This disclosure relates to metal complexes and to a process of preparing them.
Complexes of molybdenum and tungsten have been used as catalysts for certain chemical reactions, including olefin synthesis. They have the advantage of performing at least as well as ruthenium catalysts while being considerably cheaper (a function of the relative abundance of tungsten and molybdenum). A typical example of such a catalyst is the so-called Schrock catalyst, a typical example of which is shown below:
A more recent development is described in Angew. Chem. Int. Ed. 2011, 50,8829-7832, and in PCT published application WO 2012/116695. The metal complex has the Formula (I):
in which M is W or Mo and X and Y are the same or different.
It has now been found that a particular compound not specifically described in any publication has particularly desirable properties. There is therefore provided a compound of the formula II
in which
X is substituted pyrrolide with the general structure of
in which Ra- Rd are independently selected from H, C1-C4 alkyl, C1-C4 alkoxy, aryl, aryloxy, dialkylamino, diarylamino, halogen, trifluoromethyl, cyano, nitro, sulfonyl and sulfinyl;
Y is selected from C1-C6 alkoxy and C1-C10 aryloxy, both of which may be substituted with alkoxy, aryloxy, dialkylamino, diarylamino, halogen, trifluoromethyl, cyano, nitro, sulfonyl and sulfinyl R1 is selected from H, C1-C12 alkyl and 5- to 18-membered aryl, both of which may be substituted with one or more of C1-C12-alkyl, 5- to 18-membered aryl, C1-C12-alkyloxy, di-(C1-C4-alkyl)amino, halogen, trifluoromethyl, cyano and nitro residues;
R2 is selected from C1-C12-alkyl and 5- to 18-membered aryl, both of which may be substituted with one or more of C1-C12 alkyl, 5- to 18-membered aryl, C1-C12-alkyloxy, di(C1-C4alkyl)amino, halogen, trifluoromethyl, cyano, nitro residues;
R3 is selected from C1-C12 alkyl and 5- to 18-membered aryl, both of which may be substituted with one or more of C1-C12 alkyl, 5- to 18-membered aryl, C1-C12-alkoxy, di(C1-C4-alkyl)amino, halogen, trifluoromethyl, cyano and nitro residues; and,
R4-R11 are independently selected from H, C1-C4 alkyl and halogen; and
W is selected from Mo and W.
In this description, wherever the terms are used, “alkyl” and “alkoxy” encompass instances in which the alkyl entity is linear, branched or cycloalkyl, and “aryl” encompasses heteroaryl entities.
In a particular embodiment:
In a further particular embodiment:
In particular embodiments, the compound hereinabove described is selected from compounds of the Formulae III, IV, V and VI:
more particularly the compounds of the Formulae III, IV and V
The compounds of Formula II may be made according to the following general scheme:
In particular, the compound of Formula III is made according to the following scheme:
The starting materials for the preparation of the compounds according to Formula II may be easily prepared according to known methods. Such methods may be found, for example in the paper of Jiang et al (J. Am. Chem. Soc. 2009, 131, 16630-16631).
These compounds have been found to be particularly useful in the catalysis of ring-opening metathesis polymerisation reactions, particularly of dicyclopentadiene. The resulting polydicyclopentadiene has a structure of unusual and desirable stereoregularity. There is therefore also provided the use of a compound of the Formula (II) as hereinabove defined in the preparation of a polymer of dicyclopentadiene.
The catalysts are generated in situ from the compounds of Formula II by art-recognised methods, such as the addition of Lewis acids, typically zinc chloride.
Poly(dicyclopentadiene) (PDCPD) made utilising the compounds hereinabove described is distinguished by having a particularly high cis-content. In the corresponding hydrogenated PDCPD the ratio of racemo diads is at least 75%, and in many cases can exceed 90%, and they are syndiotactic. This stereoregularity provides the hydrogenated PDCPD with a high degree of crystallinity, which in turn confers excellent physical properties, such as high melting point, improved impact resistance, corrosion resistance and heat resistance. PDCPD and hydrogenated PDCPD have a number of mechanical and optical uses.
In contrast, catalysts described in Angew. Chem. Int. Ed. 2011, 50, 8829-7832, and in PCT published application WO 2012/116695, yield PDCPD and hydrogenated PDCPD with low syndiotacticity. For instance, in the hydrogenated PDCPD prepared using Mo(CHCMe2Ph)(NArdiiPr)(OCMe(CF3)2)2(1, 10-phenantroline) the ratio of racemo diads was found to be 39%, and it was not syndiotactic (iso-biased). DSC analysis of the hydrogenated PDCPD showed no melting point, suggesting that the polymer was amorphous. (ArdiiPr=2,6-diisopropyl-phenyl; the complex is an example described in Angew. Chem. Int. Ed. 2011, 50, 8829-7832, and in PCT published application WO 2012/116695.)
The measurement of the polymer parameters are typically performed by the following methods:
(1) Number average molecular weight of dicyclopentadiene ring-opening polymer
(2) Cis/trans content in dicyclopentadiene ring-opening polymer
(3) Hydrogenation ratio of dicyclopentadiene ring-opening polymer during hydrogenation reaction
(4) Thermal behaviour of hydrogenated syndiotactic crystalline dicyclopentadiene ring-opening polymer
(5) Ratio of racemo diads in hydrogenated dicyclopentadiene ring-opening polymer
The disclosure is further described with reference to the following non-limiting examples.
The bispyrrolide precursor W(CHCMe2Ph)(NArdiMe)(Me2Pyr)2 (ArdiMe=2,6-dimethylphenyl, Me2Pyr=2,5-dimethylpyrrolide) (312 mg, 0.5 mmol) was dissolved in benzene (5 mL). Ph(CF3)2COH (84 microL, 0.5 mmol) was added, and the reaction mixture was stirred for 30 min at room temperature. An aliquot of the reaction mixture was analyzed by 1H NMR and 19F NMR to confirm the formation of the MAP complex. 1,10-Phenantroline (90 mg, 0.5 mmol) was added. The reaction mixture was stirred for an hour at room temperature, and then it was moved into the freezer. Next morning the reaction mixture was thawed, yielding part of the product as orange crystals. Precipitation of the product was completed by slow, gradual addition of pentane (10 mL in total). The reaction mixture and a glass filter were cooled in the freezer, and the product was isolated by rapid filtration. It was washed with pentane on the frit, and dried in N2 stream. Orange solid. Isolated yield: 480 mg (quantitative).
1H-NMR (C6D6): 0.72 (s, 3H, N—Ar CH3), 1.77 (s, 3H, CH3 neophylidene), 1.99 (s, 3H, CH3 neophylidene), 2.44 (s, 3H, CH3 2,5-dimethylpyrrole), 2.53 (s, 3H, N—Ar CH3), 2.67 (s, 3H, CH3 2,5-dimethylpyrrole), 6.45 (d, 3JHH=7.5 Hz 1H, N—Ar Cmeta-H), 6.54 (dd, 3JHH=8.1, 5.0 Hz, 1H, H8-phen), 6.61 (t, 3JHH=7.5 Hz, 1H, N—Ar Cpara-H), 6.65 (d, 1H, CH 2,5-dimethylpyrrole),), 6.67 (dd, 3JHH=8.1, 5.2 Hz, 1H, H3-phen), 6.77 (d, 1H, CH 2,5-dimethylpyrrole), 6.93 (d,3JHH=7.5 Hz 1H, N—Ar Cmeta-H), 6.99 (d, 1H, H5-phen), 7.00 (d, 1H, H6-phen), 7.15 (m, 2H, neophylidene Ph Cpara-H, (C6F5)2CH3CO Cpara-H), 7.17 (m, 1H, H7-phen) 7.29 (m, 4H, neophylidene Ph Cmeta-H, (C6F5)2CH3CO Cmeta-H), 7.36 (m, 1H, H4-phen), 7.70 (m, 4H, neophylidene Ph Corto-H, (C6F5)2CH3Corto-H), 8.77 (d, 3JHH=5.0 Hz, 1H, H2-phen), 9.61 (dd, 3JHH=5.2 Hz, 4JHH=1.5 Hz, 1H, H9-phen), 11.99 ppm (s, 1H, W=CH,2JWH=10.0 Hz).
The bispyrrolide precursor W(CHCMe2Ph)(NArdiiPr)(Me2Pyr)2 (ArdiiPr=2,6-diisopropylphenyl, Me2Pyr=2,5-dimethylpyrrolide) (680 mg, 1 mmol) was dissolved in benzene (10 mL). Ph(CF3)2COH (170 microL, 1 mmol) was added, and the reaction mixture was stirred for an hour at room temperature. An aliquot of the reaction mixture was analyzed by 1H and 19F NMR, which confirmed the formation of the MAP complex. 1,10-Phenantroline (180 mg, 1 mmol) was added. The reaction mixture was stirred for an hour at room temperature. An aliquot was analyzed by 1H and 19F NMR. Both methods confirmed the formation of one single stereoisomer of the target compound. The compound was spectroscopically pure. The solution of the complex was concentrated to ca. 3-4 mL. Pentane was added to room temperature. Precipitation of the target compound started after adding ca. 15 mL pentane. Some more pentane (ca. 10 mL) was added to complete precipitation. The mixture was stirred for an hour. The solids were isolated by filtration, washed with pentane, and dried first in N2 stream, and then in vacuum. Ocher solid. Yield: 936 mg (93%). The product was prepared from the isolated MAP complex, too, with similar yields.
1H-NMR (C6D6): −0.20 (d, 3JHH=6.9 Hz, 6H, CH3CHCH3), 0.12 (d, 3JHH=6.9 Hz, 6H, CH3CHCH3), 1.22 (d, 3JHH=6.7 Hz, 6H, CH3CHCH3), 1.41 (d, 3JHH=6.7 Hz, 6H, CH3CHCH3), 1.89 (s, 3H, CH3 neophylidene), 2.20 (sept, 3JHH=6.9 Hz, 1H, CH3CHCH3), 2.24 (s, 3H, CH3 neophylidene), 2.36 (s, 3H, CH3 2,5-dimethylpyrrole), 2.74 (s, 3H, CH3 2,5-dimethylpyrrole), 4.25 (sept, 3JHH=6.7 Hz, 1H, CH3CHCH3), 6.51 (dd, 3JHH=8.1, 5.0 Hz, 1H, H8-phen), 6.63 (d, 3JHH=2.7 Hz, 1H, CH 2,5-dimethylpyrrole), 6.63 (dd, 3JHH=8.1, 5.2 Hz, 1H, H3-phen), 6.65 (d, 3JHH=7.7 Hz 1H, N—Ar Cmeta-H), 6.69 (d, 3JHH=2.7 Hz, 1H, CH 2,5-dimethylpyrrole),), 6.82 (t, 3JHH=7.7 Hz, 1H, N—Ar Cpara-H), 7.00 (ABd, 2H, H5-phen, H6-phen), 7.14-7.20 (m, 2H, neophylidene Ph Cpara-H, OCPh(CF3)2 Cpara-H), 7.15 (d, 3JHH=7.7 Hz 1H, N—Ar Cmeta-H), 7.17 (m, 1H, H7-phen), 7.29 (m, 2H, OCPh(CF3)2 Cmeta-H), 7.34 (m, 1H, H4-phen), 7.37 (m, 2H, neophylidene Ph Cmeta-H), 7.60 (m, 2H, OCPh(CF3)2 Corto-H), 7.81 (m, 4H, neophylidene Ph Corto-H), 9.04 (d br, 3JHH=5.1 Hz, 1H, H2-phen), 9.71 (dd, 3JHH=5.0 Hz, 4JHH=1.2 Hz, 1H, H9-phen), 12.20 ppm (s, 1H, W=CH, 2JWH=9.5 Hz).
The bispyrrolide precursor W(CHCMe2Ph)(NArdiMe)(Me2Pyr)2 (ArdiMe=2,6-dimethylphenyl, Me2Pyr=2,5-dimethylpyrrolide) (156 mg, 0.25 mmol) was dissolved in toluene (10 mL). The solution was cooled to −38 Celsius in the freezer of the glove box. The solution was moved out of the glove box, and (CF3)3COH (35 microL, 0.25 mmol) was added immediately at intensive stirring. The reaction mixture was allowed to warm to room temperature, and and it was left stirring overnight. An aliquot of the reaction mixture was analyzed by 1H and 19F NMR. The analysis confirmed the formation of the MAP complex, and also revealed the formation of a small amount of bisalkoxide (ca. 5 mol %). 1,10-phenantroline (45 mg, 0.25 mmol was added. The reaction mixture turned brownish red immediately. Phenantroline residues were washed into the reaction mixture with toluene (1 mL). The reaction mixture was stirred for an hour. An aliquot of the reaction mixture was analyzed by 1H and 19F NMR. The analysis confirmed the formation of the phenantroline adduct of the MAP complex, and also revealed the formation of a small amount of the phenantroline adduct of the bisalkoxide (ca. 5 mol %). The reaction mixture was concentrated to 1-2 mL, and precipitation of the product was initiated by the slow addition of pentane (ca. 10 mL). The mixture was stirred for an hour at room temperature to triturate the product, and then the reaction mixture was moved into the freezer to complete the precipitation of the target compound. The product was isolated by filtration, and dried on the frit in N2 stream. Red solid. Yield: 200 mg (85%). Purity>95%.
1H-NMR (C6D6) δ (ppm): 0.62 (s, 3H, CH3), 1.82 (s, 3H, CH3), 1.95 (s, 3H, CH3), 2.19 (s, 3H, CH3), 2.47 (s, 3H, CH3), 3.16 (s, 3H, CH3), 6.38-7.35 (m, 14H, aromatic), 7.69 (m, 2H, Cortho-H neophylidene), 8.60 (dd, J=5.2, 1.4 Hz, 1H, H2 Phen), 9.32 (d br, J=5.0 Hz, 1H, H2′ Phen), 12.04 (s, 2JWH=10.9 Hz, 1H, W=CH).
19F-NMR (C6D6) δ (ppm): −72.9 (s).
The compound of Formula VI was prepared from W(CHCMe2Ph)(NArdiMe) (Me2Pyr)2 (ArdiMe=2,6-dimethylphenyl, Me2Pyr=2,5-dimethylpyrrolide) and (CCl3)(CF3)2COH by the method of Example 3. Yield 83%.
1H-NMR (C6D6): δ 0.56 (s, 3H, N—Ar CH3), 1.81 (s, 3H, CH3 neophylidene), 1.93 (s, 3H, CH3 neophylidene), 2.17(s, 3H, CH3 Me2Pyr), 2.43 (s, 3H, N—Ar CH3), 3.17 (s, 3H, CH3 Me2Pyr), 6.40 (d br, 3JHH=7.3 Hz, 1H, N—Ar Cmeta-H), 6.58 (m, 2H, H3-phen, N—Ar Cpara-H), 6.63 (m, 1H, CH Me2Pyr), 6.66 (m, 1H, CH Me2Pyr), 6.65 (m, 1H, H3′-phen), 6.86 (d br,3JHH=7.6 Hz, 1H, N—Ar Cmeta-H), 6.97 (ABq, 2H, H5-phen, H5′-phen), 7.13 (m, 1H, neophylidene Ph Cpara-H), 7.16 (m, 1H, H4′-phen), 7.31 (m, 3H, neophylidene Ph Cmeta-H, H4-phen), 7.68 (m, 2H, neophylidene Ph Corto-H), 8.57 (dd, JHH=5.2, 1.1 Hz, 1H, H2-phen), 9.52 (d br, JHH=4.8 Hz, 1H, H2′-phen), 12.34 ppm (s, 1H, W=CH, 2JWH=12.0 Hz).
19F-NMR (C6D6): δ −65.2 (q, 4JFF=10.5 Hz), −68.0(q, 4JFF=10.5 Hz).
13C-NMR (C6D6): δ 16.7 (N—Ar CH3), 19.0 (N—Ar CH3), 20.6 (CH3 Me2Pyr), 21.2 (CH3 Me2Pyr) 30.2 (CH3 neophylidene), 34.7 (CH3 neophylidene), 55.1 (C neophylidene), 107.7 (CH Me2Pyr), 110.8 (CH Me2Pyr), 123.8 (C3-phen), 124.5 (C3′-phen), 124.9 (N—Ar Cpara), 125.5 (C5-phen), 126.0 (neophylidene Ph Cpara), 127.0 (N—Ar Cmeta), 126.9 (neophylidene Ph Cortho), 126.8 (C5′-phen), 128.3 (neophylidene Ph Cmeta), 128.7 (C4a′-phen, N—Ar Cmeta), 129.2 (C4a-phen), 133.7 (N—Ar Cortho), 137.6 (C4′-phen), 138.4 (C4-phen), 140.4 (N—Ar Cortho), 145.0 (C1a′-phen), 147.2 (C1a-phen), 153.5 (neophylidene Ph Cipso), 154.4 (N—Ar Cipso), 155.3 (C2′-phen), 160.1 (C2-phen), 287.4 ppm (W=CH).
A glass reactor equipped with a stirrer was charged with 0.072 g (1/500 mol/mol) of (2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)2,6-dimethylphenylimidotungsten(VI) (2,5-dimethylpyrrolido)(neophylidene)(1,10-phenanthroline) obtained in Example 1, and 1 g of toluene. After the addition of 5.0 g of dicyclopentadiene, 20.0 g of cyclohexane, 0.21 g of 1-hexene, and a solution prepared by dissolving 0.0105 g of anhydrous zinc chloride in 5 g of 1,4-dioxane, a polymerization reaction was performed at 50° C. White turbidity due to 1,10-phenanthroline-zinc was observed immediately after the initiation of the polymerization reaction. After 3 hours had elapsed, a large quantity of acetone was poured into the reaction mixture to aggregate the precipitate, and the aggregate was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The yield of the resulting ring-opening polymer was 4.3 g, and the ring-opening polymer had a number average molecular weight of 14,000 and a cis content of 97%.
A glass reactor equipped with a stirrer was charged with 2.5 g of the resulting dicyclopentadiene ring-opening polymer and 21 g of p-toluenesulfonylhydrazide. After the addition of 500 ml of p-xylene, a hydrogenation reaction was performed at 125° C. for 5 hours. The reaction mixture was poured into a large quantity of methanol to completely precipitate the resulting hydrogenated dicyclopentadiene ring-opening polymer, which was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The hydrogenation ratio of the resulting hydrogenated ring-opening polymer was 99% or more, and the ratio of racemo diads in the hydrogenated ring-opening polymer was 92% and syndiotactic. DSC analysis of the obtained hydrogenated ring-opening polymer showed a melting point, suggesting its crystalline nature.
A glass reactor equipped with a stirrer was charged with 0.076 g (1/500 mol/mol) of (2-trifluoromethyl-2-phenyl-1,1,1-trifluoroethoxy)2,6-diisopropylphenylimidotungsten(VI) (2,5-dimethylpyrrolido)(neophylidene)(1,10-phenanthroline) obtained in Example 2, and 1 g of toluene. After the addition of 5.0 g of dicyclopentadiene, 20.0 g of cyclohexane, 0.21 g of 1-hexene, and a solution prepared by dissolving 0.0105 g of anhydrous zinc chloride in 5 g of 1,4-dioxane, a polymerization reaction was performed at 50° C. White turbidity due to 1,10-phenanthroline-zinc was observed immediately after the initiation of the polymerization reaction. After 3 hours had elapsed, a large quantity of acetone was poured into the reaction mixture to aggregate the precipitate, and the aggregate was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The yield of the resulting ring-opening polymer was 4.4 g, and the ring-opening polymer had a number average molecular weight of 10,900 and a cis content of 81%.
A glass reactor equipped with a stirrer was charged with 2.5 g of the resulting dicyclopentadiene ring-opening polymer and 21 g of p-toluenesulfonylhydrazide. After the addition of 500 ml of p-xylene, a hydrogenation reaction was performed at 125° C. for 5 hours. The reaction mixture was poured into a large quantity of methanol to completely precipitate the resulting hydrogenated dicyclopentadiene ring-opening polymer, which was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The hydrogenation ratio of the resulting hydrogenated ring-opening polymer was 99% or more, and the ratio of racemo diads in the hydrogenated ring-opening polymer was 78% and syndiotactic. DSC analysis of the obtained hydrogenated ring-opening polymer showed a melting point, suggesting its crystalline nature.
A glass reactor equipped with a stirrer was charged with 0.072 g (1/500 mol/mol) of (nonafluoro-tert-butyl alkoxy)2,6-dimethylphenylimidotungsten(VI) (2,5-dimethylpyrrolido)(neophylidene)(1,10-phenanthroline) obtained in Example 3, and 1 g of toluene. After the addition of 5.0 g of dicyclopentadiene, 20.0 g of cyclohexane, 0.21 g of 1-hexene, followed by a solution of 0.0105 g of anhydrous zinc chloride in 5 g of 1,4-dioxane, a polymerization reaction was performed at 50° C. White turbidity due to the presence of 1,10-phenanthroline-zinc was observed immediately after the initiation of the polymerization reaction. After 1 hour had elapsed, a large quantity of acetone was poured into the reaction mixture to aggregate the precipitate, and the aggregate was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The yield of the resulting ring-opening polymer was 4.7 g, and the ring-opening polymer had a number average molecular weight of 5,500 and a cis content of 94%.
A glass reactor equipped with a stirrer was charged with 2.5 g of the resulting dicyclopentadiene ring-opening polymer and 21 g of p-toluenesulfonylhydrazide. After the addition of 500 ml of p-xylene, a hydrogenation reaction was performed at 125° C. for 5 hours. The reaction mixture was poured into a large quantity of methanol to completely precipitate the resulting hydrogenated dicyclopentadiene ring-opening polymer, which was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure.
The hydrogenation ratio of the resulting hydrogenated ring-opening polymer was in excess of 99% and the ratio of racemo diads in the hydrogenated ring-opening polymer was 93% and syndiotactic. DSC analysis of the obtained hydrogenated ring-opening polymer showed a melting point, suggesting its crystalline nature.
A glass reactor equipped with a stirrer was charged with 0.072 g (1/500 mol/mol) of Mo(CHCMe2Ph)(NArdiiPr)(OCMe(CF3)2)2(1,10-phenantroline), obtained as described in Angew. Chem. Int. Ed. 2011, 50, 8829-7832, and 1 g of toluene. After the addition of 5.0 g of dicyclopentadiene, 20.0 g of cyclohexane, 0.21 g of 1-hexene, followed by a solution of 0.0105 g of anhydrous zinc chloride in 5 g of 1,4-dioxane, a polymerization reaction was performed at 50° C. White turbidity due to the presence of 1,10-phenanthroline-zinc was observed immediately after the initiation of the polymerization reaction. After 1 hour had elapsed, a large quantity of acetone was poured into the reaction mixture to aggregate the precipitate, and the aggregate was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure. The yield of the resulting ring-opening polymer was 4.6 g, and the ring-opening polymer had a number average molecular weight of 3,800 and a cis content of 66%.
A glass reactor equipped with a stirrer was charged with 2.5 g of the resulting dicyclopentadiene ring-opening polymer and 21 g of p-toluenesulfonylhydrazide. After the addition of 500 ml of p-xylene, a hydrogenation reaction was performed at 125° C. for 5 hours. The reaction mixture was poured into a large quantity of methanol to completely precipitate the resulting hydrogenated dicyclopentadiene ring-opening polymer, which was filtered off, washed, and dried at 40° C. for 24 hours under reduced pressure.
The hydrogenation ratio of the resulting hydrogenated ring-opening polymer was 99% or more, and the ratio of racemo diads in the hydrogenated ring-opening polymer was 39% and not syndiotactic (iso-biased). DSC analysis of the obtained hydrogenated ring-opening polymer showed no melting point, suggesting its amorphous nature.
Number | Date | Country | Kind |
---|---|---|---|
1503926.6 | Mar 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2016/051295 | 3/8/2016 | WO | 00 |