DIPHOSPHITE MIT DICYCLOHEXYLPHOSPHINOREST

Description

[0001] The invention relates to diphosphites with dicyclohexylphosphino radical and their use in hydroformylation.

[0002] Phosphorus-containing compounds play a crucial role as ligands in a variety of reactions, e.g. in hydrogenation, hydrocyanation and also in hydroformylation.

[0003] The reaction between olefin compounds, carbon monoxide, and hydrogen in the presence of a catalyst to form aldehydes richer by one carbon atom is known as hydroformylation or oxation. Compounds of transition metals from Group VIII of the Periodic Table of the Elements are often used as catalysts in these reactions. Well-known ligands include compounds from the classes of phosphines, phosphites, and phosphonites, each containing trivalent phosphorus P III< . A good overview of the current state of olefin hydroformylation can be found in R. Franke, D. Selent, A. Börner, "Applied Hydroformylation," Chem. Rev., 2012 (112), 11, 5675-5732, DOI:10.1021 / cr3001803.

[0004] EP 4 074 720 A1 describes a mixture of bisphosphites with one open and one closed wing unit. The bisphosphites are used as catalysts in hydroformylation.

[0005] The technical object of the invention is to provide a compound with which an increased yield of aldehyde can be achieved in the hydroformylation of olefins.

[0006] The object is achieved by a connection according to claim 1.

[0007] Compound according to formula ( I ): where R 1< , R 2< , R 3< , R 4< represent -(C 1 -C 12 )-alkyl.

[0008] In one embodiment, R 1< is - ter t< Bu.

[0009] In one embodiment, R 2< is - tert< Bu.

[0010] In one embodiment, R 3< is - tert< Bu.

[0011] In one embodiment, R 4< is - tert< Bu.

[0012] In one embodiment, the compound has the structure (2):

[0013] In addition to the compound itself, a method is also claimed in which the compounds described above are used.

[0014] Procedure comprising the following steps: a) Initially charging an olefin; b) adding a previously described compound; c) adding a Rh compound; d) supplying H 2 and CO; e) heating the reaction mixture from a) to d), whereby the olefin is converted to an aldehyde.

[0015] In a variant of the process, the Rh compound is selected from: Rh(acac)(CO) 2 , [(acac)Rh(COD)] (Umicore, acac = acetylacetonate anion; COD = 1,5-cyclooctadiene), Rh 4 CO 12 .

[0016] In a variant of the process, the Rh compound is Rh(acac)(COD).

[0017] In a variant of the process, H 2 and CO are added in process step d) at a pressure in the range of 1 to 6 MPa (10 to 60 bar).

[0018] In a variant of the process, H 2 and CO are added in process step d) at a pressure in the range of 1.5 to 4.5 MPa (15 to 45 bar).

[0019] In a variant of the process, the reaction mixture is heated in process step e) to a temperature in the range from 80 °C to 160 °C.

[0020] In a variant of the process, the reaction mixture is heated in process step e) to a temperature in the range from 100 °C to 140 °C.

[0021] In the following, the invention will be explained in more detail using exemplary embodiments. Synthese ( 1 ): 4,8-Di-tert-butyl-6-((3,3'-di-tert-butyl-2'-((dicyclohexylphosphanyl)oxy)-5,5'-dimethoxy-[1,1'-biphenyl]-2-yl)oxy)-2,10-dimethoxydibenzo[d,f][1,3,2]dioxaphosphepin

[0022]

[0023] A 0.533 M solution of n-butyllithium (1.7 ml; 0.906 mmol) in hexane is added dropwise to a solution of 3,3'-di-tert-butyl-2'-((4,8-di-tert-butyl-2,10-dimethoxydibenzo [d,f][1,3,2]dioxaphosphepin-6-yl)oxy)-5,5'-dimethoxy-[1,1'-biphenyl]-2-ol (0.6749 g; 0.906 mmol) in THF (9 ml) at -20 °C. The mixture is stirred for 20 min at this temperature, allowed to warm to 0 °C and a solution of chlorodicyclohexylphosphine (0.2214 g; 0.9513 mmol) in THF (4 ml) is added dropwise. The mixture is then allowed to warm to room temperature, stirred overnight, and the solvent is removed in vacuo. The residue is taken up in toluene (9 ml), the resulting mixture is filtered, and the filtrate is concentrated in vacuo and dried for 2 h at 50°C / 0.1 mbar. The resulting residue is crystallized from hot acetonitrile (8 ml). Filtration and drying in vacuo yield 0.630 g (0.670 mmol, 74%).

[0024] Elemental analysis (calculated for C 56 X 78 O 8 P 2 = 941.18 g / mol): C = 71.35 (71.47); H = 8.40 (8.35); P = 6.42 (6.58)%.

[0025] ESI-TOF HRMS: m / z= 941.5244; [M++H], calculated m / z= 941.5250. Synthese ( 2 ): 2,4,8,10-Tetra-tert-butyl-6-((3,3',5,5'-tetra-tert-butyl-2'-((dicyclohexylphosphanyl)oxy)-[1,1'-biphenyl]-2-yl)oxy)dibenzo[d,f][1,3,21dioxaphosphepin

[0026]

[0027] A 0.533 M solution of n-butyllithium (1.14 ml; 0.6054 mmol) in hexane is added dropwise to a solution of 3,3',5,5'-tetra-tert-butyl-2'-((2,4,8,10-tetra-tert-butyldibenzo [d,f][1,3,2]dioxaphosphepin-6-yl)oxy)-[1,1'-biphenyl]-2-ol (0.4897 g; 0.5766 mmol) in THF (5 ml) at -20 °C. The mixture is stirred for 20 min at this temperature, allowed to warm to 0 °C, and a solution of chlorodicyclohexylphosphine (0.1436 g; 0.6170 mmol) in THF (3 ml) is added dropwise. The mixture is then allowed to warm to room temperature, stirred overnight, and the solvent is removed in vacuo. The residue is taken up in toluene (9 ml), the resulting mixture is filtered, and the filtrate is concentrated in vacuo and dried for 2 h at 50°C / 0.1 mbar. The residue is dissolved in THF (3.5 ml). The solid that separates after the addition of acetonitrile (approx. 5 ml) is filtered, washed with a little acetonitrile, and dried. Yield: 0.272 g (0.260 mmol, 45%).

[0028] Elemental analysis (calculated for C 68 H 102 O 4 P 2 = 1045.50 g / mol): C = 78.23 (78.12); H = 9.74 (9.83); P = 5.71 (5.93)%.

[0029] ESI-TOF HRMS: m / z=1045.7322; [M++H], calculated m / z=1045.7332. synthesis (3) : ((3,3',5,5'-Tetra-tert-butyl-[1,1'-biphenyl]-2,2'-diyl)bis(oxy))bis(dicyclohexylphosphane)

[0030]

[0031] A 0.533 M solution of n-butyllithium (6.56 ml; 3.494 mmol) in hexane was added dropwise to a solution of 3,3',5,5'-tetra-tert-butyl-[1,1'-biphenyl]-2,2'-diol (0.6832 g; 1.6638 mmol) in THF (12 ml) at -20 °C. The mixture was stirred at this temperature for 20 min, allowed to warm to 0 °C, and a solution of chlorodicyclohexylphosphine (0.8287 g; 3.5606 mmol) in THF (6 ml) was added dropwise. The mixture was then allowed to warm to room temperature, stirred overnight, and the solvent was removed in vacuo. The residue was taken up in toluene (20 ml), the resulting mixture was filtered, the filtrate was concentrated in vacuo, and dried for 2 h at 50°C / 0.1 mbar. The residue was dissolved in THF (6 ml). The solid that separated after the addition of acetonitrile (4 ml) was filtered and dried. Yield: 0.469 g (0.582 mmol, 35%).

[0032] ESI-TOF HRMS: m / z=803.6021; [M++H]; calculates m / z=803.6025. Catalysis experiments

[0033] The hydroformylation was carried out in a 200 ml autoclave from Premex Reactor AG, Lengau, Switzerland, equipped with pressure control, gas flow measurement, a gassing stirrer, and a pressure pipette. To minimize the influence of moisture and oxygen, the toluene used as solvent was purified in a Pure Solv. MD-7 system and stored under argon. The olefin cis / trans-2-pentene (Aldrich) used as substrate was heated to reflux over sodium and distilled under argon. Solutions of the catalyst precursor and the ligand, each in toluene, were mixed in the autoclave under an argon atmosphere. [(acac)Rh(COD)] (Umicore, acac = acetylacetonate anion; COD = 1,5-cyclooctadiene) was used as the catalyst precursor. The autoclave was heated to 12 bar to a final pressure of 20 bar while stirring (1500 rpm). After reaching the reaction temperature, the olefin was forced into the autoclave at an overpressure set in the pressure pipette.The reaction was conducted at constant pressure (20 bar) (pressure regulator from Bronkhorst, NL) for 4 hours. After the reaction time, the autoclave was cooled to room temperature, depressurized while stirring, and purged with argon. 1 ml of the reaction mixture was removed immediately after the stirrer was switched off, diluted with 10 ml of pentane, and analyzed by gas chromatography: HP 5890 Series II plus, PONA, 50 mL x 0.2 mm x 0.5 µm.

[0034] The experiment was carried out with the compounds (1), (2) and (3) carried out.

[0035] The connections (2) and (3) serves as a reference ligand. Results of the catalysis experiments

[0036] [Rh]: 100 ppm, p: 20 bar, T: 120 °C; t: 4 h; Rh:L = 1:2 Table: Hydroformylation of cis / trans-2-pentene ligand Aldehyde yield [%] (1) 94 (2)* 99 (3) < 1 * compound according to the invention

[0037] The tests carried out prove that the task is solved by a compound according to the invention.

Claims

1. Compound of formula (I): where R1, R2, R3, R4 are - (C1-C12) -aryl.

2. Compound according to Claim 1, wherein R1 is -tertBu.

3. Compound according to either of Claims 1 and 2, wherein R2 is -tertBu.

4. Compound according to any of Claims 1 to 3, wherein R3 is -tertBu.

5. Compound according to any of Claims 1 to 4, wherein R4 is -tertBu.

6. Compound according to any of Claims 1 to 5, wherein the compound has the structure (2):

7. Process comprising the process steps of: a) initially charging an olefin; b) adding a compound according to any of Claims 1 to 6; c) adding a Rh compound; d) feeding in H2 and CO; e) heating the reaction mixture from a) to d), to convert the olefin to an aldehyde.

8. Process according to Claim 7, wherein the Rh compound is selected from: Rh(acac) (CO)2, [(acac) Rh(COD)] (Umicore, acac = acetylacetonate anion, COD = 1,5-cyclooctadiene), Rh4CO12.

9. Process according to either of Claims 7 and 8, wherein the Rh compound is Rh(acac) (COD).