BUTADIENE TELOMERIZATION CATALYST AND PREPARATION THEREOF

Abstract

Catalyst compositions are prepared by contacting a palladium source and 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane and a methoxyocta-diene compound, in a primary aliphatic alcohol, under suitable conditions including a ratio of equivalents of palladium to equivalents of 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane ranging from greater than 1:1 to 1:1.3. The result is a complex of palladium, a 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaada-mantane ligand, and a ligand selected from a methoxyoctadiene ligand, an octadienyl ligand, or a protonated octadienyl. Such complexes may, in solution, exhibit surprising solubility and storage stability and are useful in the telomerization of butadiene, which is a step in the production of 1-octene.

Claims

1. A catalyst composition useful for catalyzing the telomerization of butadiene comprising a complex comprising palladium, a 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaada-mantane ligand, and a ligand selected from a methoxyoctadiene ligand, an octadienyl ligand, and a protonated octadienyl ligand.

2. The composition of claim 1 wherein the methoxyoctadiene ligand is selected from 1-methoxy-2,7-octadiene and 3-methoxy-1,7-octadiene.

3. The composition of claim 1 wherein the complex is dissolved in a primary aliphatic alcohol.

4. The composition of claim 3 wherein the primary aliphatic alcohol is selected from methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycerol, and combinations thereof.

5. The composition of claim 1 wherein the composition further comprises at least one of: (a) the counteranion of a carboxylic acid; (2) a promoter selected from alkoxides, enolates, phenoxides, borohydrides, and hydrazides, all of alkali metals; alkaline earth metals and quaternary ammoniums; alkali metal salts; and combinations thereof; and (3) combinations thereof.

6. A process for preparing a catalyst composition useful for catalyzing the telomerization of butadiene comprising dissolving as reagents a palladium source, 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane, and a methoxyoctadiene compound, in a primary aliphatic alcohol, such that the ratio of equivalents of the palladium to equivalents of the 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane ranges from greater than 1:1 to 1:1.3, under conditions sufficient to form a catalyst composition comprising a complex comprising palladium, a 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane ligand, and a ligand selected from a methoxyoctadiene ligand, an octadienyl ligand, or a protonated octadienyl ligand, in the primary aliphatic alcohol.

7. The process of claim 6 wherein (a) the palladium source is selected from palladium acetylacetonate, palladium formate, palladium acetate, palladium propionate, palladium octanoate, palladium carbonate, palladium hydroxide, palladium citrate, tetrakis(triphenylphosphine) palladium, bis(1,5-cyclooctadiene) palladium, bis(dibenzylideneacetone) palladium, and combinations thereof; (b) the methoxyoctadiene compound is selected from 1-methoxy-2,7-octadiene, 3-methoxy-1,7-octadiene, and combinations thereof; (c) the primary aliphatic alcohol is selected from methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycerol, and combinations thereof; or (d) a combination thereof.

8. The process of claim 6 wherein the process further comprises adding (a) a carboxylic acid; (b) a promoter selected from alkoxides, enolates, phenoxides, borohydrides, and hydrazides, all of alkali metals; alkaline earth metals and quaternary ammoniums; alkali metal salts; or a combination thereof; or (c) a combination thereof.

9. The process of claim 6 wherein the ratio of equivalents of the palladium source to the equivalents of the 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phospha-adamantane ranges from 1:1.2 to 1:1.3.

10. A process to telomerize butadiene comprising contacting butadiene and a catalyst composition comprising a complex comprising palladium, a 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane ligand, and a ligand selected from a methoxyoctadiene ligand, an octadienyl ligand, or a protonated octadienyl, under conditions sufficient to telomerize at least a portion of the butadiene.

Description

EXAMPLE 1

[0046] 1:1 Equivalents Ratio, Pd to TMTPA-di-OMe.

[0047] In the glovebox, dissolve 94 milliliters (mL) methanol (MeOH), 29 mL 1-methoxy-2,7-octadiene (MOD-1), and 91 microliters (4) acetic acid (AcOH) to prepare a stock solution that is 25 weight percent (wt %) MOD-1 and 75 wt % methanol.

[0048] Dissolve palladium(II) acetylacetonate (Pd(acac).sub.2) (0.0196 grams (g), 0.000064 moles (mol)), 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-di-OMe) (0.0227 g, 0.000064 mol), and 5 mL of the stock solution that is 25 wt % in MOD-1 described above to form an inventive catalyst solution. Allow the catalyst to stir for 3 days at 20 C. before use.

[0049] Add dibutyl ether (Bu.sub.2O, 5 mL) (GC standard), MeOH (13.35 mL), methylcyclohexane (MeCy, 1 mL) (a liquid fill that approximates conditions in a plant reactor), the catalyst (0.15 mL), and a portion of a solution of sodium methoxide (NaOMe) in MeOH (19.32 millimolar (mM), 0.5 mL) to a Fisher-Porter bottle. Seal the bottle with a valve equipped with a septum port. Distill butadiene (approximately 5 mL) into a gas-tight syringe, and determine the mass of butadiene by weighing the syringe before and after addition to the reactor. Inject the butadiene into the Fisher-Porter bottle with the needle placed below the surface of the solution. Place the reaction vessels into preheated oil baths. Remove 1 mL reaction aliquots at the 30 minute (min), 1 hour (h), 2 h, and 4 h time points through a 24 inch (24) needle equipped with a gas-tight valve, and subject each aliquot to gas chromatographic (GC) analysis.

[0050] Perform GC analyses on an AGILENT 7890 A chromatograph (AGILENT is a trademark of Agilent Technologies) using a DB-1701 column at constant gas flow. Use dibutyl ether as the internal standard, and determine response factors based on materials of known composition.

GC Method:

[0051] Column: LTM-DB-1701; Length: 30 meters (m); Diameter: 320 micrometers (m); Film thickness: 1.0 L; Mode: constant flow; Initial column flow: 1.27 milliliters per minute (mL/min).

[0052] Front inlet: Mode: split; Initial temp: 250 C.; Pressure: 6.7 pounds per square inch (psi); Split ratio: 50:1.

[0053] Detector: FID; Temp: 260 C.; H.sub.2 flow: 40 mL/min; Air flow: 400 mL/min; Make-up gas: He.

[0054] Oven: 250 C.

[0055] Low thermal mass (LTM) column: Initial temp: 50 C. and hold for 2 min; Ramp at 7.5 C./min. Total run time: 22 min.

[0056] Observe no solids precipitation of the catalyst composition after storing for more than 4 weeks.

EXAMPLE 2

[0057] After 2 weeks of storage of the catalyst composition of Example 1, conduct a telomerization reaction of butadiene using it, in duplicate, at 70 C. Conversion versus time is shown in Table 1.

TABLE-US-00001 TABLE 1 Telomerization reaction run in duplicate at 70 C. Pd:TMTPA-di-OMe = 1:1. Time Conversion of Selectivity MOD-1 Yield MOD-1 (min) butadiene (%) (%) (%) 30 49.2/54.8 94.3/94.0 46.4/51.5 60 68.0/72.5 94.6/94.4 64.3/68.4 120 84.6/86.0 94.8/94.6 80.2/81.4 240 91.8/90.0 94.8/94.5 87.0/85.0

EXAMPLE 3

[0058] 1:1.2 Equivalents Ratio, Pd to TMTPA-di-OMe.

[0059] Prepare the catalyst as in Example 1, but with 0.0273 g (0.000073 mol) TMTPA-di-OMe. Observe that the catalyst shows no solids precipitation after storing for more than 4 weeks.

EXAMPLE 4

[0060] After the 4 weeks catalyst storage, use the catalyst composition of Example 3 to conduct a telomerization reaction at 70 C. Conversion versus time is shown in Table 2.

TABLE-US-00002 TABLE 2 Telomerization reaction run in duplicate at 70 C. Pd:TMTPA-di-OMe = 1:1.2. Time Conversion of Selectivity MOD-1 Yield MOD-1 (min) butadiene (%) (%) (%) 30 62.6/55.6 93.5/94.0 58.5/52.3 60 72.1/66.0 93.7/94.1 67.6/62.1 120 83.6/79.2 93.8/94.2 78.4/74.6 240 87.7/83.2 93.9/94.2 82.4/78.4

EXAMPLE 5

[0061] 1:1.3 Equivalents Ratio, Pd to TMTPA-di-OMe.

[0062] Prepare another catalyst by dissolving Pd(acac).sub.2 (0.3200 g, 0.0011 mol), TMTPA-di-OMe (0.5000 g, 0.0014 mol), 70% acetic acid in water (0.6400 g, 0.0011 mol), MOD-1 (9.1100 g, 0.0650 mol) in MeOH (27.34 g, 34.5 mL). Stir this catalyst for more than 3 days. Dissolve 0.75 g of NaOMe in 300 mL MeOH to make a stock solution of NaOMe promoter. Conduct a telomerization reaction in a Parr reactor at 80 C. with 345 mL of MeOH, 198 g of crude C4 (49.4 wt % butadiene, with the remainder being primarily butanes and butenes), 8.4 mL of the NaOMe stock solution, 15.6 mL of heptane, 12.6 mL of a solution of diethylhydroxamic acid (DEHA) in MeOH (0.021 M), and 2.1 mL of the catalyst. Observe that the catalyst shows no solids precipitation after storing for more than 4 weeks.

EXAMPLE 6

[0063] Use the catalyst composition of Example 5 in a butadiene telomerization at 80 C.

[0064] Conversion of butadiene versus time is shown below in Table 3.

TABLE-US-00003 TABLE 3 Telomerization in a Parr reactor at 80 C. Pd:TMTPA-di-OMe = 1:1.3. Time Conversion of Selectivity MOD-1 Yield MOD-1 (min) butadiene (%) (%) (%) 5 36.1 90.9 32.8 30 62.3 92.4 57.6 60 82.0 92.3 75.7 90 90.1 92.5 83.3 120 93.4 92.5 86.4 150 95.2 92.5 88.1

EXAMPLE 7

[0065] 1:1.2 Equivalents Ratio, Pd to TMTPA-di-OMe.

[0066] Prepare the catalyst as in Example 1, but with 0.0768 g (0.00020 mol) TMTPA-di-OMe, 0.0510 g Pd(acac).sub.2 (0.00017 mol), 9.1 L acetic acid (0.00017 mol), 2.148 g 1-methoxy-2,7-octadiene, and 6.315 g methanol. Observe that the catalyst shows no solids precipitation after storing for more than 4 weeks at 40 C.

EXAMPLE 8

[0067] Use the catalyst of Example 7 for a telomerization reaction at 60 C. Conversion versus time is shown in Table 4.

TABLE-US-00004 TABLE 4 Telomerization reaction run in duplicate at 60 C. Pd:TMTPA-di-OMe = 1:1.2. Time Conversion of Selectivity MOD-1 Yield MOD-1 (min) butadiene (%) (%) (%) 30 45.7/37.6 96.0/95.7 43.9/36.0 60 57.1/58.0 95.5/95.6 54.5/55.4 120 69.5/74.6 95.4/95.4 66.3/71.2 240 80.7/84.0 95.3/95.3 76.9/80.1

Comparative Example A

[0068] 1:1.4 Equivalents Ratio, Pd to TMTPA-di-OMe.

[0069] Prepare the catalyst as in Example 1, but with 0.0307 g (0.000086 mol) TMTPA-di-OMe. After 1 week of catalyst storage, observe the precipitation of a white solid, showing that this equivalents ratio produces an unstable product.

Comparative Example B

[0070] 1:2 Equivalents Ratio, Pd to TMTPA-OMe.

[0071] Prepare a comparative catalyst using a different but similar oxaphosphaadamantane for the catalyst, i.e., 1,3,5,7-tetramethyl-6-(2-methoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-OMe), instead of the 1,3,5,7-tetra methyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-di-OMe) which is used to form the inventive catalyst. The TMTPA-OMe ligand may be represented schematically as structure (VI):

##STR00003##

[0072] To accomplish this, dissolve Pd(acac).sub.2 (0.7100 g, 0.0024 mol), TMTPA-OMe (1.5000 g, 0.0047 mol), 70% acetic acid in water (0.1410 g, 0.0024 mol), and MOD-1 (19.990 g, 0.1426 mol) in MeOH (60.000 g, 76.00 mL). Stir this catalyst solution for more than 3 days. Observe the precipitation of a white solid.

Comparative Example C

[0073] 1:1 Equivalents Ratio, Pd to TMTPA-OMe.

[0074] Prepare another comparative catalyst by dissolving Pd(acac).sub.2 (0.7100 g, 0.0024 mol), TMTPA-OMe (0.7500 g, 0.0024 mol), 70% acetic acid in water (0.1410 g, 0.0024 mol), and MOD-1 (19.990 g, 0.1426 mol) in MeOH (60.000 g, 76.00 mL). Stir this catalyst for more than 3 days. Observe the precipitation of a black solid.

Comparative Example D

[0075] 1:1.4 Equivalents Ratio, Pd to TMTPA-OMe.

[0076] In a glovebox, dissolve 94 mL methanol (MeOH), 29 mL 1-methoxy-2,7-octadiene (MOD-1), and 91 L acetic acid (AcOH) to prepare a stock solution that is 25 wt % MOD-1 and 75 wt % methanol.

[0077] Dissolve palladium(II) acetylacetonate (Pd(acac).sub.2) (0.0196 g, 0.000064 mol), 1,3,5,7-tetramethyl-6-(2-methoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-OMe) (0.0291 g, 0.000090 mol) and 5 mL of the stock solution that is 25 wt % in MOD-1, as described in Comparative Example C, to form a catalyst. Allow the catalyst to stir for 3 days at 20 C. Observe the precipitation of black solids.

Comparative Example E

[0078] 1:1.8 Equivalents Ratio, Pd to TMPTA-OMe.

[0079] Repeat the pre-catalyst preparation as described in Comparative Example D, but increase the amount of TMPTA-OMe (0.0374 g, 0.000118 mol). Observe the precipitation of white solids.

[0080] The above examples and comparative examples illustrate the improved storage stability of the inventive compositions in comparison with compositions comprising a complex having either a different but similar ligand (a 1,3,5,7-tetramethyl-6-(2-methoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-OMe) ligand instead of a 1,3,5,7-tetramethyl-6-(2,4-di-methoxphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMTPA-di-OMe) ligand, which differ from one another only in the presence or absence of a single methoxy group on the phenyl group), or in comparison with compositions comprising the same ligand but at a Pd to TMTPA-di-OMe equivalents ratio that is outside of the greater than 1:1 to 1:1.3 range that produces a storage-stable and more soluble product. In each of these comparisons, visibly discernible precipitate is encountered in the comparative's performance, either immediately or upon standing for a relatively short period of time, as specified, and therefore telomerization is not attempted therewith. In sharp contrast, telomerizations carried out using the inventive catalyst compositions are very successful.