DE10327435A1 - Catalytic hydroformylation of olefins, e.g. internal, highly branched olefins, to aldehydes and alcohols, using unmodified group 8-10 metal, e.g. rhodium, catalyst, is carried out in presence of cyclic (cyclo)alkylene or arylene carbonate - Google Patents

Abstract

Catalytic hydroformylation of 3-24 carbon (C) olefinically unsaturated compounds, using an unmodified catalyst containing group 8-10 metal(s), is carried out in the presence of not less than 1 wt.%, with respect to the reaction mixture, of a cyclic carbonate ester (I), comprising an optionally substituted (cyclo)alkylene or arylene carbonate. Catalytic hydroformylation of 3-24 carbon (C) olefinically unsaturated compounds, using an unmodified catalyst containing group 8-10 metal(s), is carried out in the presence of not less than 1 wt.%, with respect to the reaction mixture, of a cyclic carbonate ester of formula (I), comprising an optionally substituted (cyclo)alkylene or arylene carbonate. R1, R2, R3, R4 = H or optionally substituted 1-27 C aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic or alicyclic-aromatic hydrocarbyl; n = 0-5; X = divalent, optionally substituted 1-27 C aliphatic, alicyclic, aromatic, aliphatic-alicyclic or aliphatic-aromatic hydrocarbyl.

Description

The present invention relates to a process for the preparation of aldehydes by hydroformylation of olefinically unsaturated Compounds, especially olefins, catalyzed by an unmodified Metal catalyst of a metal of the B. to 10. Group of the periodic table of the elements in the presence of cyclic carbonic acid esters as a solvent carried out becomes.

The reactions between olefin compounds, Carbon monoxide and hydrogen in the presence of a catalyst aldehydes that are one carbon atom thicker than hydroformylation (Oxierung) known. As catalysts in these reactions frequently Transition metal compounds the 8th to 10th group of the Periodic Table of the Elements used especially compounds of rhodium and cobalt. The hydroformylation with rhodium compounds offers compared to catalysis with cobalt compounds usually the advantage of higher Chemo- and regioselectivity and is therefore usually more economically attractive.

The one catalyzed by rhodium Hydroformylation are mostly used complexes that consist of rhodium and compounds of the 15th group of the Periodic Table of the Elements, preferably consist of trivalent phosphorus compounds as ligands. Frequently are used as ligands, for example, compounds from the classes the phosphines, phosphites and phosphonites used. An overview of hydroformylation of Olefins can be found in B. CORNILS, W. A. HERRMANN, "Applied Homogeneous Catalysis with Organometallic Compounds ", Vol. 1 & 2, VCH, Weinheim, New York, 1996.

Terminal olefins are easy to use implement in the presence of phosphine-modified rhodium catalysts. Internal and especially internally highly branched In contrast, olefins require strongly activating ligands, such as. B. Phosphite ligands. In the case of olefins which are difficult to oxidize, there has been also the so-called "bare" or unmodified rhodium as well proven suitable. It is one or more metal species, which results from the absence of a metal salt under hydroformylation conditions of modifying ligands. For the purposes of this registration to be understood as modifying ligand compounds which one or more donor atoms of the 15th group of the Periodic Table of the Elements contain. However, alkoxy-, Carbonyl, hydrido, alkyl, aryl, allyl, acyl or alkene ligands apply, as well as the counterions of the metal salts used for catalyst formation, z. B. halides, such as fluoride, chloride, bromide or Iodide, acetylacetonate, carboxylates, such as acetate, 2-ethylhexanoate, Hexanoate, octanoate or nonanoate.

Modifying ligands in the sense in this application are ligands, the donor atoms from the 15th group of the periodic table of the elements as contained, such as nitrogen, Phosphorus, arsenic or antimony and especially phosphorus. The ligands can one or more teeth in the case of chiral ligands, both the racemate and a Enantiomer or diastereomer can be used. As phosphorus ligands are in particular phosphines, phosphinins, phosphinans, phosphine oxides, To name Phosphie, Phosphonite and Phosphinite.

Examples of phosphines are triphenylphosphine, tris (p-tolyl) phosphine, tris (mtolyl) phosphine, tris (o-tolyl) phosphine, tris (p-methoxyphenyl) phosphine, tris (vegetal phenyl) phosphine, tris (p-chlorophenyl) phosphine, Tris (p-dimethylaminophenyl) phosphine, propyldiphenylphosphine, t-butyldiphenylphosphine, n-butyldiphenylphosphine, tricyclophenylphosphine, dicyclo , Tribenzylphosphine, benzyldiphenylphosphine, tri-n-butylphosphine, tri-i-butylphosphine, tri-t-butylphosphine, bis (2-methoxyphenyl) phenylphosphine, neomenthyldiphenylphosphine, the alkali metal, alkaline earth metal, ammonium or other salts of sulfonated triphenyl (triphenyl m-sulfonylphenyl) phosphine, (m-sulfonylphenyl) diphenylphosphine; 1,2-bis (dicyclohexylphosphino) ethane, bis (dicyclohexylphosphino) methane, 1,2-bis (diethylphosphino) ethane, 1,2-bis (2,5-diethylphospholano) benzene [Et-DUPHOS], 1,2-bis (2,5-diethylphospholano) ethane [Et-BPE], 1,2-bis (dimethylphosphino) ethane, bis (dimethylphosphino) methane, 1,2-bis (2,5-dimethylphospholano) benzene [Me-DUPHOS], 1 , 2-bis (2,5-dimethylphospholano) ethane [Me-BPE], 1,2-bis (diphenylphosphino) benzene, 2,3-bis (diphenylphosphino) bicyclo [2.2.1] hept-5-ene [NORPHOS] , 2,2'-bis (diphenylphosphino) -1,1'-binaphthyl [BINAP], 2,2'-bis (diphenylphosphino) -1,1'-bipenyl [BISBI], 2,3-bis (diphenylphosphino) butane , 1,4-bis (diphenylphosphino) butane, 1,2-bis (diphenylphosphino) ethane, bis (2-diphenylphosphinoethyl) phenylphosphine, 1,1'-bis (diphenylphosphino) ferrocene, bis (diphenylphosphino) methane, 1,2- Bis (diphenylphosphino) propane, 2,2 ^{`</sup> bis (di-p-tolylphosphino) -1,1'-binaphthyl, O-isopropylidene-2,3-dihydroxy-1,4-bis (diphenylphosphino) butane [DIOP], 2- (diphenylphosphino) -2'-methoxy-1,1 <sup>`} -binaphthyl, 1- (2-diphenylphosphine o-l-naphthayl) isoquinoline, 1,1,1-tris (diphenylphosphino) ethane, and / or tris (hydroxypropyl) phosphine.

Examples of phosphinins include a. 2,6-dimethyl-4-phenylphosphinin, 2,6-bis (2,4-dimethylphenyl) -4-phenylphosphinin as well as further ligands described in WO 00/55164. Examples of phosphinanes are u. a. 2,6-bis (2,4-dimethylphenyl) -1-octyl-4-phenylphosphinane, 1-octyl-2,4,6-triphenylphosphinane as well as further ligands described in WO 02/00669.

Examples of phosphites are trimethyl phosphite, triethyl phosphite, tri-n-propyl phosphite, tri-ipropyl phosphite, tri-n-butyl phosphite, tri-i-butyl phosphite, tri-t-butyl phosphite, tris (2-ethylhexyl) phosphite, triphenyl phosphite, tris (2.4-di-t-butylphenyl) phosphite, tris (2-t-butyl- 4-methoxyphenyl) phosphite, tris (2-t-butyl-4-methylphenyl) phosphite, tris (p-cresyl) phosphite. In addition, sterically hindered phosphite ligands, such as those found in EP 155 508 , U.S. 4,668,651, U.S. 4,748,261, U.S. 4,769,498, U.S. 4,774,361, U.S. 4,835,299, U.S. 4,885,401, U.S. 5,059,710, U.S. 5,113,022, U.S. 5,179,055, U.S. 5,260,491 , US 5 264 616, US 5 288 918, US 5 360 938, EP 472 071, EP 518 241 and WO 97/20795. In the case of the sterically hindered phosphites, the triphenyl phosphites substituted in each case 1 or 2 isopropyl and / or tert-butyl, preferably in the ortho position to the phosphite ester group, are to be mentioned. Other bisphosphite ligands are found, inter alia, in EP 1 099 677, EP 1 099 678, WO 02/00670, JP 10279587, EP 472017, WO 01/21627, WO 97/40001, WO 97/40002, US 4769498, EP 213639 and EP Called 214622.

Examples of phosphonites are methyldiethoxyphosphine, phenyldimethoxyphosphine, phenyldiphenoxyphosphine, 6-phenoxy-6H-dibenz [c, e] [1,2] oxaphosphorine and its derivatives in which the hydrogen atoms are completely or partially replaced by alkyl, aryl radicals or halogen atoms and ligands those in WO 98/43935, JP 09-268152 and DE 198 10 794 and in the German patent applications DE 199 54 721 and DE 199 54 510 to be discribed.

Common phosphinite ligands are among others in US 5 710 344 , WO 95 06627, US 5 360 938, JP 07082281. Examples include diphenyl (pherioxy) phosphine and its derivatives, in which the hydrogen atoms are replaced in whole or in part by alkyl, aryl or halogen atoms, diphenyl (methoxy) phosphine, diphenyl (ethoxy) phosphine, etc.

In the technical implementation of hydroformylation, the reaction product, unreacted starting material and catalyst are usually separated by distillation. The hydroformylation is therefore carried out in the presence of a high-boiling solvent, so that a high-boiling catalyst-containing fraction is obtained during the work-up by distillation and can be recycled into the process. In many technical, continuous hydroformylation processes in which rhodium catalysts are used, the high-boiling mixtures which are formed as a by-product of the hydroformylation are used as solvents, for example in DE 2 062 703 , DE 2 715 685, DE 2 802 922, EP 017183.

In addition to the high boilers, inert organic liquids ( DE 3 126 265 ) as well as reaction products (aldehydes, alcohols), aliphatic and aromatic hydrocarbons, esters, ethers and water ( DE 4 419 898 ) are used as solvents. In GB 1 197 902 saturated hydrocarbons, aromatics, alcohols and n-paraffins are used for this purpose.

Carrying out the hydroformylation with the addition of one or more polar organic substances z. B. in WO 01/68248, WO 01/68249, WO 01/68252. there polar substances are substances from the following classes of compounds: Nitriles, cyclic acetals, alcohols, pyrrolidones, lactones, formamides, Sulfoxides and water.

With the long chain hydroformylation Olefins (C ≥ 6) requires the separation of the catalyst from the reaction product by distillation and possibly the unreacted starting materials high temperatures and low Pressures. This results in a considerable decomposition of the rhodium-containing Catalyst instead, independently of whether an additional Ligand was used or not. The catalyst goes for the process lost, making the economics of the process drastic impaired becomes.

The unmodified rhodium catalysts prove to be particularly unstable. According to the unanimous opinion of experts, the mononuclear complex HRh (CO) ₃ , in the absence of modifying ligands, is the active species in hydroformylation. The complex HRh (CO) ₃ is only stable at temperatures below 20 ° C and high pressure (NS Imyanitov, Rhodium Express, (1995), 10/11, 3–64) and is in equilibrium with a binuclear species that is not itself active but serves as a reservoir for active catalyst (EV Slivinskii, YA Rozovskii, GA Korneeva, VI Kurkin, Kinetics and Catalysis (1998), 39 (6), 764 - 774) (AR El'man, VI Kurkin, EV Slivinskii, SM Loktev, Neftekhimiya (1990), 30 (1), 46-52). Starting from the bimolecular rhodium-carbonyl complex, hydroformylation-inactive clusters form with increasing molecular weight. Under the conditions of an intense hydroformylation reaction, the formation of the low-molecular clusters is reversible. It has been shown that clusters up to Rh ₄ (CO) ₁₂ can be regenerated. The stabilization of the active species under hydroformylation conditions could also be shown (Yu. B. Kagan, YA Rozovskii, EV Slivinskii, GA Korneeva, VI Kurkin, SM Loktev, Kinetika i Kataliz (1987), 28 (6), 1508-1511). Higher molecular clusters, on the other hand, cannot be converted back into active species under hydroformylation conditions (Yu. B. Kagan, EV Slivinskii, VI Kurkin, GA Korneeva, RA Aranovich, NN Rzhevskaya, SM Loktev, Neftekhimiya (1985), 25 (6), 791 - 797.). The formation of clusters is generally considered to be the cause and first step in the formation of solid rhodium-containing precipitates. It occurs during the working up by distillation, but in some cases also under reaction conditions. Precipitations containing rhodium are deposited on the container and tube walls. This leads to considerable economically disadvantageous catalyst losses and makes regular plant shutdowns and cleaning work necessary in technical applications. Rhodium precipitations have to be on metallurgical Ways to be regained with great effort.

Because of the attractiveness of the unmodified Rhodium as a hydroformylation catalyst on the one hand and its instability on the other are many processes for its circulation and / or reclamation been proposed.

A number of processes are known in which the rhodium species are removed from the reaction mixture by solid adsorbents. So z. B. in Scripture DE 19 54 315 Proposed as weakly to strongly basic ion exchange resins based on polystyrene. According to DE 20 45 416 can be carried out a regeneration of loaded ion exchange resins by treatment with mixtures of lower alcohols, aliphatic amines and water in the presence of oxygen. The rhodium contained in the eluate is converted into the rhodium chloride hydrate by concentration and treatment with hydrochloric acid, which can again be used as a catalyst precursor. The writings WO 02/20451 and US 5,208,194 claim the recovery of rhodium from loaded ion exchangers by burning them and isolating the rhodium as an oxide from the ashes. Iri US 4,388,279 Salts of the metals of the 1st and 2nd group of the Periodic Table of the Elements, zeolitic molecular sieves and ion exchange resins are proposed as adsorbents. WO 01/72679 claims a process for the adsorption of rhodium on activated carbon, polysilicic acids and aluminum oxides at elevated temperature in the presence of hydrogen. The patent EP 0 355 837 describes a process for the adsorption of rhodium on basic ion exchange resins which are modified with ionically bound organophosphorus ligands. The resin is regenerated by elution using a solution containing organophosphorus ligands. The document WO 97/03938 claims a process for the adsorption of active rhodium species and of impurities on acidic ion exchange resins. Regeneration takes place in the first step by eluting the impurities with a neutral solvent, then by eluting the active rhodium species with an acid solvent. The catalyst recovered in this way is used again in the hydroformylation, if appropriate after rehydration.

Common disadvantage of the adsorptive Rhodium recovery process is the unsatisfactorily resolved Task of releasing the active species. The specialist it is known that the solvents or solvent mixtures proposed for this purpose are not inert in the hydroformylation, but to side reactions to lead. Acidic solvents induce, for example, the highly exothermic and difficult to control Aldolization of the aldehydes. Alcohols and amines undergo condensation reactions with aldehydes and thus reduce the product yield. It is therefore imperative, before recycling the catalyst mentioned solvents or solvent mixtures to remove. This concept is technically extremely complex and expensive. On the other hand, adsorption has a certain industrial importance on ion exchangers with subsequent Ashing and metallurgical rhodium recovery achieved. This method is technically simple, but still needs improvement: it expensive basic ion exchanger is used as consumable and the ashing with subsequent Metallurgical processing of the metal oxides involves further extremely complex process steps connected.

In addition, a number of processes are known in which rhodium is extracted from the reactor discharge with solutions of different complexing agents and, after being released again, is returned to the hydroformylation reactor. For example, the rhodium-catalyzed hydroformylation in the presence of protonatable nitrogen-containing ligands, extraction of the rhodium complex with aqueous acid, deprotonation and recycling of the rhodium in the process DE 196 03 201 known. In DE 4 230 871 the aqueous solution is returned directly to the reaction. In EP 0 538 732 the extraction of the reactor discharge with aqueous phosphine solution under synthesis gas pressure is claimed. WO 97/03938 claims as a complexing agent water-soluble polymers such as polyacrylic acids, maleic acid copolymers and phosphonomethylated polyvinylamines, polyethyleneimines and polyacrylamides. EP 0 588 225 claims as complexing agents pyridines, quinolines, 2,2'-bipyridines, 1,10-phenanthrolines, 2,2'-bichinolines, 2,2 ', 6', 2 '' - terpyridines and porphyrins, optionally in sulfonated and / or carboxylated form. However, the complexing agents required for aqueous extraction are often expensive and difficult to access. In addition, these processes with two additional steps (extraction and catalyst release) require an increased technical outlay.

Furthermore, processes are known in which rhodium precipitates are to be prevented by adding phosphorus (III) -containing ligands in the classic distillative workup of the reactor discharge ( DE 33 38 340 , US 4,400,547). The hydroformylation-active rhodium species are regenerated or re-released by oxidation of the phosphorus (III) ligands. The disadvantage of this method is the continuous consumption of stabilizer. The resulting phosphorus (V) compounds must be continuously removed to prevent accumulation in the reactor system. In principle, part of the rhodium is also removed in active form. This process is therefore also technically and economically in need of improvement.

WO 82/03856 claims the distillation of the reactor effluent from the hydroformylation in the presence of oxygen. Under the action of oxygen, part of the aldehydes formed in the hydroformylation is oxidized to the corresponding carboxylic acids, which form with the rhodium species soluble rhodium carboxylates react. The rhodium carboxylates can be returned to the process. The disadvantage of this process is a reduced yield of valuable product.

In the not yet published application DE 102 40 253 describes the implementation of the hydroformylation in the presence of catalysts modified by phosphorus ligands and based on metals from group B to 10 of the Periodic Table of the Elements, cyclic carbonic acid esters being used as solvents. The use of unmodified metal complexes of the metals of the 8th to 10th group of the periodic table is not described.

JP 10-226662 describes a method described for the hydroformylation of olefinic compounds, in which a rhodium catalyst sulfonated with a sodium salt Triphenylphosphine as a cocatalyst, i.e. a modified catalyst is used. The reaction takes place in the presence of a polar component and a carboxylic acid carried out. As polar components such. B. also used ethylene carbonate become. The polar component together with the acid and be returned to the catalyst in the hydroformylation reaction. However, the process is only comparatively for hydroformylation reactive terminal olefins applicable. For internal and especially internally highly branched Olefins is the activity of the catalyst for an industrial application is far from sufficient.

The previously known methods for Recycling or recovery of rhodium from processes using unmodified rhodium as a hydroformylation catalyst use, are both technically and economically in need of improvement.

According to the state of the art there is no technically and economically satisfactory process for the hydroformylation of olefins which are difficult to oxidize, catalyzed by unmodified rhodium. So there was a task in this In terms of providing significantly improved method, especially a Process in which catalyst recovery is easy can, which is due to a significantly reduced catalyst deactivation distinguishes and thereby largely prevents catalyst losses can be.

It has now surprisingly been found that increased selectivity and activity in the hydroformylation of olefinically unsaturated compounds and the work-up of the reaction mixture can be facilitated and the catalyst stability significantly increased can be, if the catalyzed by unmodified rhodium Hydroformylation in the presence of cyclic carbonic acid esters as a solvent carried out becomes.

mit
R¹, R², R³, R⁴: jeweils gleich oder verschieden: H, substituierte oder unsubstituierte, aliphatische, alicyclische, aromatische, aliphatisch-alicyclische, aliphatisch-aromatische, alicyclisch-aromatische Kohlenwasserstoffreste mit 1 bis 27 C-Atomen.
n: 0–5 X: zweiwertiger substituierter oder unsubstituierter, aliphatischer, alicyclischer, aromatischer, aliphatisch-alicyclischer, aliphatisch-aromatischer Kohlenwasserstoffrest mit 1 bis 27 C-Atomen, durchgeführt wird, wobei der Anteil des Kohlensäureesters zumindest 1 Gew.-% des Reaktionsgemisches beträgt.The present invention accordingly relates to a process for the catalytic hydroformylation of olefinically unsaturated compounds having 3 to 24 carbon atoms, the catalyst used being an unmodified catalyst which comprises at least one metal from the 8th to 10th group of the Periodic Table of the Elements, which is characterized in that that the hydroformylation in the presence of at least one cyclic carbonic acid ester of the formula I

With
R ¹ , R ² , R ³ , R ⁴ : in each case the same or different: H, substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic, alicyclic-aromatic hydrocarbon radicals having 1 to 27 C atoms.
n: 0-5 X: divalent substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic hydrocarbon radical having 1 to 27 C atoms, the proportion of the carbonic acid ester being at least 1% by weight of the reaction mixture is.

Through the use according to the invention of carbonic acid esters as a solvent it is achieved that the hydroformylation in the presence of unmodified Catalyst, in particular rhodium catalyst can be carried out can, and the unmodified catalyst can be reused can.

The modified ligands already mentioned, which are usually used in rhodium-catalyzed hydroformylation, have a limited thermal stability, which generally limits the reaction temperature to 120 to 130.degree. In the implementation of difficult to oxidize ethylenically unsaturated compounds, such as. B. internal and especially internal highly branched olefins, show the ligand-modified rhodium catalysts at reaction temperatures caused by the thermal stability of the ligands are limited and the usual reaction pressures from 1 to 270 bar are technically insufficient activity.

However, unmodified rhodium indicates in the implementation of difficult to oxidize ethylenically unsaturated Connections a significantly higher activity on. However, the low thermal stability (N.S. Imyanitov, Rhodium Express, (1995), 10/11, 3-64). Examples of difficult oxiable ethylenically unsaturated Connections are internal and especially internally highly branched Olefins, which are contained in the isomer mixtures by Di- and oligomerization of propene and n-butene can be obtained as for example tripropen, tetrapropene, dibutene, tribute, tetrabutene and pentabutene.

The method according to the invention has in particular the advantage that the catalyst has increased long-term stability compared to catalysts has that in conventional solvents be used. Due to the solvent used, the It is easy to separate the catalyst from the reaction mixture because the catalyst independently on the type of workup (by distillation or by phase separation) in the Phase is present in which the cyclic used as solvent carbonate ester is available. This mixture can be used directly as a catalyst solution the hydroformylation reactor are driven: the separation of the Reaction discharge by phase separation into a product and unreacted starting material containing fraction and a fraction containing the catalyst is much gentler for the catalyst as a distillative workup. A thermal No load on the catalyst under reduced pressure, which is why the emergence of non-active metal catalyst species and metal-containing rainfall is avoided. Surprisingly also becomes a deactivation during separation by distillation by forming the non-active metal catalyst species and metal-containing rainfall largely prevented.

By the method according to the invention is it now possible the hydroformylation of internal olefins at temperatures up to 220 ° C and using catalysts with particularly high activity. On this way it is possible sales and selectivity hydroformylation, especially of internally highly branched olefins to increase.

The method according to the invention is as follows described by way of example without the invention being based on these examples embodiments limited should be. The person skilled in the art has further variants, which also Object of the present invention, the scope of application results from the description and the claims.

mit
R¹, R², R³, R⁴: jeweils gleich oder verschieden: H, substituierte oder unsubstituierte, aliphatische, alicyclische, aromatische, aliphatisch-alicyclische, aliphatisch-aromatische, alicyclisch-aromatische Kohlenwasserstoffreste mit 1 bis 27 C-Atomen.
n: 0-5
X: zweiwertiger substituierter oder unsubstituierter, aliphatischer, alicyclischer, aromatischer, aliphatisch-alicyclischer, aliphatischaromatischer Kohlenwasserstoffrest mit 1 bis 27 C-Atomen,
durchgeführt wird, wobei der Anteil des Kohlensäureesters zumindest 1 Gew.-% des Reaktionsgemisches beträgt.The process according to the invention for the catalytic hydroformylation of olefinically unsaturated compounds having 3 to 24 carbon atoms, in particular olefins, an unmodified catalyst having at least one metal from group B to 10 of the Periodic Table of the Elements being used as the catalyst, is characterized in that hydroformylation in the presence of at least one cyclic carbonic acid ester of the formula I.

With
R ¹ , R ² , R ³ , R ⁴ : in each case the same or different: H, substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic, alicyclic-aromatic hydrocarbon radicals having 1 to 27 C atoms.
n: 0-5
X: divalent substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic hydrocarbon radical with 1 to 27 C atoms,
is carried out, the proportion of the carbonic acid ester being at least 1% by weight of the reaction mixture.

The substituents R ¹ to R ⁴ and X can be identical or different and can be substituted by 0, N, NH, N-alkyl or N-dialkyl radicals. Furthermore, these radicals can carry functional groups such as, for example, halogens (fluorine, chlorine, bromine, iodine), -OH, -0R, -C (O) alkyl, -CN or -C (O) oalkyl. In addition, C, CH or CH ₂ radicals in these radicals can be replaced by 0, N, NH, N-alkyl or N-dialkyl radicals if they are at least three C atoms away from the 0 atom of the ester group. The alkyl groups can in turn contain 1 to 27 carbon atoms.

Ethylene carbo is preferred as the cyclic carbonic acid ester in the process according to the invention nat, propylene carbonate, butylene carbonate or mixtures thereof, such as a mixture ( 50 : 50% by weight) of ethylene carbonate and propylene carbonate.

In the method according to the invention, the proportion is the cyclic carbonic acid ester between 1 and 98% by weight, preferably between 5 and 70% by weight, however particularly preferably between 5 and 50% by weight of the reaction mass.

It is possible in addition to the cyclic Kohlensäureestern other solvents use. The hydroformylation reaction according to the invention is therefore used in special process variants in the presence of at least one with the cyclic carbonic acid ester I immiscible, non-polar solvent carried out. carbonate ester of formula I have a dielectric constant of over 30. The in the inventive method used, which are immiscible with the cyclic carbonic acid ester I, polar solvent have Dk values of less than 20, preferably from 1.1 to 10, particularly preferably from 1.1 to 5. By using additional, especially polar solvent can e.g. B. be set whether the reaction mixture and in particular the reactor discharge is single-phase or two-phase. So can if applicable, one provided in the processing of the reactor discharge Phase separation can be simplified. The reaction product of hydroformylation can with a polar and with the cyclic carbonic acid ester I immiscible solvents are extracted using the solvent already during the reaction may be present in the reaction mixture or only after completion added to the reaction can be.

Substituted or unsubstituted can be used as primary polar solvents Hydrocarbons with 10 to 50 carbon atoms such. B. the high-boiling by-products of the hydroformylation reaction, Texanol or the mixtures of isomers used in tetra- or pentamerization be obtained from proper or butene with subsequent hydrogenation, d. H. Tetrabutane, pentabutane, tetrapropane and / or pentapropane. It is also possible Olefins with 3 - 24 Carbon atoms, especially the one used for hydroformylation Olefin, as a very polar solvent to be used by the hydroformylation reaction not up to full sales carried out (e.g. only up to 95%, preferably 90%, particularly preferred 80%) and / or another olefin during and / or after the hydroformylation reaction, the reaction mixture is added.

In the method according to the invention, the proportion is the very polar solvent between 0 and 90% by weight, preferably between 5 and 50% by weight, particularly preferably between 5 and 30% by weight of the reaction mass.

To avoid by-products have to the polar solvents, if it is not the olefinically unsaturated compound used acts under the reaction conditions of the hydroformylation reaction be largely inert.

In the method according to the invention can the reaction mixture in the hydroformylation reactor be single or two-phase across the entire sales area. It is however also possible that the feed mixture is initially two-phase with low sales and in Course of the reaction at higher sales becomes single phase. It is possible, that a single-phase educt mixture during the implementation of the inventive method leads to a two-phase product mixture. In addition, the phase behavior strongly temperature dependent his. For example, a single phase at reaction temperature Reaction mixture on cooling disintegrate into two phases. A two-phase at reaction temperature The reaction mixture can also become homogeneous on cooling.

The process according to the invention can be carried out with various catalytically active metals from groups B to 10 of the Periodic Table of the Elements, but preferably with rhodium. In the context of the present invention, unmodified catalysts comprising metals from group B to group 10 of the Periodic Table of the Elements are understood to mean catalysts which have no modifying ligands. For the purposes of this application, modifying ligands are to be understood as compounds which contain one or more donor atoms from the 15th group of the Periodic Table of the Elements. However, the modifying ligands should not be carbonyl, hydrido, alkoxy, alkyl, aryl, allyl, acyl or alkene ligands, and the counterions of the metal salts used for catalyst formation, e.g. B. halides such as fluoride, chloride, bromide or iodide, acetylacetonate, carboxylates such as acetate, 2-ethylhexanoate, hexanoate, octanoate or nonanoate. A particularly preferred unmodified catalyst is HRh (CO) ₃ .

The active catalyst complex for the hydroformylation reaction is from a salt or a compound of the metal (catalyst precursor) and Syngas formed. Happily happens this in situ during hydroformylation. usual catalyst precursor are Rh (I), Rh (II) and Rh (III) salts, for example acetates, Octanoates, nonanoates, acetylacetonates or halides and the Rhodium carbonyls. The concentration of the metal in the reaction mixture is preferably in the range from 1 ppm to 1000 ppm, preferably in the range of 5 ppm to 300 ppm.

The starting materials for a hydroformylation according to the process of the invention are compounds which contain ethylenically unsaturated CC double bonds, in particular olefins or mixtures of olefins, in particular monoolefins having 3 to 24, preferably 4 to 16, particularly preferably 4 to 12 carbon atoms with terminal or internal CC double bonds, such as. B. 1- or 2-pentene, 2-methylbutene-1, 2-methyl buten-2, 3-methylbutene-1, 1-, 2- or 3-hexene, the C ₆ -olefin mixture (dipropene) resulting from the dimerization of Proper, heptenes, 2- or 3-methyl-l-hexene, octenes, 2-methylheptene, 3-methylheptene, 5-methylheptene-2, 6-methylheptene-2, 2-ethylhexene-1, the isomer C ₈ -olefin mixture obtained in the dimerization of n-butenes (dibutene), which in the dimerization of iso -Butene C ₈ -olefin mixture (di-isobutene), nonenes, 2- or 3-methyloctenes, the C ₉ -olefin mixture (tripropen) resulting from the trimerization of propene, decenes, 2-ethyl-l-octene, dodecenes , the C ₁₂ -olefin mixture resulting from the tetramerization of propene or the trimerization of butenes (tetrapropene or tributes), tetradecenes, hexadecenes, the C ₁₆ -olefin mixture resulting from the tetramerization of butenes (tetrabutene) and by cooligomerization of olefins with different numbers of Carbon atoms (preferably 2 to 4) olefin mixtures prepared, optionally by distillation r Separation into fractions with the same or similar chain length. It is also possible to use olefins or olefin mixtures which have been obtained by Fischer-Tropsch synthesis, and olefins which have been obtained by oligomerizing ethene or olefins which are accessible via methathesis reactions. Preferred educts are C ₄ -, C ₆ -, C ₈ -, C ₉ -, C _{1 2} - or C ₁₆ -olefin mixtures. The inventive method can also be used for the hydroformylation of polymeric olefinically unsaturated compounds such as polyisobutene or 1,3-butadiene or isobutene copolymers. The molar mass of the polymeric olefins is irrelevant, the olefin only has to be sufficiently soluble in the hydroformylation medium. The molar mass of the polymeric olefins is preferably below 10000 g / mol, particularly preferably below 5000 g / mol.

The volume ratio of carbon monoxide to Hydrogen in the synthesis gas is generally in the range of 2: 1 up to 1: 2, especially with a volume ratio of 1: 1. The synthesis gas is advantageously in excess, for example up to three times the stoichiometric Amount used.

The hydroformylations are in usually when pressed carried out from 1 to 350 bar, preferably at pressures from 15 to 270 bar. The pressure applied depends on the structure of the insert olefins, the catalyst used and the desired effect. For example a-olefins under rhodium catalysis at pressures below 100 bar with high Space-time yields are converted to the corresponding aldehydes. For olefins with internal Double bonds, in particular in the case of branched olefins, on the other hand, higher pressures are appropriate.

The reaction temperatures of the process according to the invention are preferably from 20 to 220 ° C, preferably from 100 ° C to 200 ° C, preferably of 150 ° C up to 190 ° C, particularly preferably from 160 to 180 ° C. By a reaction temperature from above 150 ° C can especially the relationship from terminal to internal Double bonds can be improved since accelerated at higher temperatures Isomerization more terminal Double bonds available be put and thus a hydroforinylation in the preferred terminal Position increasingly takes place.

The process according to the invention can be carried out batchwise (batchwise) or continuously. Is preferred however, a continuous mode of operation. As reactors are practical all gas-liquid reactors known to the person skilled in the art are suitable, for example fumigated stirred tank or bubble columns as well as tubular reactors with or without return. Cascaded are preferred bubble columns and tubular reactors with static mixing elements.

The in the method according to the invention obtained reactor discharge may have unreacted olefinic unsaturated Compound (olefins), reaction products, reaction by-products, at least one cyclic carbonic acid ester, possibly a very polar one solvent and the catalyst. Depending on the type and mass fraction of the input material olefinic compound (s) used, type and mass fraction of the any polar solvent present and the type and mass fraction of the cyclic carbonic acid ester the reactor discharge can be single or two-phase. As above mentioned can by appropriate additions of cyclic carbonic acid esters or polar solvent phase separation can be achieved or prevented.

Processing the reactor discharge in the process according to the invention, depending on the phase behavior of the reactor discharge, in two variants respectively. In the case of a two-phase reactor discharge, one is preferred Refurbishment over Phase separation according to Variant A, preferably one for a single-phase reactor discharge Working up by distillation according to variant B used.

It can be beneficial if after most of the hydroformylation of the synthesis gas is removed by depressurization before the further processing of the reactor discharge according to variant A or B takes place.

Variant A In this process variant becomes the two-phase reactor discharge of the hydroformylation reaction preferably by separating the phases into a predominantly the catalyst and the one or more cyclic carbonic acid esters and one predominantly the hydroformylation products and unreacted olefins or olefinically unsaturated Fraction containing compounds separated.

This process variant is suitable when using an optional further non-polar solvent. The non-polar solvent can also be identical to the feed olefin, so that either the hydroformylation reaction is not carried out until conversion is complete (e.g. only up to 95%, preferably 90%, particularly preferably 80%) and / or further olefin during and / or after hydroformy lation reaction is added to the reaction mixture.

The variant A of the method according to the invention is by 1 explained in more detail without the method being restricted to this embodiment variant: synthesis gas ( 1 ), Olefins ( 2 ) and hydroformylation catalyst dissolved in cyclic carbonic acid ester or a mixture of several cyclic carbonic acid esters ( 3 ) are in the hydroformylation reactor ( 4 ) implemented. The reactor discharge ( 5 ) can optionally in a relaxation tank ( 6 ) of the excess synthesis gas ( 7 ) are exempted. The material flow thus obtained ( 8th ) is preferred in a separation apparatus ( 9 ) in a difficult phase ( 10 ), which contains most of the cyclic carbonic acid ester and the catalyst as well as high-boiling by-products and a light phase ( 11 ), which contain the hydroformylation products, unreacted olefin and optionally the non-polar solvent. The phase separation can be carried out at temperatures from 0 ° C. to 130 ° C., but preferably between 10 ° C. and 60 ° C. The phase separation can e.g. B. be carried out in a settler container. The phase separation in the separating apparatus ( 9 ) under synthesis gas at a pressure of 1 to 350 bar, preferably at 15 to 270 bar, but particularly preferably at the same pressure as in the hydroformylation reactor ( 4 ) is applied. The separation apparatus ( 9 ) can optionally use a heat exchanger to cool the material flow ( 5 ) upstream (in 1 Not shown). In an optional separation stage ( 12 ) catalyst residues from the stream ( 11 ) can be removed. Material flow ( 11 ) or (13) are now the separation stage ( 14 ) fed. Here the reaction products (aldehydes and alcohols) and unreacted olefins ( 15 ) separated and fed to a further workup or hydrogenation. That from the material flow ( 15 ) separated olefin can be fed into the same reactor or into an optional second reaction stage. The fraction also separated ( 16 ) contains e.g. B. residues of the cyclic carbonic acid ester, the reaction products, any other non-polar solvents added and high-boiling by-products. Fraction ( 16 ) can be in the hydroformylation reactor ( 4 ) are discarded or returned. Before the return, it is expedient to carry out a workup in which undesired by-products are removed. The catalyst separation in the separation apparatus ( 9 ) can be carried out as an extraction in which at least part of the fraction ( 16 ) and / or at least part of the fresh olefin ( 2 ) directly to the material flow ( 8th ) is supplied. The extraction is preferably carried out continuously, it can be single-stage or can be operated as a multi-stage process in countercurrent, countercurrent or crossflow. catalyst-containing discharge streams, such as from the stream ( 10 ) or the separation stage ( 12 ), can be worked up on the catalyst metal in a recyclable form by known processes.

Variant B

In this variant of the method the homogeneous reactor discharge of the hydroformylation reaction Distillation in a low-boiling, predominantly the hydroformylation products and possibly unreacted olefins or olefinically unsaturated compounds containing fraction and one, predominantly cyclic carbonic acid ester and high-boiling catalyst Fraction separated.

Variant B of the method according to the invention is represented by 2 explained in more detail without the method being restricted to this embodiment variant: synthesis gas ( 1 ), Olefins ( 2 ) and hydroformylation catalyst, dissolved in cyclic carbonic acid ester or a mixture of several cyclic carbonic acid esters ( 3 ), are in the hydroformylation reactor ( 4 ) implemented. The reactor discharge ( 5 ) can optionally in a relaxation tank ( 6 ) of the excess synthesis gas ( 7 ) are exempted. The material flow thus obtained ( 8th ) is placed in a separator ( 9 ) and distilled into a high-boiling fraction ( 10 ), which contains most of the cyclic carbonic acid ester and the catalyst and a low-boiling phase ( 11 ), which contains the hydroformylation products, unreacted olefin and possibly non-polar solvent. The catalyst-containing fraction ( 10 ) is returned to the hydroformylation reactor. Before this, a work-up step can optionally be carried out in which high-boiling by-products and / or catalyst degradation products are discharged (in 2 Not shown). Fraction ( 11 ) can optionally in a separation step ( 12 ) are still free of catalyst residues. The current 13 then the distillation stage ( 14 ) fed. Here the hydroformylation products (aldehydes and alcohols) ( 16 ) by distillation from the unreacted olefin ( 15 ) Cut. catalyst-containing discharge streams, such as from the stream ( 10 ) or the separation stage ( 12 ), can by methods that the expert z. B. from WO 02/20451 or US 5,208,194 are known to be worked up on the catalyst metal in a recyclable form. The hydroformylation products can then be worked up further.

Unreacted olefin ( 15 ) can be carried out in the same hydroformylation reactor or in an optional second reaction stage. Different variants can be used in the technical design of the separators. Separation via falling film, short-range or thin-film evaporators or combinations of these apparatuses is preferred. The advantage of such a combination can be, for example, that in a first step still dissolved synthesis gas as well as most of the products and unreacted starting materials are separated from the alkylene carbonate solution containing the catalyst (for example in a falling film evaporator or flash evaporator) and then in a second Step (for example in a comm combination of two columns), the separation of the remaining alkylene carbonates and the separation of products and unreacted starting materials.

The two versions A and B of the method according to the invention obtained, from catalyst, excess synthesis gas and most of it of the solvent (i.e. the cyclic carbonic acid ester or a mixture of several) exempted reactor discharges preferably further in aldehydes (alcohols), olefins, solvents and by-products separated. As is known, this can e.g. B. by Distillation happen. From the reaction discharge or the hydroformylation products separated olefin and / or solvent (Alkylene carbonate and / or non-polar solvent) can be used in the hydroformylation reaction be returned.

The mentioned variants of the process according to the invention include the separation of the reactor discharge and optionally the hydroformylation products; this can be done for example by distillation. In addition, however, the use of other separation processes such. B. the extraction, such as in WO 01/68247, EP 0 922 691 , WO 99/38832, US Pat. No. 5,648,554 and US Pat. No. 5,138,101 or permeation, as described, inter alia, in DE 1953641, GB 1312076, NL 8700881, DE 3842819, WO 9419104, DE 19632600 and EP 1 103 303. Various procedures can be used for the technical implementation of the separation. Separation via falling film, short-range or thin-film evaporators or combinations of these apparatuses is preferred. The extractive separation is advantageously carried out continuously. It can be carried out as a single-stage process or can be operated as a multi-stage process in counterflow or crossflow.

In all process variants expedient way the fraction containing the catalyst in the hydroformylation reaction recycled. This is self-evident independently the composition of the fractions in which the catalyst is dissolved.

If not the aldehydes themselves, but the alcohols derived from them are target products, the of synthesis gas and catalyst and optionally of solvent liberated reaction discharge is hydrogenated before or after olefin removal and then by distillation be worked up on pure alcohol.

The method according to the invention can be used carried out in several stages become. Here it is possible after a first hydroformylation reaction, a second hydroformylation stage to go through the more drastic reaction conditions (to Example higher Temperature and / or higher Pressure) also the difficult to hydroformylate, internal, especially the internally highly branched Olefins to the desired ones Aldehydes. However, a separation of not is preferred initially converted olefins and hydroformylation products (aldehydes and alcohols) and the unreacted olefins in the same hydroformylation step returned or a second hydroformylation stage or still further hydroformylation stages fed. It is also possible a completely different catalyst system in the second hydroformylation stage, i.e. another catalyst metal or a ligand-modified one Catalyst metal to use. It may also be useful the unreacted olefins therein a higher concentration of catalyst inflict, in order to achieve even more difficult hydroformylatable olefins To implement products. In all cases it is necessary in the further hydroformylation stages cyclic carbonic acid ester add in the amounts mentioned.

In the method according to the invention can as olefinically unsaturated Connections are also used as unreacted olefinically unsaturated Compounds from the reactor discharge of a first hydroformylation reaction were obtained. The entire reaction discharge or only a part of it, especially a part that is not the predominant part of the has converted olefinic compounds from the first stage, be used. It can be quite beneficial if with this Process variant the first hydroformylation reaction in the presence of a ligand-modified catalyst.

The following examples are intended only for explanation serve the invention, but not restrict its scope, which yourself results from the description and the claims.

Example 1 (variant A)

560 g of propylene carbonate, 560 g of tri-n-butene and 0.0888 g or 0.0225 g of rhodium (II) nonanoate were placed in a 2 l stirred autoclave under a nitrogen atmosphere, which corresponds to a rhodium concentration of 5 ppm or 20 ppm rhodium on the mass of the reactor contents. The autoclave was then charged with synthesis gas (CO / H ₂ 1: 1 molar) and heated to the desired reaction temperature. The reactor pressure was checked during the heating ice. The reaction temperatures were from 130 ° C to 180 ° C. The reaction pressure was 260 bar. During the reaction, synthesis gas was run under pressure control. After 5 hours the experiment was stopped and the reactor cooled to ambient temperature. The reactor discharge was always two-phase and free of rhodium precipitates.

The composition of the lighter hydrocarbon separated in a phase separation tank The substance phase was determined by means of gas chromatography. The results of gas chromatography and the reaction conditions such as temperature and rhodium concentration are summarized in Table 1.

Table 1

Hydroformylation of tri-n-butene at 260 bar and different temperatures for 5 hours

The specified proportions (in mass%) refer to the composition of the lighter hydrocarbon phase, if any carbonate ester and catalyst present are excluded were. In experiment 6, the process of working up the reactor discharge catalyst solution obtained from experiment 5 used again.

example 2 (Variant B)

Analogous to example 1 di-n-butene (560 g) was hydroformylated. The reactor discharges from the 5 experiments 7 to 13 were always single-phase and free of (rhodium) precipitates. In contrast to the example 1 the reactor discharge was analyzed by gas chromatography without working up. The results of gas chromatography and the reaction conditions such as temperature, pressure and rhodium concentration are summarized in Table 2.

Table 2

Hydroformylation of di-n-butene at different pressures, Rhodium concentrations and temperatures

The specified proportions (in mass%) relate to the composition of the reactor discharge, where existing carbonic acid ester and catalyst have been removed.

example 3 (conventional approach)

As in example 2 di-n-butene was hydroformylated with the difference that pentabutane was used as the solvent instead of propylene carbonate. The reactor discharge from the experiment 14 already showed clear black (rhodium) precipitates. The aldehydes and unreacted olefins were then separated off from the catalyst-containing solution on a thin-layer evaporator, which was used in a renewed hydroformylation (experiment 15 ). The results of gas chromatography and the reaction conditions such as temperature, pressure and rhodium concentration are summarized in Table 2 5.

Table 3

Hydroformylation of di-n-butene at 150 ° C and 250 bar in pentabutane. The proportions given (in% by mass) relate to the composition of the reactor discharge, pentabutane, by-product and catalyst present being excluded. In trial 15 was the experiment in the reprocessing by distillation 14 catalyst solution obtained used again.

The absence of any rhodium precipitation in the experiments 1 to 13 indicates that 15 the alkylene carbonate used as solvent can stabilize rhodium compounds in a special way. In contrast, considerable rhodium precipitations and a drastic loss of activity in the catalyst recycling are observed in the comparative experiment using an alkane as solvent (experiment 14 and 15 ). In trial 6 became the catalyst phase from experiment 5 used in a renewed hydroformylation. As part of 20 the experimental accuracy, the olefin conversion remains constant.

The tests prove that the method according to the invention a significantly higher one Chemoselectivity too the wished Aldehydes offers and about In addition, a technically simple catalyst recycle without significant deactivation allowed.

Claims (12)

Process for the catalytic hydroformylation of olefinically unsaturated compounds having 3 to 24 carbon atoms, the catalyst used being an unmodified catalyst comprising at least one metal from the 8th to 10th group of the Periodic Table of the Elements, characterized in that the hydroformylation is carried out in the presence of a cyclic carbonic acid ester of formula I.

with R ¹ , R ² , R ³ , R ⁴ : in each case the same or different: H, substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic, alicyclic-aromatic hydrocarbon radicals having 1 to 27 carbon atoms. n: 0-5 X: divalent substituted or unsubstituted, aliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic hydrocarbon radical with 1 to 27 C atoms, the proportion of the carbonic acid ester being at least 1% by weight of the reaction mixture. A method according to claim 1, characterized in that R ¹ , R ² , R ³ , R ⁴ and X are identical or different by 0, N, NH, N-alkyl or N-dialkyl radicals, fluorine, chlorine, bromine, iodine, OH, -OR, -CN, -C (O) alkyl or -C (O) O-alkyl are substituted. Method according to one of claims 1 or 2, characterized in that that the hydroformylation in the presence of 5 to 50 wt .-% based on the reaction mass of a compared to the cyclic carbonic acid ester I, non-polar and immiscible with the cyclic carbonic acid ester I. solvent is carried out. Method according to one of claims 1 to 3, characterized in that that the reaction product of hydroformylation with a non-polar and with the cyclic carbonic acid ester I immiscible solvent is extracted. A method according to claim 3 or 4, characterized in that as a polar solvent Substituted or substituted hydrocarbons with 10 to 50 carbon atoms or olefins of 3 to 24 carbon atoms be used. Method according to one of claims 1 to 5, characterized in that the hydroformylation is carried out in the presence of HRh (CO) ₃ as a catalyst. Method according to one of claims 1 to 6, characterized in that that the reaction discharge of the hydroformylation reaction into a predominantly containing the catalyst and the cyclic carbonic acid ester and one predominantly the fraction containing hydroformylation products is separated. Method according to one of claims 1 to 7, characterized in that that the fraction containing the catalyst into the hydroformylation reaction is returned. Method according to one of claims 1 to 8, characterized in that that as a cyclic carbonic acid ester Ethylene carbonate, propylene carbonate or butylene carbonate or their Mixtures are used. Method according to one of claims 1 to 9, characterized in that that the unreacted olefinically unsaturated compounds from the Reactor discharge or separated from the hydroformylation products and recycled to the same hydroformylation reaction or to a second hydroformylation reaction guided become. Method according to one of claims 1 to 10, characterized in that that as olefinically unsaturated Connections are used as unconverted olefinically unsaturated Compounds from the reactor discharge of a first hydroformylation reaction were obtained. A method according to claim 11, characterized in that as olefinically unsaturated compounds those are used which were obtained as unreacted olefinically unsaturated compounds from the reactor discharge of a first hydroformylation reaction which was carried out in the presence of a ligand-modified catalyst.