RU-catalyzed domino hydroformylation / hydration / esterification using phosphone ligands

Description

[0001] The present invention relates to a Ru-catalyzed domino hydroformylation / hydrogenation / esterification using phosphine ligands.

[0002] EP 0 329 252 B1 describes a process for the production of carboxylic acids or esters. This process is catalyzed by the use of a ruthenium compound in combination with an acidic compound. The acidic compound comprises one of the following elements: phosphorus, antimony, arsenic, molybdenum, or tungsten. US 3 168 553 A describes an alkoxycarbonylation process for the production of ethyl propionate.

[0003] In I. Fleischer, KM Dyballa, R. Jennerjahn, R. Jackstell, R. Franke, A. Spannenberg, M. Beller, "From Olefins to Alcohols: Efficient and Regioselective Ruthenium-Catalyzed Domino Hydroformylation / Reduction Sequence", Angew. Chem. Int. Ed. 2013, 52, 2949-2953, a process for hydroformylation and subsequent reduction is described. The olefin used is converted to the aldehyde and finally reduced to the alcohol.

[0004] The technical problem underlying the present invention is to provide a process that leads directly to an ester from an olefin without isolating intermediates. The original olefin is intended to form the alcohol moiety of the ester, i.e., it is bonded via the oxygen atom to the carbon atom of the C=O group. Furthermore, the alcohol moiety of the ester is intended to have one more carbon atom than the olefin used.

[0005] This problem is solved by a method according to claim 1.

[0006] The procedure encompasses the following procedural steps: a) Providing an ethylene unsaturated compound; b) Adding a ligand according to formula (I): where R1<, R2<, R3< are selected from: -(C1-C12)-alkyl, -(C6-C12)-cycloalkyl, -(C6-C20)-aryl, wherein the -(C6-C12)-cycloalkyl group and the -(C6-C20)-aryl group may have substituents selected from: -(C1-C12)-alkyl, -O-(C1-C12)-alkyl, -SO3Na; and a compound comprising Ru; c) addition of an acid (II) having formula (IIa) or (IIb): where R 4< stands for -(C 1 -C 18 )-alkyl; where R 5< represents -(C 1 -C 18 )-alkyl; d1) supply of CO; d3) addition of H 2 O, wherein H 2 O is added in an amount such that the molar ratio of H 2 O to the ethylene unsaturated compound is in the range of 1:1 to 10:1; e) heating of the reaction mixture from a) to d), wherein the ethylene unsaturated compound is directly converted to an ester or diester of acid (II) without isolation of intermediates.

[0007] Here, d) includes the procedural steps d1) and d3), and, if applicable, the further procedural steps d2) and d4).

[0008] The process steps a), b), c), and d) can be carried out in any order. However, CO is usually added after the reactants have been introduced in steps a) to c). Steps d) and e) can be carried out simultaneously or sequentially. Furthermore, CO can also be added in several steps, for example, by first adding some CO, then heating it, and then adding another portion.

[0009] The term (C1-C12)-alkyl encompasses straight-chain and branched alkyl groups with 1 to 12 carbon atoms. Suitable (C1-C12)-alkyl groups include, in particular, methyl, ethyl, propyl, and isopropyl. n -Butyl, ISO -Butyl, sec -Butyl, tert -Butyl, n-Pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-Dimethylbutyl, 2,2-Dimethylbutyl, 1,3-Dimethylbutyl, 2,3-Dimethylbutyl, 3,3-Dimethylbutyl, 1,1,2-Trimethylpropyl, 1,2,2-Trimethylpropyl, 1-Ethylbutyl, 1-Ethyl-2-methylpropyl, n -Heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n -Octyl, 2-Ethylhexyl, 2-Propylheptyl, Nonyl, Decyl.

[0010] The term (C 6 -C 12 )-cycloalkyl includes mono-, bi- or tricyclic hydrocarbon groups.

[0011] The term (C6-C20)-aryl encompasses mono- or polycyclic aromatic hydrocarbon residues with 6 to 20 carbon atoms. Preferably, these are (C6-C14)-aryls, and particularly preferably (C6-C10)-aryls.

[0012] Suitable (C6-C20) aryl groups are, in particular, phenyl, naphthyl, indenyl, fluorenyl, anthracenyl, phenanthrenyl, naphthacenyl, chrysenyl, pyrenyl, and coronenyl. Preferred (C6-C20) aryl groups are phenyl, naphthyl, and anthracenyl.

[0013] The ethylene-unsaturated compounds used as starting materials in the process according to the invention contain one or more carbon-carbon double bonds. For simplicity, these compounds are hereinafter referred to as olefins. The double bonds can be terminal or internal. Preferably, the ethylene-unsaturated compounds have one carbon-carbon double bond.

[0014] Preferably ethylene-unsaturated compounds with 2 to 30 carbon atoms, preferably 2 to 22 carbon atoms, particularly preferably 2 to 12 carbon atoms.

[0015] In one embodiment, the ethylene unsaturated compound is selected from: ethene, propene, 1-butene, cis and / or trans-2-butene, iso-butene, 1,3-butadiene, 1-pentene, cis-and / or trans-2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, hexene, tetramethylethylene, heptene, 1-octene, 2-octene, di-n-butene, or mixtures thereof.

[0016] In one embodiment, R 1< is selected from: -(C 1 -C 12 )-alkyl, -(C 6 -C 20 )-aryl, -(C 5 -C 20 )-heteroaryl.

[0017] In one embodiment, R 1< , R 2< , R 3< are selected from: -(C 6 -C 12 )-Cycloalkyl, -(C 6 -C 20 )-Aryl.

[0018] In one embodiment, R 1< , R 2< , R 3< represent -(C 6 -C 12 )-cycloalkyl.

[0019] In one embodiment, R 1< , R 2< , R 3< represent -Cy.

[0020] In one embodiment, R 1< , R 2< , R 3< represent -(C 6 -C 20 )-Aryl.

[0021] In one embodiment, R 1< , R 2< , R 3< represent -Ph.

[0022] In one embodiment, R 1< , R 2< , R 3< represent the same remainder.

[0023] In one embodiment, the compound comprising Ru is selected from: Ru 3 (CO) 12 , RuCl 3 *H 2 O, Ru(Cl) 2 (DMSO) 4 , Ru(acac) 3 .

[0024] In one embodiment, the compound comprising Ru is Ru 3 (CO) 12 .

[0025] In one embodiment, R 4< stands for -(C 1 -C 12 )-alkyl.

[0026] In one embodiment, R 4< stands for -(C 1 -C 8 )-alkyl.

[0027] In one embodiment, R 5< stands for -(C 1 -C 12 )-alkyl.

[0028] In one embodiment, R 5< stands for -(C 1 -C 8 )-alkyl.

[0029] In one embodiment, the method includes the additional process step d2): d2) supplying H 2 .

[0030] In one embodiment, the H2 pressure is in the range of 1 MPa (10 bar) to 6 MPa (60 bar).

[0031] In one embodiment, the process includes the additional process step d4): d4) Addition of para-toluenesulfonic acid.

[0032] In one embodiment, the acid (II) is added in process step c) in an amount such that the molar ratio of acid to the ethylene unsaturated compound is in the range of 2:1 to 10:1.

[0033] In one embodiment, the acid (II) has the formula (IIa).

[0034] In one embodiment, the acid (II) has the formula (IIb).

[0035] In one embodiment, the ligand in process step b) is selected from:

[0036] In one embodiment, the reaction mixture is heated in process step e) to a temperature between 50 °C and 180 °C, preferably between 80 °C and 160 °C, particularly preferably between 100 °C and 150 °C, in order to convert the ethylene unsaturated compound to the ester.

[0037] The invention will be described in more detail below using exemplary embodiments. General work regulations

[0038] All work with air- and moisture-sensitive substances was carried out in an argon atmosphere using baked-out glassware and the Schlenk technique. Chemicals were obtained from commercial manufacturers and used as supplied, provided the purity was at least 98%. Oxygen-free and dry solvents were prepared by distillation under argon. Synthesis gas (CO: 99.997%, H₂ / CO: 1:1 ±1%) was obtained from Linde.

[0039] The products were analyzed by <1H NMR and <13C NMR spectroscopy. NMR spectra were recorded on Bruker AV 400 (400 MHz), Bruker AV 300 (300 MHz), or Fourier 300 (MHz) instruments. Chemical shifts δ (ppm) are given relative to the solvent used: reference values ​​for CDCl3 were 7.26 ppm (<1H NMR) and 77.16 ppm (<13C NMR). <13C NMR spectra were recorded using a broadband decoupling method.

[0040] GC analyses were performed on an Agilent Technologies 7890A GC system using a 30 mH-5 column. Argon was used as the carrier gas. Products were analyzed by GC or GC-MS or isolated by column chromatography (silica, EtOAc / heptane). GC yields were calculated via internal calibration. Hexadecane was used as the internal standard. Conducting the catalytic experiments

[0041]

[0042] The catalytic experiments were performed in 4 mL glass vials with screw caps and a PTFE septum. Oven-dried magnetic stirrers were fitted into the vials, and a needle was used to connect them to the gas atmosphere. The reaction mixture consisted of 2 mL. The vials were placed in a 300 mL Parr4560 autoclave and stirred over a magnetic stirrer. In the first step, Ru3(CO)12 (5 mol%), ligand (5.5 mol%), and PTSA*H₂O (20.6 mol%) were weighed into the vial. The vial was sealed with a screw cap containing a septum and connected to the argon atmosphere via a cannula. The vial was secured and purged with argon three times. Acetic acid (1.17 mL), H₂O (0.35 mL), and 1-octene (3 mmol) were injected using a Hamilton syringe. Under an argon atmosphere, the vial was transferred to the autoclave. The autoclave was then tightly sealed and initially purged three times with 10 bar CO₂ at room temperature.Then, 40 bar of CO₂ was applied, the autoclave was placed in an aluminum block on a magnetic stirrer, and heated to 140 °C for 20 h. After 20 h, the autoclave was cooled to room temperature and the pressure was carefully released. 100 µL of hexadecane was added to the reaction solution as an internal standard. The yield was determined by GC analysis.

[0043] The reaction was performed under analogous conditions for the ligands (1) until (3), as well as for the comparison league team (4) carried out. Since the comparison ligand (4) Since a bidentate ligand was involved, only 2.75 mol% was used instead of 5.5 mol%. To obtain a constant molar ratio of PTSA*H₂O:L (3.75:1), the amount was then reduced to 10.3 mol%. Reaction conditions

[0044] 1-Octene: 3 mmol Ru 3 (CO) 12: 5 mol% Ru ligand (1) until (3):5.5 mol% based on 1-octene ligand (4): 2.75 mol% based on 1-octene PTSA*H₂O using (1) to (3): 20.6 mol% PTSA*H₂O using (4): 10.3 mol% H₂O : 1-Octene = 6.5 : 1 (molar ratio) HOAc : 1-Octene = 6.75 : 1 (molar ratio) CO pressure: 40 bar Temperature: 140 °C Reaction time: 20 h Test results

[0045] Ligand Ester yield [%] ( 1 )* 24 ( 2 )* 25 ( 3 )* 23 ( 4 ) 10 * inventive method

Claims

1. Process comprising the process steps of: a) initially charging an ethylenically unsaturated compound; b) adding a ligand of formula (I): wherein R1, R2, R3 are selected from: -(C1-C12)-alkyl, -(C6-C12)-cycloalkyl, -(C6-C20)-aryl, wherein the -(C6-C12)-cycloalkyl radical and the -(C6-C20)-aryl radical may have substituents which are selected from: -(C1-C12)-alkyl, -O-(C1-C12)-alkyl, -SO3Na; and a compound comprising Ru; c) adding an acid (II) having the formula (IIa) or (IIb) : wherein R4 is -(C1-C18)-alkyl; wherein R5 is -(C1-C18)-alkyl; d1) supplying CO; d3) adding H2O, wherein H2O is added in an amount such that the molar ratio of H2O to the ethylenically unsaturated compound is in the range from 1:1 to 10:1; e) heating the reaction mixture from a) to d) to convert the ethylenically unsaturated compound directly into an ester or diester of acid (II) without isolation of intermediates.

2. Process according to Claim 1, wherein the ethylenically unsaturated compound is selected from: ethene, propene, 1-butene, cis- and / or trans-2-butene, isobutene, 1,3-butadiene, 1-pentene, cis- and / or trans-2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, hexene, tetramethylethylene, heptene, 1-octene, 2-octene, di-n-butene, or mixtures thereof.

3. Process according to either of Claims 1 or 2, wherein R1, R2, R3 are selected from: -(C6-C12)-cycloalkyl, -(C6-C20)-aryl.

4. Process according to any of Claims 1 to 3, wherein R1, R2, R3 are the same radical.

5. Process according to any of Claims 1 to 4, wherein the compound comprising Ru is selected from: Ru3(CO)12, RuCl3*H2O, Ru(Cl)2(DMSO)4, Ru(acac)3.

6. Process according to any of Claims 1 to 5, wherein R4 is -(C1-C12)-alkyl.

7. Process according to any of Claims 1 to 6, wherein R5 is -(C1-C12)-alkyl.

8. Process according to any of Claims 1 to 7, comprising the additional process step d2): d2) supplying H2.

9. Process according to Claim 8, wherein the H2 pressure is in the range from 1 MPa (10 bar) to 6 MPa (60 bar).

10. Process according to any of Claims 1 to 9, comprising the additional process step d4): d4) adding para-toluenesulfonic acid.

11. Process according to any of Claims 1 to 10, wherein the acid (II) is added in process step c) in an amount such that the molar ratio of acid to the ethylenically unsaturated compound is in the range from 2:1 to 10:1.

12. Process according to any of Claims 1 to 11, wherein the acid (II) has the formula (IIa).

13. Process according to any of Claims 1 to 12, wherein the ligand in process step b) is selected from: