Bisphosphites with tert-butyl radicals on the central unit and substituted outer unit

Abstract

The central unit is a bisphosphite having a tertiary butyl group and a substituted external unit.

Description

[Technical Field]

[0001] This invention relates to bisphosphites having a tertiary butyl group as the central unit and having substituted external units. Furthermore, this invention relates to the use of bisphosphites in hydromethionization reactions. [Previous Technology]

[0002] Phosphorus compounds play a key role in a variety of reactions, such as in hydrogenation, hydrocyanation and hydromethionization as ligands.

[0003] WO 02 / 00670 A1 discloses bisphosphite compounds, their metal complexes, and the use of these compounds and complexes in the hydromethionization of alkenes. The disclosure specifically includes compound (IIa): [Summary of the Invention]

[0004] The technical objective of this invention is to provide a compound that can achieve excellent yields in the hydromethionization reaction of olefins.

[0005] This objective is achieved by using the compound of claim 1.

[0006] Compound of formula (I): wherein R1, R2, R3, R4, and R5 are selected from: -H, -(C1-C4)-alkyl, -O-(C1-C4)-alkyl, and at least one of the groups R1, R2, R3, R4, and R5 is not -H.

[0007] In one embodiment, R1, R2, R3, R4, and R5 are selected from: -H, -CH3, -CH2-CH3, -tert-butyl, and -O-CH3.

[0008] In one embodiment, at least two of the groups R1, R2, R3, R4, and R5 are -H.

[0009] In one embodiment, at least three of the groups R1, R2, R3, R4, and R5 are -H.

[0010] In one embodiment, R1, R2, R3, R4, and R5 are selected from -H and -CH3.

[0011] In one embodiment, R1, R2, R3, R4, and R5 are selected from -H, -CH2-CH3.

[0012] In one embodiment, R1, R2, R3, R4, and R5 are selected from: -H, -tert-butyl.

[0013] In one embodiment, R1, R2, R3, R4, and R5 are selected from: -H, -O-CH3.

[0014] In one embodiment, the compound has one of the structures (1) to (3):

[0015] In one embodiment, the compound has one of the structures (4) to (6):

[0016] In one embodiment, the compound has one of the structures (7) to (9):

[0017] In one embodiment, the compound has one of the structures (10) or (11):

[0018] In one embodiment, the compound has structure (12): .

[0019] In one embodiment, the compound has structure (1): .

[0020] In one embodiment, the compound has structure (2): .

[0021] In one embodiment, the compound has structure (3):

[0022] In one embodiment, the compound has structure (4):

[0023] In one embodiment, the compound has structure (5):

[0024] In one embodiment, the compound has structure (6):

[0025] In one embodiment, the compound has structure (7):

[0026] In one embodiment, the compound has structure (8): .

[0027] In one embodiment, the compound has structure (9):

[0028] In one embodiment, the compound has the structure (10):

[0029] In one embodiment, the compound has the structure (11): .

[0030] In addition to the compound itself, a method is also requested in which the above-described compound is used.

[0031] The method comprises the following steps: a) initially introducing an olefin; b) adding the compound described above; c) adding a substance containing Rh; d) feeding H2 and CO; e) heating the reaction mixture from a) to d) to convert the olefin into an aldehyde.

[0032] In a variant of the method, the substance containing Rh is selected from: Rh(acac)(CO)2, Rh(acac)(cod)(Umicore, acac = acetyl acetone anion; cod = 1,5-cyclooctadiene), Rh4CO12.

[0033] In a variation of the method, the substance containing Rh is Rh(acac)(CO)2.

[0034] The invention will now be described in more detail with reference to exemplary embodiments.

Implementation Method

[0035] In the first stage of synthesis, 0.076 mol of naphthalene-1,8-diol was dried overnight at 50°C under vacuum using an oil pump. The next day, a Schlenk flask was filled with argon and naphthalene-1,8-diol was dissolved in 350 ml of dry toluene. In a Schlenk flask that had been repeatedly evacuated and filled with inert gas, 0.114 mol of phosphorus trichloride was dissolved in 120 ml of dry toluene. Next, the naphthalene-1,8-diol solution was slowly and steadily added dropwise to a PCl3 solution at -20°C. Subsequently, 0.165 mol of triethylamine was slowly added dropwise to the solution at -20°C with high stirring. The solution was allowed to reach room temperature and stirred continuously overnight. The next day, the reaction mixture was filtered using a sintered glass filter, the filter cake was washed twice with 25 ml of toluene each time, and the filtrate was concentrated under vacuum at 40°C using an oil pump. Yield: 86% Second Stage

[0036] Weigh 0.016 mol of biphenyl, dry it under vacuum overnight using an oil pump, and then fill it with argon the next morning. Dissolve the biphenyl in 40 ml of toluene. Under an inert atmosphere, weigh 0.016 mol of phosphite, dissolve it in 40 ml of toluene, and mix it with 0.016 mol of degassed triethylamine. Over a period of 1 h, add the phosphite-toluene solution dropwise to the biphenyl solution at room temperature and stir at 40°C for 24 h. Filter the reaction mixture using a sintered glass frit filter and wash the filter cake twice with 20 ml of toluene each time. Concentrate the obtained filtrate under vacuum using an oil pump at 40°C and dry it. Yield: 75% Third Stage

[0037] Under an inert atmosphere, 11.9 mmol of monophosphite was weighed and dissolved in 150 ml of dry toluene and 29.8 mmol of degassed triethylamine. In a Schlenk flask that had been repeatedly evacuated and filled with inert gas, 14.9 mmol of phosphorus trichloride was dissolved in 100 ml of dry toluene and cooled to 0°C. The organochlorine phosphite-triethylamine solution was then added to the phosphorus trichloride solution at 0°C. The reaction mixture was stirred at room temperature for 24 h. The formed ammonium chloride was filtered off using sintered glass and washed twice with 50 ml of dry toluene each time. The filtrate was then concentrated to dryness under vacuum at 45°C using an oil pump. Yield: 87% Synthesis (1)

[0038] Under an inert atmosphere, 2.9 mmol of organic dichlorophosphite was weighed and suspended in 30 ml of dry toluene. 6.7 mmol of phenol was weighed into a Schlenk flask and rapidly evacuated and filled with inert gas using an oil pump. Next, the Schlenk flask was filled with argon, and the phenol was dissolved in 20 ml of dry toluene, along with 14.3 mmol of degassed triethylamine. Then, the phenol solution was slowly and steadily added to the dichlorophosphite suspension at room temperature. The reaction solution was stirred overnight at room temperature. The formed ammonium chloride was filtered off using a sintered glass filter, and the solution was washed twice with 10 ml of dry toluene each time. The resulting filtrate was then concentrated to dryness under vacuum at 40°C using an oil pump. The dried filtrate was purified by column chromatography. Yield: 60%

[0039] Compounds (2) to (12) and comparative compound (IIa) were prepared by a similar method. Catalytic experiments

[0040] Argon atmosphere was used. The reaction vessel was pre-dried at high temperature (80°C) under vacuum with an oil pump. The liquid was bubbled in argon for at least 15 minutes to degas the liquid. Hydromethoxylation was carried out in a 0.5 liter high-pressure vessel from Berghof Products + Instruments GmbH equipped with a constant pressure device. The reactor was heated with an oil bath from IKA. The reactor was used for gas exchange and as a temperature control unit. Five glass vials (20 ml) containing the catalyst solution and a magnetic stir bar, pressed together under argon, were placed in the reactor to allow gas exchange between the vials and the reactor space. The temperature of the glass vials was controlled by the heat transfer oil present in the reactor. The stated reaction temperature was measured inside the glass vials. The substance used is n-octene (Oxeno GmbH, which contains a mixture of the following octene isomers: 1-octene: 3%; cis+trans-2-octene: 49%; cis+trans-3-octene: 29%; cis+trans-4-octene: 16%; structurally isomer of octene: 3%).

[0041] For the experimental setup, a stock solution was prepared in advance under an argon atmosphere. To this end, 0.0127 g of Rh(acac)(CO)₂ and the corresponding amount of phosphite compound (MV Lig:Rh = 5:1) were weighed and added to 48.0 ml of toluene. Approximately 8 ml of this solution was dispensed into each vial and weighed precisely. The vials were placed in the reactor and the reactor was shut off. The reactor was purged three times with argon and three times with syngas (Linde; H₂ (99.999%): CO (99.997%) = 1:1). After pressure testing, the autoclave was heated to the desired temperature of 120°C with stirring (900 rpm) at a total pressure of 10 bar. Once the reaction temperature was reached, the syngas pressure was increased to 20 bar and 2 ml of reactant was added metered in each step using an HPLC pump to initiate the reaction. This achieved an Rh concentration of 100 ppm. One hour after the reaction was initiated at a fixed pressure, samples were removed from each vial and analyzed by gas chromatography (HP 6890, Petrocol® DH 150, 150 m x 0.25 mm x 1 µm) undiluted. Residual olefins and aldehydes were quantitatively determined relative to toluene, used as an internal standard. The results listed in the table below are averages from a single experimental run. Results of the catalytic experiment.

[0042] [Rh]:100 ppm, p: 20 bar, T: 120℃; t: 1 h

[0043] The n-octene mixture used is composed of the following C8 isomers: 1-octene, cis-2-octene, trans-2-octene, cis-3-octene, trans-3-octene, cis-4-octene and trans-4-octene.

[0044] The experiments conducted demonstrate that the compound of the present invention achieves the stated objective.

Claims

1. A compound of formula (I), wherein R1, R2, R3, R4, and R5 are selected from: -H, -(C1-C4)-alkyl, -O-(C1-C4)-alkyl, and at least one of the groups R1, R2, R3, R4, and R5 is not -H.

2. The compound of claim 1, wherein R1, R2, R3, R4, and R5 are selected from: -H, -CH3, -CH2-CH3, -tert-butyl, and -O-CH3.

3. A compound of any one of claims 1 and 2, wherein at least three of the groups R1, R2, R3, R4, and R5 are -H.

4. The compound of claim 1 or 2, wherein R1, R2, R3, R4, and R5 are selected from -H and -CH3.

5. The compound of claim 1 or 2, wherein R1, R2, R3, R4, and R5 are selected from: -H, -CH2-CH3.

6. The compound of claim 1 or 2, wherein R1, R2, R3, R4, and R5 are selected from: -H, -tert-butyl.

7. The compound of claim 1 or 2, wherein R1, R2, R3, R4, and R5 are selected from: -H, -O-CH3.

8. The compound of claim 1, wherein the compound has one of the structures (1) to (3):

9. The compound of claim 1, wherein the compound has one of the structures (4) to (6):

10. The compound of claim 1, wherein the compound has one of the structures (7) to (9):

11. The compound of claim 1, wherein the compound has one of structures (10) and (11):

12. The compound of claim 1, wherein the compound has structure (12): .

13. A method for the hydromethionization of an olefin, comprising the following steps: a) initially introducing an olefin; b) adding a compound as claimed in any one of claims 1 to 12; c) adding a substance containing Rh, wherein the Rh-containing substance is selected from: Rh(acac)(CO)2, Rh(acac)(cod) (acac = acetylene anion; cod = 1,5-cyclooctadiene), Rh4CO12; d) feeding H2 and CO; e) heating the reaction mixture from a) to d) to convert the olefin into an aldehyde.

14. The method of claim 13, wherein the substance containing Rh is Rh(acac)(CO)2.