced, and the reaction was carried out for 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 360 g of material. The material was subjected to gas phase purity analysis and gas phase content detection. Finally, the selectivity of isovaleraldehyde was 85% (i.e., the molar ratio of the generated isovaleraldehyde to pivalaldehyde (by-product) was 5.67), and the yield was 76%.

[0096] Comparative Example 2

[0097] Dissolve dicarbonyl acetylacetonate rhodium (150mg) and mixed ligand (16g), (including 12g triphenyl phosphite and 4g diphenyl cyclohexyl phosphite) in (200g) xylene, add to 1L autoclave, fully replace with inert gas, then pressurize and inject 105g (1.87mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5MPa, heat to 90°C, add the mixed gas to 2MPa, keep the reaction at 90-95°C, continue to inject the mixed gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 352.8g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 80%, and the yield is 68%.

[0098] Comparative Example 3

[0099] Tris(triphenylphosphine)carbonyl hydride rhodium (136mg) and mixed ligand (16g), (including 14.4g triphenylphosphine and 1.6g diethyl-N,N-diisopropylphosphoramidite) were dissolved in (200g) xylene, and then added to a 1L autoclave. After being fully replaced by inert gas, 105g (1.87mol) of isobutylene was injected under pressure, and a mixed gas of CO and H2 with a volume ratio of 1:1 was introduced to 0.5MPa, the temperature was raised to 90°C, and the mixed gas was supplemented to 2MPa, and the reaction was maintained at 90-95°C, and the mixed gas was continuously charged, and the reaction was carried out for 6 hours. The reaction system was cooled to room temperature, and the material was extracted to obtain 365.9g of material. The material was subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde was 77%, and the yield was 71.7%.

[0100] Comparative Example 4

[0101] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and mixed ligand (16 g), (including 14.4 g of 1,4-bis(diphenylphosphino)butane (dppb) and 1.6 g of tri(2-ethylhexyl) phosphite) in (200 g) xylene, add to 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2 MPa, keep the reaction at 90-95°C, continue to charge with synthesis gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 361.6 g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 73% and the yield is 66%.

[0102] Comparative Example 5

[0103] Dissolve dicarbonyl acetylacetonate rhodium (150mg) and a single ligand (16g of triisooctyl phosphite) in (200g) xylene, add to a 1L autoclave, fully replace with inert gas, then pressurize and inject 105g (1.87mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5MPa, heat to 90°C, add the mixed gas to 2MPa, keep the reaction at 90-95°C, continue to charge with synthesis gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 340.5g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 75%, and the yield is 58%.

[0104] Comparative Example 6

[0105] Dissolve dicarbonyl acetylacetonate rhodium (150 mg) and a single ligand (triphenylphosphine oxide 16 g) in (200 g) xylene, add to a 1 L autoclave, fully replace with inert gas, then pressurize and inject 105 g (1.87 mol) of isobutylene, introduce a mixed gas of CO and H2 with a volume ratio of 1:1 to 0.5 MPa, heat to 90°C, add the mixed gas to 2 MPa, maintain the reaction at 90-95°C, continue to charge with synthesis gas, and react for 6 hours. The reaction system is cooled to room temperature, and the material is extracted to obtain 348.4 g of material. The material is subjected to gas phase purity analysis and gas phase content detection, and finally, the selectivity of isovaleraldehyde is 62%, and the yield is 51%.

[0106] After the product was removed from the reaction system of the above comparative example by vacuum distillation, the catalyst system was further recycled and reused. The number of times of recycling and the results are shown in Table 2:

[0107] Table 2

[0108]

[0109] Note: When the conversion rate is lower than 92%, the application is terminated. The number of applications is the number of times the catalyst solution is repeated at this time.

[0110] From the results, it can be seen that the yield and application times of the mixed ligand or single ligand in the comparative example are both lower than those in the above embodiment.

Claims

1. A method for preparing isovaleraldehyde, characterized in that, The method comprises the following steps: in a solvent, in the presence of a rhodium catalyst, a phosphite ligand and a phosphinamide ligand, isobutylene is subjected to a hydroformylation reaction with hydrogen and carbon monoxide to generate isovaleraldehyde; The phosphinamide ligand is in, R1 and R2 are independently C1-C8 alkyl, C2-C8 alkenyl, a Substituted C1-C8 alkyl or one or more R b Substituted C2-C8 alkenyl; or, R1, R2 together with the adjacent O atoms and P atoms form a 5-12 membered heteroaryl group; R a and R b are independently cyano or C6-C 10 Aryl; R3 and R4 are independently C1-C8 alkyl.

2. The preparation method according to claim 1, characterized in that In the phosphinamide ligand, R1 is C1-C8 alkyl, C2-C8 alkenyl, or one or more R a Substituted C1-C8 alkyl; and / or, R2 is C1-C8 alkyl, C2-C8 alkenyl, a Substituted C1-C8 alkyl.

3. The preparation method according to claim 1, characterized in that: The phosphinamide ligand satisfies one or more of the following conditions: (1) Each of the C1-C8 alkyl groups is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl; preferably methyl, ethyl, isopropyl or tert-butyl; (2) Each of the C2-C8 alkenyl groups is independently a C2-C6 straight-chain or branched alkenyl group; for example, vinyl, Preferably (3) C6-C 10 Aryl is independently phenyl or naphthyl; (4) The 5-12 membered heteroaryl group is 4. The preparation method according to claim 1, characterized in that: It meets one or more of the following conditions: (1) R1 and R2 are the same; (2) R3 and R4 are the same; (3) R1 and R2 are independently tert-butyl, benzyl or propenyl; (4) R3 and R4 are independently isopropyl or ethyl; (5) The phosphite ligand is a monodentate or multidentate phosphite ligand.

5. The preparation method according to claim 1, characterized in that: It meets one or more of the following conditions: (1) The phosphinamide ligand is one or more of N,N-diisopropylphosphinamide di-tert-butyl ester, N,N-diisopropylphosphinamide dibenzyl ester, N,N-diisopropylphosphinamide diallyl ester, bis(2-cyanoethyl)-N,N-diisopropylphosphinamide, diethyl-N,N-diisopropylphosphinamide and o-xylylene-N,N-diethylphosphinamide; (2) The phosphite ligand is one or more of triisooctyl phosphite, triphenyl phosphite, tri(2-ethylhexyl) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and 6,6'-[(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[D,F][1,3,2]dioxaphosphinyl)heptaerythritol; (3) The rhodium catalyst is one or more of dicarbonyl acetylacetonate rhodium, triphenylphosphine acetylacetonate rhodium and tris(triphenylphosphine)carbonyl rhodium hydride; (4) The solvent is one or more of toluene, xylene, chlorobenzene, cyclohexane, isovaleraldehyde, n-heptane, dioxane, N-methylpyrrolidone, diisobutyl phthalate and diisobutyl phthalate; (5) The molar ratio of the isobutylene to the rhodium catalyst is 1:(0.02-1.04)*10 -3 ; (6) The molar ratio of the isobutylene to the phosphite ligand is 1:(0.005-0.05); (7) The molar ratio of the isobutylene to the phosphinamide ligand is 1:(0.001-0.01); (8) The concentration of isobutylene in the solvent is 0.005 to 0.05 mol / g; (9) The volume ratio of the hydrogen to the carbon monoxide is 1:(0.5-2); (10) The reaction temperature is 80 to 120° C.; (11) introducing the hydrogen and the carbon monoxide into the system at a pressure of 0.5 to 2.5 MPa; (12) The reaction comprises the following steps: dissolving the rhodium catalyst, the phosphite ligand and the phosphinamide ligand in the solvent, replacing with an inert gas, adding isobutylene and a mixed gas of CO and H2 to 0.5-2.5 MPa, and maintaining the temperature at 80-120° C. to obtain isovaleraldehyde; (13) The reaction further comprises the following post-treatment step: after the reaction is completed, the reaction system is subjected to reduced pressure distillation, and the remaining catalyst system can re-participate in the reaction; the catalyst system comprises the rhodium catalyst, the phosphite ligand and the phosphinamide ligand.

6. The preparation method according to claim 5, characterized in that: It meets one or more of the following conditions: (1) The phosphoramidite ligand is bis(2-cyanoethyl)-N,N-diisopropylphosphoramidite; (2) The phosphite ligand is tris(2,4-di-tert-butylphenyl)phosphite, triphenyl phosphite or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; (3) The rhodium catalyst is dicarbonyl acetylacetonate rhodium; (4) The solvent is xylene, cyclohexane or isovaleraldehyde; (5) The molar ratio of the isobutylene to the rhodium catalyst is 1:0.31*10 -3 ; (6) the molar ratio of the isobutylene to the phosphite ligand is 1:0.015, 1:0.012, 1:0.008 or 1:0.013; (7) The molar ratio of the isobutylene to the phosphinamide ligand is 1:0.003, 1:0.004, 1:0.002, 1:0.008 or 1:0.009; (8) The concentration of isobutylene in the solvent is 0.009 mol / g; (9) The volume ratio of the hydrogen to the carbon monoxide is 1:1 or 1:1.2; (10) The reaction temperature is 90-95°C; (11) The pressure of the hydrogen and the carbon monoxide introduced into the system is 2 MPa or 2.5 MPa.

7. The preparation method according to claim 1, characterized in that: The feed materials for the reaction are composed of solvent, rhodium catalyst, phosphite ligand, phosphinamide ligand, isobutylene, CO and H2.

8. A catalytic system, characterized in that: It comprises the rhodium catalyst according to any one of claims 1 to 7, the phosphite ligand according to any one of claims 1 to 7, and the phosphinamide ligand according to any one of claims 1 to 7; Preferably, the catalytic system consists of the rhodium catalyst as claimed in any one of claims 1 to 7, the phosphite ligand as claimed in any one of claims 1 to 7 and the phosphinamide ligand as claimed in any one of claims 1 to 7.

9. Use of the catalytic system according to claim 8 in a hydroformylation reaction.

10. The use according to claim 9, characterized in that The reaction conditions of the hydroformylation reaction are as described in any one of claims 1 to 7.

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