Diphosphites with substituents in the cis position

Abstract

Diphosphites with substituents in the cis position and use thereof in hydroformylation.

Claims

1. Compound of formula (I): ##STR00005## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 are selected from: (C.sub.1-C.sub.12)-alkyl, O(C.sub.1-C.sub.12)-alkyl, and R.sup.5 is selected from: (C.sub.1-C.sub.12)-alkyl, O(C.sub.1-C.sub.12)-alkyl, -Ph.

2. Compound according to claim 1, wherein R.sup.1 is selected from: CH.sub.3, OCH.sub.3, -.sup.tertBu.

3. Compound according to claim 1, wherein R.sup.1 is -.sup.tertBu.

4. Compound according to claim 1, wherein R.sup.2 is selected from: CH.sub.3, OCH.sub.3, -.sup.tertBu.

5. Compound according to claim 1, wherein R.sup.2 is -.sup.tertBu.

6. Compound according to claim 1, wherein R.sup.3 is selected from: CH.sub.3, OCH.sub.3, -.sup.tertBu.

7. Compound according to claim 1, wherein R.sup.3 is -.sup.tertBu.

8. Compound according to claim 1, wherein R.sup.4 is selected from: CH.sub.3, OCH.sub.3, -.sup.tertBu.

9. Compound according to claim 1, wherein R.sup.4 is -.sup.tertBu.

10. Compound according to claim 1, wherein R.sup.5 is selected from: CH.sub.3, OCH.sub.3, -.sup.tertBu, -Ph.

11. Compound according to claim 1, wherein R.sup.5 is -Ph.

12. Compound according to claim 1, wherein the compound has the structure (1): ##STR00006##

13. Process comprising the process steps of: a) initially charging an olefin; b) adding a compound according to claim 1; c) adding a Rh compound; d) feeding in H.sub.2 and CO; e) heating the reaction mixture from a) to d), to convert the olefin to an aldehyde.

14. Process according to claim 13, wherein the Rh compound is selected from: Rh(acac)(CO).sub.2, [(acac)Rh(COD)] (Umicore, acac=acetylacetonate anion; COD=1,5-cyclooctadiene), Rh.sub.4CO.sub.12.

15. Process according to claim 13, wherein the Rh compound is Rh(acac)(COD).

Description

[0033] The invention shall be elucidated in more detail hereinbelow with reference to a working example.

Synthesis (1): 2,4,8,10-Tetra-tert-butyl-6-((3,3,5,5-tetra-tert-butyl-2-((4S,5R)-4,5-diphenyl-1,3,2-dioxaphospholan-2-yl)oxy)-[1,1-biphenyl]-2-yl)oxy)dibenzo[d,f][1,3,2]dioxaphosphepine

[0034] ##STR00003##

[0035] 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 (0.430 g, 0.506 mmol) in THF (3 ml) were added dropwise at ?20? C. a solution of n-BuLi (0.532 M solution in hexane, 1.00 ml, 0.532 mmol). After 20 min the reaction solution was allowed to warm to 0? C. and to this was then added dropwise a solution of (4R,5S)-2-chloro-4,5-diphenyl-1,3,2-dioxaphospholane (0.148 g, 0.532 mmol) in THF (2 ml). After stirring overnight at room temperature, the solvent was removed under vacuum and toluene (6 ml) was added to the white residue and the undissolved constituents filtered off. The filtrate was again concentrated under vacuum and the crude product dried at 60? C. For purification, the latter was dissolved in acetonitrile (5 ml) at boiling point, after cooling the precipitate filtered off and the product isolated as a white solid (0.22 g, 0.202 mmol, 40% yield).

[0036] Elemental analysis (calculated for C.sub.70H.sub.92O.sub.6P.sub.2=1091.448 g/mol): C=77.22% (77.03%); H=8.45% (8.50%); P=5.68% (5.68%).

[0037] ESI-TOF HRMS: m/z=1090.6369

[0038] [M.sup.++H], calculated m/z=1091.6448 (found 1091.6442)

[0039] [M.sup.++Na], calculated m/z=1113.6262 (found 1113.6256)

Synthesis (2): 2,4,8,10-Tetra-tert-butyl-6-((3,3,5,5-tetra-tert-butyl-2-(((4R,5R)-4,5-diphenyl-1,3,2-dioxaphospholan-2-yl)oxy)-[1,1-biphenyl]-2-yl)oxy)dibenzo[d,f][1,3,2]dioxaphosphepine

[0040] ##STR00004##

[0041] 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 (0.474 g, 0.558 mmol) in THF (3 ml) were added dropwise at ?20? C. a solution of n-BuLi (0.533 M solution in hexane, 1.10 ml, 0.587 mmol).

[0042] After 20 min the reaction solution was allowed to warm to 0? C. and to this was then added dropwise a solution of (4R,5R)-2-chloro-4,5-diphenyl-1,3,2-dioxaphospholane (0.163 g, 0.587 mmol) in THF (3 ml). After stirring overnight at room temperature, the solvent was removed under vacuum and toluene (7 ml) added to the white residue and the undissolved constituents filtered off. The filtrate was again concentrated under vacuum and the crude product dried at 60? C. For purification, the latter was dissolved in acetonitrile at boiling point, after cooling the precipitate filtered off and the product isolated as a white solid (0.39 g, 0.357 mmol, 64% yield).

[0043] Elemental analysis (calculated for C.sub.70H.sub.92O.sub.6P.sub.2=1091.448 g/mol): C=77.22% (77.03%); H=8.57% (8.50%); P=5.50% (5.68%).

[0044] ESI-TOF HRMS: m/z=1090.6369

[0045] [M.sup.++H], calculated m/z=1091.6448 (found 1091.6449)

[0046] [M.sup.++Na], calculated m/z=1113.6262 (found 1113.6276)

Catalysis Experiments

[0047] The hydroformylation was conducted in a 200 ml autoclave from Premex Reactor AG, Lengau, Switzerland, equipped with pressure-retaining valve, gas flowmeter, sparging stirrer and 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 used as substrate (Aldrich) was heated at reflux over sodium and distilled under argon. Toluene solutions of the catalyst precursor and of the ligand were mixed in the autoclave under an argon atmosphere. Rh(acac)(COD) (Umicore, acac=acetylacetonate anion; COD=1,5-cyclooctadiene) was used as catalyst precursor. The autoclave was heated with stirring (1500 rpm) at 12 bar for a final pressure of 20 bar. After reaching the reaction temperature, the olefin was injected into the autoclave by way of a positive pressure established in the pressure pipette. The reaction was carried out at a constant pressure of 20 bar (closed-loop pressure controller from Bronkhorst, the Netherlands) over 4 h. At the end of the reaction time, the autoclave was cooled to room temperature, depressurized while stirring and purged with argon. 1 ml of reaction mixture was removed immediately after the stirrer had been switched off, diluted with 10 ml of pentane and analysed by gas chromatography: HP 5890 Series II plus, PONA, 50 m?0.2 mm?0.5 ?m.

[0048] The experiment was carried out with compounds (1) and (2).

[0049] The compound (2) serves here as reference ligand.

Results of the Catalysis Experiments

[0050] [Rh]: 100 ppm, p: 20 bar, T: 120? C.; t: 4 h; Rh:L=1:2

TABLE-US-00001 TABLE Hydroformylation of cis/trans-2-pentene Ligand n-selectivity [%] (1)* 83.6 (2) 74.1 *inventive compound

[0051] The experiments carried out demonstrate that the stated object is achieved by a compound according to the invention.