Butadiene telomerization catalyst precursor preparation

Abstract

Use a solvent blend that contains 1-methoxy-2,7-octadiene and an alkanols rather than the alkanols by itself to prepare a catalyst precursor suitable for use in butadiene telomerization.

Claims

1. A process for telomerizing butadiene, the process comprising: preparing a telomerization catalyst precursor used in telomerization of butadiene that comprises dissolving one equivalent of palladium acetyl acetonate and from one to three equivalents of a phosphine in a solvent blend that comprises methanol and 1-methoxy-2,7-octadiene at a temperature within a range of from 0 degrees centigrade to 100 degrees centigrade to yield a catalyst precursor solution that comprises an aryl phosphine-palladium octadienyl complex represented formulaically either as [(Ar.sub.nPR.sub.(3-n)).sub.xPdY] or as [(Ar.sub.nPR.sub.(3-n)).sub.xPdY].sup.+ wherein R is an alkyl or heteroatom-containing alkyl moiety with 1 to 12 carbon atoms, Ar is an aryl moiety or substituted aryl moiety, x=1 or 2, n=1, 2 or 3, and Y is a I-methoxy-2,7-octadiene ligand where no charge is present or octadienyl when a positive charge is present; and combining at least the telomerization catalyst precursor with butadiene to telomerize the butadiene.

2. The process of claim 1, wherein the conditions include a temperature within a range of from 5 degrees centigrade to 60 degrees centigrade.

3. The process of any of claims 1 through 2, wherein the number of equivalents of a phosphine is one or two.

4. The process of claim 1, wherein the solvent blend has a 1-methoxy-2,7-octadiene content within a range of from 0.1 weight percent to 50 weight percent, based upon total solvent blend weight.

5. The process of claim 4, wherein the solvent blend has a 1-methoxy-2,7-octadiene content within a range of from 10 weight percent to 25 weight percent, based upon total solvent blend weight.

6. The process of claim 1, wherein the catalyst precursor solution has a palladium concentration that ranges from 0.02 weight percent to 2 weight percent, as palladium metal, based on total catalyst precursor solution weight.

7. The process of claim 6 wherein the catalyst precursor solution has a palladium concentration that ranges from 0.1 weight percent to 1 weight percent, as palladium metal, based on total catalyst precursor solution weight.

8. The process of claim 1, wherein the telomerization catalyst precursor remains in solution for a period of at least 360 hours at a temperature within a range of from 5 C. to 60 C. and a palladium concentration exceeding 0.1 weight percent.

9. The process of claim 1, wherein the telomerization catalyst precursor does not include butadiene.

Description

GENERAL EXPERIMENTAL PROCEDURE

(1) In a general procedure for conducting the telomerization reaction, place di-n-butyl ether (GC internal standard)(Bu.sub.2O), methanol, methylcyclohexane (MeCy) solvent, a precatalyst stock solution prepared as detailed below (1 milliliter (mL)) and 0.5 mL of a 0.01932 molar solution of sodium methoxide (sometimes referred to as sodium methylate) (NaOMe) in methanol in a Fischer-Porter bottle. Unless otherwise specified, effect reactions with MeOH present at a 14 molar level, adjusting other components (also known as reagents) in the bottle to account for changes in reaction chemistry. Seal the bottle with a valve equipped with a septum port. Outside a glove box, distill approximately 5 mL of butadiene into a gas-tight syringe, determining the actual amount of butadiene in the syringe by weighing the syringe before and after injecting the butadiene into the bottle through the septum with the syringe needle placed below the surface of bottle contents. Place the butadiene-containing bottle in a preheated oil bath (40 C., 60 C. or 70 C. as shown below) equipped with a magnetic stirrer bar and allow the contents of the bottle to react for a select period of time (e.g. 4 hours). Sample bottle contents at 30 minutes, 1 hour, 2 hours and 4 hours after initiating reaction to develop a conversion versus time profile to determine whether there is an induction period or not. Use a 24 inch (61 cm) needle equipped with a gas-tight valve to draw the samples from the bottle for use in gas chromatography analysis.

Example (Ex) 1: Preparation of TCMPP Pre-Catalyst Stock Solution

(2) Using a glove box, dissolve 0.0147 gram (g) (0.0000483 mole) of palladium acetyl acetonate [(Pd(acac).sub.2], 0.0440 g (0.0000966 mole) of ligand, 0.134 g (0.00096 mole) of MOD-1, and 0.25 mL of a stock solution of acetic acid (AcOH) in methanol (0.1932 M) in approximately 24.75 mL methanol to a total volume of 25 mL and allow the resulting precatalyst stock solution to stir at ambient temperature (nominally 25 C.) for at least three days before use. Represent the ligand schematically as:

(3) ##STR00002##

Comparative Example (CEx) A

(4) Make a pre-catalyst stock solution as in Ex 1, but omit the MOD-1.

Ex 2

(5) Conduct a telomerization reaction at 40 C. using the pre-catalyst stock solution prepared in Ex 1. Show analytical results in Table 1 below.

(6) TABLE-US-00001 TABLE 1 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 43.2/44.1 97.3/97.2 42.0/42.9 1 hour 47.8/49 97.3/97.2 46.5/47.7 2 hours 53.2/54.5 97.3/97.5 51.7/53.1 4 hours 61.4/69.3 97.2/97.3 59.7/67.4

CEx B

(7) Replicate Ex 2 but with an aliquot of the pre-catalyst stock solution prepared in CEx A. Show analytical results in Table 2 below.

(8) TABLE-US-00002 TABLE 2 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 17.2 96.6 16.6 1 hour 22.9 97.0 22.2 2 hours 20.2 96.7 19.5 4 hours 26.9 96.8 26.0

CEx C

(9) Replicate Ex 1, but change the amount of MOD-1 from 10 equivalents to about 1200 equivalents per palladium and use one molar equivalent of TCMPP per molar equivalent of Pd(acac).sub.2.

CEx D

Replicate Ex 3, but Omit the MOD-1. lCEx E

(10) Conduct a telomerization reaction at 70 C. with an aliquot of the pre-catalyst solution prepared in CEx C. Show analytical results in Table 3 below.

(11) TABLE-US-00003 TABLE 3 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 30.9 92.1 28.4 1 hour 48.9 96.6 47.2 2 hours 68.8 96.6 66.5 4 hours 69.8 96.5 67.4

CEx F

(12) Conduct a telomerization reaction at 70 C. with an aliquot of the pre-catalyst solution prepared in CEx D. Show analytical results in Table 4 below.

(13) TABLE-US-00004 TABLE 4 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 60.5/44.8 96.5/96.1 58.3/43.1 1 hour 65.9/44.6 96.3/96 63.4/42.8 2 hours 72.3/45.5 96.2/96 70.0/43.7 4 hours 77.5/44.9 96.2/96 74.6/43.1

(14) These comparative examples are included to demonstrate the conditions for which the MOD-1 modification of the precatalyst is ineffective. In these examples, the MOD-1-modified pre-catalyst is less efficient and converts less butadiene than the unmodified counter example. It is likely that there is a significant inhibition of MOD-1 within this regime of 1000+ equivalents of MOD-1 to palladium.

Ex 3

(15) Replicate Ex 1, but use the ligand 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane (TMPTPA) represented schematically below instead of TCMPP.

(16) ##STR00003##

(17) Prepare two pre-catalyst stock solutions from this solution:

Ex 3.1

(18) For the first pre-catalyst stock solution, take 5 mL of the 25 mL solution and add (0.0170 g, 0.000122 moles) of MOD-1 to provide a pre-catalyst stock solution.

Ex 3.2

(19) For the second pre-catalyst stock solution, use aliquots of the stock solution of Ex 3 as prepared.

Ex 4

(20) Conduct a telomerization reaction at 40 C. using an aliquot of the pre-catalyst stock solution prepared in Ex 5.1. Show analytical results in Table 5 below.

(21) TABLE-US-00005 TABLE 5 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 13.4 93.6 12.5 1 hour 33.1 95.5 31.6 2 hours 45.1 95.3 42.9 4 hours 56.9 95.1 54.1

CEx G

(22) Replicate Ex 4, but use an aliquot of the pre-catalyst stock solution of Ex 3.2. Show analytical results in Table 6 below.

(23) TABLE-US-00006 TABLE 6 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 1.9 61.6 1.2 1 hour 2.0 65.8 1.3 2 hours 4.8 84.1 4.0 4 hours 44.0 95.2 41.9

Ex 5

(24) Use the pre-catalyst stock solution from Ex 3.1 but change the general procedure to include 1.0 mL of the sodium methoxide stock solution and 12 mL of methanol. Run the telomerization reaction at 40 C. Show analytical results in Table 7 below.

(25) TABLE-US-00007 TABLE 7 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 41.1 96.0 39.5 1 hour 51.5 95.7 49.2 2 hours 65.1 95.3 62.0 4 hours 76.7 95.1 72.9

CEx H

(26) Replicate Ex 5 but use the pre-catalyst stock solution from Ex 3.2. Show analytical results in Table 8 below.

(27) TABLE-US-00008 TABLE 8 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 3.1 76.3 2.4 1 hour 7.3 88.2 6.4 2 hours 9.6 90.3 8.7 4 hours 65.3 95.1 62.1

Ex 6

(28) Replicate Ex 1, but use the ligand TMPTPA at half the molar concentration of ligand.

CEx I

(29) Replicate Ex 6 but without the addition of MOD-1.

Ex 7

(30) Conduct a telomerization reaction at 40 C. using an aliquot from the pre-catalyst stock solution from Ex 6. Show analytical results in Table 9 below.

(31) TABLE-US-00009 TABLE 9 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 64.1 94.7 60.7 1 hour 77.9 95.2 74.9 2 hours 84.1 95.1 80.0 4 hours 90.0 95.0 85.5

CEx J

(32) Conduct a telomerization reaction at 40 C. with an aliquot of the pre-catalyst solution from CEx I. Show analytical results in Table 10 below.

(33) TABLE-US-00010 TABLE 10 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 33.6 92.9 31.2 1 hour 54.3 94.6 51.4 2 hours 71.0 95.0 67.4 4 hours 81.3 94.7 77.0

Ex 8

(34) Replicate Ex 1, but change the ligand to 1,3,5,7-tetramethyl-6-(2-methoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane (TMPTPA-OMe), represented schematically below, change the amount of equivalents of MOD-1 to 10, and reduce the molar equivalents of TMPTPA-OMe to half (one equivalent per Pd):

(35) ##STR00004##

CEx K

(36) Replicate Ex 8, but omit the MOD-1.

Ex 9

(37) Conduct at telomerization reaction at 40 C. with an aliquot of the pre-catalyst solution prepared in Ex 8. Show analytical results in Table 11 below.

(38) TABLE-US-00011 TABLE 11 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 15.2 95.1 14.5 1 hour 36.3 96.4 35.0 2 hours 63.6 96.7 61.5 4 hours 81.2 96.7 78.5

CEx L

(39) Conduct a telomerization reaction at 40 C. with an aliquot of the pre-catalyst solution prepared in CEx K. Show analytical results in Table 12 below.

(40) TABLE-US-00012 TABLE 12 Butadiene MOD-1 MOD-1 Time Conversion (%) Selectivity (%) Yield (%) 30 min 1.5 74.0 1.1 1 hour 4.6 89.9 4.1 2 hours 18.2 95.4 17.4 4 hours 50.7 96.5 48.9

Ex 10

(41) Conduct at telomerization reaction at 70 C. with an aliquot of the pre-catalyst solution prepared in Ex 8. Show analytical results in Table 13 below.

(42) TABLE-US-00013 TABLE 13 Butadiene Conversion MOD-1 MOD-1 Time (%) Selectivity (%) Yield (%) 30 min 70.9 94.9 67.3 1 hour 83.4 95.0 79.2 2 hours 90.2 94.9 85.6 4 hours 93.0 94.9 88.3

CEx M

(43) Conduct a telomerization reaction at 70 C. with an aliquot of the pre-catalyst solution prepared in CEx K. Show analytical results in Table 14 below.

(44) TABLE-US-00014 TABLE 14 Butadiene Conversion MOD-1 MOD-1 Time (%) Selectivity (%) Yield (%) 30 min 55.5 94.5 52.4 1 hour 73.6 94.5 69.6 2 hours 89.0 94.5 84.1 4 hours 95.3 94.5 90.1

(45) Several points of note emerge from a review of the above examples and comparative examples. First, addition of MOD-1 to methanol to create a solvent blend results in at least a substantial decrease in duration and in some cases elimination of an induction period before the catalyst precursor is ready to take an active part in telomerization. Second, use of a solvent blend (methanol and MOD-1) in preparation of telomerization catalyst precursor results in an increase in overall conversion of butadiene at a reaction temperature below 70 C. relative to conversion obtained with a telomerization catalyst precursor prepared in the absence of MOD-1 (methanol only) of at least 10%. Third, the telomerization catalyst precursor is stable in that it does not form solids that precipitate out of solution under the conditions stated in the examples (Ex 1-12) whereas under the same conditions save for use of methanol rather than a blend of methanol and MOD-1, a visually discernible amount of telomerization catalyst precursor effectively precipitates out of solution. The enhanced stability of the inventive telomerization catalyst precursor has an economic benefit in that one may decrease the amount of ligand used in its preparation.

Ex 11

Preparation of MOD-1 Modified Catalysts

(46) Use a 1 gallon laboratory reactor to prepare the pre-catalyst solution. Operate the reactor with a reactor jacket set point temperature of 35 C., and a methanol condenser set point temperature of 5 C. Load the reactor with 53.9 g TCMPP and 17.9 g Pd(acac).sub.2, and then purge the reactor with N.sub.2 at 0.5 scfh (14.2 liters/hour). Load the solvent reservoir with 1480.5 g methanol and sparge the reservoir with N.sub.2. Transfer 419 g methanol to the reactor at 18 mL/min over 30 min. Start agitation of reactor contents at 580 rpm. Transfer an additional 838 g of methanol to the reactor at 152 mL/min over 7 min Add aqueous acetic acid solution (3.71 g acetic acid+1.59 g water) to the reactor with continued agitation. Add remaining methanol (223.5 g) to the reactor at 151 mL/min over 6 min, followed by 493.5 g of MOD-1. Reduce the reactor N.sub.2 purge rate to 0.15-0.25 scfh (4.3-7.1 liters/hour). The overall pre-catalyst composition is designated as: Pd/TCMPP/acetic acid molar ratio of 1.00/2.01/1.04 and palladium concentration of 0.31 wt %. Allow the pre-catalyst solution to stir at 35 C. over 22 days at 580 rpm, sampling the pre-catalyst solution on days 1, 8, 15 and 22 for telomerization activity evaluation. Visual observation shows no evidence of solids precipitation over a period of 578 hours.

(47) Take samples of the reactor contents on Day 1 using Pressure-Lok gas-tight syringes, and transfer the samples to a glove box maintained at less than 1 ppm oxygen. Periodically determine composition of such samples by P.sup.31 NMR spectroscopy (400 megahertz (MHz) at 40 C. over an acquisition time of two to four hours, adding approximately 10% of D.sub.4-methanol as a lock solvent). Control reactor content temperature either by a heated solvent bath, or by the glove box air-conditioner. Periodically take temperature measurements over the timescale of the reactions to confirm that temperature is controlled to 1 C. In some cases, add an internal standard, triphenylphosphine oxide, so that absolute concentrations can be determined. See Table 15 below for P.sup.31 NMR composition data.

(48) TABLE-US-00015 TABLE 15 Mole fraction of phosphorus by species* Initial MOD-1 Other Time TCMPP Phospho- Pre- Modified Uniden- (hrs) TCMPP Oxide nium catalyst Catalyst tified 0 0.02 0.04 0.00 0.91 0.00 0.03 16 0.01 0.04 0.02 0.77 0.15 0.01 23 0.02 0.03 0.05 0.66 0.24 0.00 49 0.00 0.06 0.13 0.12 0.68 0.00 64 0.00 0.03 0.16 0.00 0.82 0.00 333 0.00 0.07 0.13 0.00 0.77 0.03 *TCMPP if free ligand, TCMPP Oxide is the phosphine oxide, Phosphonium is [(2-OMe, 5-ClC.sub.6H.sub.3).sub.3P(CH.sub.2CHCHCH.sub.2CH.sub.2CH.sub.2CHCH.sub.2)].sup.+, Initial precatalyst is {(2-OMe, 5-ClC.sub.6H.sub.3).sub.3P}.sub.2Pd(acetyl acetoante)].sup.+, MOD-1 modified catalyst is [(Ar.sub.nPR.sub.(3n)).sub.xPdY],

(49) This Ex 11 (with MOD-1 addition) shows that the initial pre-catalyst is converted to a MOD-1 modified catalyst over about 70 hours, after which no further significant changes occur. There is no discernible evidence showing formation of [Pd(TCMPP).sub.2(CH.sub.2C{(CO)Me}.sub.2].

(50) Table 16 below shows the catalyst activity and selectivity of the MOD-1 modified catalyst compared with the performance of the control catalyst that was not treated with MOD-1.

(51) TABLE-US-00016 TABLE 16 Butadiene Conversion (%) Control: No MOD-1 Butadiene Conversion (%) after Catalyst Pre-treatment Aging with MOD-1 for Reaction Time on Day 1 1 Day 8 Days 15 Days 22 Days 12-15 min 3.3 20.1 58.2 65.5 66.3 45 min 24.5 52.0 67.0 74.5 72.7 80-90 min 50.8 67.7 73.7 77.2 80.2 130-150 min 67.9 79.9 81.6 83.4 82.0 220-240 min 76.9 84.3 85.6 86.7 84.8 Final MOD-1 96.4 95.8 93.3 96.6 96.3 Selectivity (%)

(52) This data shows that the pre-catalyst is converted to a new, stable complex, [(Ar.sub.nPR.sub.(3-n)).sub.xPdY], which exhibits improved activity at 60 C. in telomerization, with a decrease in an induction period.

CEx K-O: Solids Precipitation from Unmodified Pre-Catalyst Solutions

(53) Replicate Ex 11 with changes in palladium complex as shown in Table 17 below and elimination of MOD-1. A visual examination of catalyst solutions shows that solids ([Pd(TCMPP).sub.2(CH.sub.2C{(CO)Me}.sub.2) begin to precipitate out of solution at 338 hours in the 1 gallon reactor at 20 C. with an initial palladium concentration of approximately 0.31 weight percent. At a smaller scale in the glove box under otherwise similar conditions, precipitation out of solution begins at approximately 310 hours (CEx L). Table 17 below shows precipitation times of catalyst that have not been modified by MOD-1 addition.

(54) TABLE-US-00017 TABLE 17 Initial Palladium Time of first Concentration evidence of Concentration of Temperature (Weight % as precipitation [Pd(TCMPP).sub.2(CH.sub.2C{(CO)Me}.sub.2] Experiment ( C.) Pd) (hrs) at time of precipitation(Weight %) CEx K 31 0.305 76 0.79 CEx L 30 0.305 115 0.57 CEx M 20 0.305 310 0.68 CEx N 31 0.153 82 0.70 CEx O 31 0.102 120 0.64

(55) CEx K-O show that, absent modification with MOD-1, solids precipitation occurs, such that the initially formed pre-catalyst is converted to a new, largely insoluble species, [Pd(TCMPP).sub.2(CH.sub.2C{(CO)Me}.sub.2]. The insoluble species can, in turn, foul process equipment.

CEx P

(56) Add 2 wt % of isolated, solid [Pd(TCMPP).sub.2(CH.sub.2C{(CO)Me}.sub.2] to a freshly prepared pre-catalyst solution and stir for half an hour in a glove box to allow dissolution of the solid and to achieve solid-liquid equilibrium Immediate P.sup.31 NMR analysis shows a palladium (0) complex concentration in solution at room temperature (nominally 20 C.) of 0.08 wt %.

Ex 12

(57) In a glovebox, dissolve degassed glacial acetic acid (AcOH) (55.3 L) in degassed MeOH to a volume of 5 mL (0.1932 M AcOH in MeOH) to form AcOH solution. Dissolve palladium(II) acetylacetonate (Pd(acac).sub.2) (0.0110 g, 0.0000362 moles), 2,3-(dihydrobenzofuran-7-yl)diphenylphosphine (DHBDPP, illustrated below) (0.0220 g, 0.0000724 moles) and 0.1875 mL of the AcOH solution in 15.0 mL MeOH and 3.6 mL MOD-1 to form a precatalyst stock solution. Allow the precatalyst solution to stir for 6 days at 25 C. before use.

(58) Add dibutyl ether (Bu.sub.2O, 5 mL), 12.8 M MeOH (10.96 mL), anhydrous degassed methylcyclohexane (MeCy, 1.6 mL), the precatalyst stock solution (1 mL), and a portion of a solution of sodium methoxide (NaOMe) (1.0 mL) in MeOH (0.01932 M) to a Fisher-Porter bottle. Seal the Fisher-Porter bottle with a valve equipped with a septum port.

(59) Use the above-noted General Experimental Procedure, a temperature of 40 C., a reaction time of 4 hours and sampling at 30 minutes, 60 minutes, 120 minutes and 240 minutes followed by GC analysis to evaluate performance of the MOD-1 modified pre-catalyst. See Table 18 below for a summary of such performance.

(60) ##STR00005##

CEx Q

(61) Replicate Ex 12, but eliminate the MOD-1 addition, and change the amounts of palladium(II) acetylacetonate (Pd(acac).sub.2) to 0.0980 g (0.00003217 mole), DHBDPP to 0.0196 g (0.00006441 mole) and AcOH solution to 0.167 mL AcOH in 16.5 mL MeOH.

Ex 13

(62) Replicate Ex 12, but change the oil bath temperature to 60 C.

CEx R

(63) Replicate CEx Q, but change the oil bath temperature to 60 C.

Ex 14

(64) Replicate Ex 12, but with the following changes: in making the precatalyst solution, use the following amounts: 0.0147 g (0.0000483 mole) of Pd(acac).sub.2, 0.250 mL of AcOH stock solution, 20 mL MeOH and 4.75 mL MOD-1; substitute triphenylphosphine (TPP, shown schematically below) (0.0253 g, 0.0000965 moles) for DHBDPP; allow the precatalyst to age for 7 days before use; and, in loading the Fisher-Porter bottle, use 0.5 mL of a solution of sodium methoxide in MeOH (0.01932 M) and 11.46 mL MeOH.

(65) ##STR00006##

CEx S

(66) Replicate Ex 1, but with the following changes: in making of the precatalyst solution, use the following amounts: 0.0147 g (0.0000483 miles) of Pd(acac).sub.2, 0.250 mL of AcOH stock solution and 24.75 mL MeOH. Substitute TPP (0.0253 g, 0.0000965 moles) for DHBDPP. In loading the Fisher-Porter bottle, use 0.5 mL of a solution of sodium methoxide in MeOH (0.01932 M) and 11.46 mL MeOH.

Ex 15

(67) Replicate Ex 14, but heat the oil bath 60 C.

CEx T

(68) Replicate CEx S, but heat the oil bath 60 C.

(69) TABLE-US-00018 TABLE 18 Final MOD-1 Butadiene Conversion (%) Selectivity Ex Ligand MOD-1 [MeOH] NaOMe:Pd L:Pd 30 min 1 hr 2 hr 4 hr (%) Ex 12 DHDDPP Yes 12.7 10:1 2:1 17.1 30.0 45.4 62.0 96.6 C DHDDPP N 12.7 10:1 2:1 7.1 19.0 37.7 60.4 96.6 Ex Q Ex 13 DHDDPP Yes 12.7 10:1 2:1 38.4 55.4 74.3 83.8 95.0 C DHDDPP N 12.7 10:1 2:1 17.4 36.7 65.3 83.4 95.2 Ex R Ex 14 TPP Yes 12.7 5:1 2:1 7.0 13.4 24.7 43.2 95.6 C TPP N 12.7 5:1 2:1 2.7 6.8 18.2 38.6 95.0 Ex S Ex 15 TPP Y 12.7 5:1 2:1 25.2 40.6 62.5 80.7 93.2 C TPP N 12.7 5:1 2:1 8.0 31.2 62.0 80.5 92.8 Ex T

(70) The data in Table 18 illustrate several points. First, the addition of MOD-1 to pre-catalyst solutions of DHDDPP and TPP generates catalytically competent complexes that result in a much faster initial rate of butadiene conversion than the pre-catalyst solutions that do not contain MOD-1 (compare the 30 min time points for all examples in Table 18). Second, the addition of MOD-1 to the pre-catalyst solutions of DHDDPP and TPP results in a higher overall conversion to products after the 4 hour reaction time. Third, the MOD-1 modification of the pre-catalyst does not affect the selectivity of the process. Thus, the modification of pre-catalyst solutions of DHDDPP and TPP with MOD-1 ultimately results in a higher yield of the desired product for all the demonstrated cases.