CN109692709B - Catalyst for olefin metathesis reaction and preparation and application methods thereof - Google Patents

Abstract

The invention discloses a catalyst for olefin metathesis reaction and preparation and application methods thereof, belonging to the technical field of olefin metathesis catalysis. The chemical structure of the catalyst for olefin metathesis reaction is shown as formula I:

wherein, L is aza five-membered ring carbene; x¹And X²Are the same or different anions; r¹When selected from hydrogen, R²Selected from the group consisting of alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxy, substituted or unsubstituted hydrocarbyl; r³Is cycloalkyl, alkane or aromatic hydrocarbon; r⁴、R⁵Aryl, cycloalkyl, alkane or together form an epoxy group. The catalyst provided by the invention has the advantages of simple preparation method, small catalyst consumption, high reaction rate, stable process and environment-friendly reaction and synthesis, and is mainly applied to the industrial high-efficiency production of olefin metathesis products.

Description

A kind of catalyst for olefin metathesis reaction and its preparation and application method

technical field

The invention belongs to the technical field of olefin metathesis catalysis, in particular to a catalyst for olefin metathesis reaction and a preparation and application method thereof.

Background technique

Since the 1950s, olefin metathesis has important applications because of its synthetic products, and this research has developed rapidly. Olefin metathesis refers to the process of cutting and recombining carbon-carbon double bonds under the catalysis of metals. According to the change of the molecular skeleton during the reaction, it can include cross-metathesis reaction, ring-closing metathesis reaction, ring-opening metathesis reaction, ring-opening metathesis polymerization reaction, and ring-opening metathesis metathesis reaction.

Molybdenum-based and tungsten-based catalysts are the earliest reported olefin metathesis catalysts, but their catalytic activity is low and unstable to water and air. The subsequently reported ruthenium-based catalysts are widely used due to their high activity in different metathesis reactions, tolerance to functional groups, and stability to air and water. Among them, the most commonly used ruthenium-based catalysts are the first, second and third generation Grubbs-type ruthenium catalysts (Gru-Ⅰ, Gru-Ⅱ, Gru-Ⅲ) (Recent advances inruthenium-based olefin metathesis. Grubbs et al. Chem Soc Rev. DOI: 10.1039/c8cs00027a).

In particular, the discovery of Gru-Ⅱ, tricyclohexylphosphine was substituted by Nheterocyclic carbene ligands, which significantly improved the catalytic activity and gained wider application in industrial catalysis.

SUMMARY OF THE INVENTION

The invention provides a new catalyst for olefin metathesis reaction, which is improved on the basis of the second-generation Grubbs type catalyst to obtain a catalyst with a chiral bisphosphineamine binuclear ruthenium carbene complex structure, which is used for olefin metathesis reaction .

The present invention proposes a kind of catalyst of olefin metathesis reaction, and its chemical structure is shown in formula I:

in,

L is aza five-membered ring carbene;

X ¹ and X ² are the same or different anions;

R ¹ and R ² are each independently selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxyl, substituted or unsubstituted hydrocarbon groups; or when R ¹ is selected from hydrogen, R ² is selected from alkane oxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxy, substituted or unsubstituted hydrocarbyl;

R ³ is cycloalkyl, alkane or aromatic hydrocarbon;

R ⁴ and R ⁵ are the same or different aryl, cycloalkyl, straight-chain, branched-chain alkanes, or R ⁴ and R ⁵ are joined together to form a cycloalkyl group.

Further, R ³ is isopropyl, cyclohexyl, tert-butyl or phenyl; preferably R ³ is cyclohexyl.

Further, R ⁴ and R ⁵ are each independently selected from n-propyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl or phenyl; preferably, both R ⁴ and R ⁵ are phenyl.

Further, X ¹ and X ² are independently selected from halogen Cl, Br or I.

Further, L is an aza five-membered ring carbene, including saturated or unsaturated aza five-membered ring carbene, whose structural formulas are shown in formula IIa and IIb, respectively,

Wherein, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ are each independently selected from: hydrogen, substituted or unsubstituted primary or secondary alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, Substituted or unsubstituted anthracenyl, halogen, hydroxyl, mercapto, cyano, thiocyano, amino, nitro, nitroso, sulfonic acid, boroxy, dihydroxyboron, phosphonic acid, phosphine acid, phosphorous, phosphino and silyloxy.

The present invention also proposes a preparation method of a catalyst for olefin metathesis reaction, comprising the following steps:

a) Under nitrogen protection, dissolving chiral primary diamine and triethylamine in solvent tetrahydrofuran, stirring to obtain amine solution; dissolving the corresponding compound of double-substituted phosphine chloride in solvent tetrahydrofuran to obtain phosphine chloride solution; dissolving chlorine After the phosphine solution is slowly added dropwise to the amine solution for mixing reaction, the solvent is drained, anhydrous ethanol is added for filtration, and the solid is washed with n-hexane and drained to obtain the chiral bisphosphine amine ligand;

b) Under the protection of nitrogen, the metal ruthenium carbene complex is dissolved in the solvent toluene, after adding pyridine to mix the reaction, adding n-hexane and stirring, precipitating, filtering, washing, and draining the solvent to obtain a pyridine-coordinated ruthenium carbene complex thing;

c) Under nitrogen protection, the chiral bisphosphine amine ligand obtained in step a) is dissolved in solvent toluene or dichloromethane, and the pyridine-coordinated ruthenium carbene complex obtained in step b) is dissolved in solvent toluene or dichloromethane Methane is added dropwise to the solution of the chiral bisphosphine amine ligand, after the reaction, the solvent is drained, n-hexane is filtered, and the obtained filtrate is drained to obtain the ruthenium carbene compound coordinated by the chiral bisphosphine amine, that is, the catalyst for the olefin metathesis reaction.

Further, in the step a), the consumption of the chiral primary diamine is 1 equivalent, and the consumption of the triethylamine is 2-3 equivalents; in the step c), the consumption of the chiral bisphosphine amine ligand is 1 equivalent In equivalents, the amount of the pyridine-coordinated ruthenium carbene complex was 2 equivalents.

The present invention also provides an application method of a catalyst for olefin metathesis reaction. The olefin metathesis reaction includes cross metathesis reaction, ring-closing metathesis reaction, ring-opening metathesis reaction, ring-opening metathesis polymerization reaction and ring-opening metathesis metathesis reaction.

Further, the application method includes the following steps: after the reaction raw material olefin and the catalyst are reacted in the reaction flask, the solvent is drained, and the product is separated through a column.

Further, the reaction temperature is 0-80° C., and the molar ratio of the catalyst to the olefin is 1:1-100,000.

The catalyst of the proposed olefin metathesis reaction of the present invention has the following advantages:

The invention improves on the basis of the second generation Grubbs type catalyst, and provides a catalyst with a chiral bisphosphine amine binuclear ruthenium carbene complex structure and a preparation and application method thereof. The catalyst preparation method is simple, the reaction rate is fast, the catalyst dosage is small, the production efficiency is high, the process is stable, the molecular weight distribution of the product is uniform, and the catalyst is suitable for industrialized and efficient production of olefin metathesis products.

Detailed ways

It should be noted that the embodiments disclosed in the present disclosure and the features of the embodiments may be combined with each other under the condition of no conflict.

The embodiment of the present invention proposes a kind of catalyst of olefin metathesis reaction, and its chemical structure is as shown in formula I:

in,

L is aza five-membered ring carbene;

X ¹ and X ² are the same or different anions;

R ¹ and R ² are each independently selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxyl or substituted or unsubstituted hydrocarbon groups; or when R ¹ is selected from hydrogen, R ² is selected from alkane oxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxy, substituted or unsubstituted hydrocarbyl;

R ³ is cycloalkyl, alkane or aromatic hydrocarbon;

R ⁴ and R ⁵ are the same or different aryl, cycloalkyl, straight-chain, branched-chain alkanes, or R ⁴ and R ⁵ are joined together to form a cycloalkyl group.

The invention is improved on the basis of the second-generation Grubbs type ruthenium catalyst, and proposes a catalyst for olefin metathesis reaction. The chiral PNCCNP bisphosphine amine ligand is synthesized by using chiral raw materials, and the phosphorus atoms in the ligand can be formed with metal ruthenium. The coordination bond finally obtains a chiral bimetallic catalyst. The bimetallic catalyst can rapidly increase the reaction rate of the olefin metathesis reaction, reduce the amount of catalyst and improve the production efficiency. At the same time, the product has a uniform molecular weight distribution, which is suitable for the industrialized and efficient production of olefin metathesis products.

Although great breakthroughs have been made in the study of olefin metathesis, there are still many challenges. Further breakthroughs are needed in terms of reaction rate, efficient utilization of catalysts, etc., to promote the industrial application of olefin metathesis reactions, all of which are issues that need to be addressed.

In the prior art, it has been reported that in the second generation Grubbs-type ruthenium catalyst, due to the difference in the structure and properties of the trialkyl or triphenylphosphine ligands, the coordination of the phosphine ligands and the metal ruthenium is affected, thereby Affects catalyst activity and reaction rate. Some attempts have also been made to improve the second-generation Grubbs-type ruthenium catalysts by using phosphine ligands containing electron-withdrawing substituents, but the catalytic effect, especially the reaction rate, has not been significantly improved.

On the basis of the second generation Grubbs type ruthenium catalyst, the present invention improves the catalyst and improves the catalytic performance through the bisphosphine amine ligand doped with P-X bond (wherein X is an electronegative heteroatom). The chiral PNCCNP bisphosphine amine ligand is used to form a coordination bond with the central metal atom ruthenium to finally obtain a chiral bimetallic catalyst, thereby changing the structure and properties of the catalyst, so that the carbene ligand on the catalyst and the chiral PNCCNP bisphosphine amine Better coordination and synergy are formed between the ligand and the double-center metal atom ruthenium, which work together from the aspects of steric hindrance and electronic effects, thereby improving the reaction rate and catalytic activity of the catalyst.

In an embodiment of the present invention, L is an aza five-membered ring carbene, including a saturated or unsaturated aza five-membered ring carbene, whose structural formulas are shown in formula IIa and IIb, respectively,

Wherein, R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ are each independently selected from: hydrogen, substituted or unsubstituted primary or secondary alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, Substituted or unsubstituted anthracenyl, halogen, hydroxyl, mercapto, cyano, thiocyano, amino, nitro, nitroso, sulfonic acid, boroxy, dihydroxyboron, phosphonic acid, phosphine acid, phosphorous, phosphino and silyloxy. In the present invention, L is an aza five-membered ring carbene, which is beneficial to improve catalytic activity because of the diversity of N-heterocyclic carbene ligand spherical shapes.

In the embodiment of the present invention, X ¹ and X ² are independently selected from halogen Cl, Br or I; preferably, X ¹ and X ² are both halogen Cl.

In one embodiment of the present invention, R ¹ and R ² are each independently selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxyl, substituted or unsubstituted hydrocarbyl; or R ¹ is selected from When hydrogen, R ² is selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxyl, substituted or unsubstituted hydrocarbyl, and hydrocarbyl can be substituted by the following groups: alkyl, aryl, Alkenyl, alkynyl, metallocene, halogen, nitro, nitroso, hydroxy, alkoxy, aryloxy, amino, amido, carboxyl, carbonyl, thio or amido.

Preferably, R ¹ is hydrogen, and R ² is a substituted or unsubstituted hydrocarbon group; more preferably, R ¹ is hydrogen, and R ² is a substituted or unsubstituted aryl group; more preferably, R ¹ is hydrogen, and R ² is phenyl.

In yet another embodiment of the present invention, R ³ can be a cycloalkyl, an alkane, an aromatic hydrocarbon, or the like. Specifically, R ³ can be isopropyl, cyclohexyl, tert-butyl or phenyl and the like. Preferably R ³ is cyclohexyl or phenyl.

In an embodiment of the present invention, R ⁴ and R ⁵ can be aryl, cycloalkyl, alkane, or R ⁴ and R ⁵ are connected together to form a cycloalkyl group, or the like. Specifically, R ⁴ and R ⁵ are phenyl or R ⁴ and R ⁵ together form cyclohexyl and the like.

In the embodiment of the present invention, a chiral PNCCNP bisphosphine amine ligand with a special structure is used to form a coordination effect with the carbene ligand and the central metal atom ruthenium, which acts together from the aspects of steric hindrance and electronic effect. The different types of R ³ , R ⁴ , and R ⁵ substituents on the ligand, as well as the synergistic effect and coordination effect of bimetallic ruthenium under the action of different substituents, will affect the insertion of olefin molecules, thereby affecting the catalytic reaction rate. .

In a preferred embodiment of the present invention, the catalyst of olefin metathesis reaction, its chemical structural formula is as shown in formula I:

in,

L is aza five-membered ring carbene;

X ¹ and X ² are the same or different anions; preferably, X ¹ and X ² are independently selected from halogen Cl, Br or I; more preferably, X ¹ and X ² are both halogen Cl;

R ¹ and R ² are each independently selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, or hydroxyl, substituted or unsubstituted hydrocarbon groups; or when R ¹ is selected from hydrogen, R ² is selected from Alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxyl, substituted or unsubstituted hydrocarbyl, which may be substituted by the following groups: alkyl, aryl, alkenyl, alkyne, respectively group, metallocene group, halogen, nitro, nitroso, hydroxyl, alkoxy, aryloxy, amino, amido, carboxyl, carbonyl, thio or amido; preferably, R ¹ is hydrogen, R ² is substituted or unsubstituted hydrocarbyl; more preferably, R ¹ is hydrogen, and R ² is substituted or unsubstituted aryl; more preferably, R ¹ is hydrogen, and R ² is phenyl;

R ³ can be cycloalkyl, alkane or aromatic hydrocarbon, preferably cycloalkyl, alkane or aromatic hydrocarbon, more preferably R ³ is cyclohexyl;

R ⁴ and R 5 are aryl, cycloalkyl, alkane; or R ⁴ and R ⁵ are connected together to form cycloalkyl. Preferably R ⁴ is n-propyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl or phenyl; more preferably R ⁴ and R5 are phenyl.

The present invention also proposes a preparation method of a catalyst for olefin metathesis reaction, comprising the following steps:

a) Under nitrogen protection, dissolve 1 equivalent of chiral primary amine and 2-3 equivalents of triethylamine in solvent tetrahydrofuran, stir to obtain amine solution; dissolve 2 equivalents of disubstituted phosphine chloride in solvent tetrahydrofuran to obtain phosphine chloride solution; after the amine solution and the phosphine chloride solution are mixed and reacted, the solvent is drained, anhydrous ethanol is added for filtration, and the obtained solid is washed with n-hexane to obtain a chiral bisphosphine amine ligand;

The reaction formula is as follows:

b) Under the protection of nitrogen, the metal ruthenium carbene complex is dissolved in the solvent toluene, after adding pyridine to mix the reaction, adding n-hexane and stirring, precipitating, filtering, washing, and draining the solvent to obtain a pyridine-coordinated ruthenium carbene complex thing;

The reaction formula is as follows:

c) Under nitrogen protection, dissolve 2 equivalents of the pyridine-coordinated ruthenium carbene complex obtained in step b) in a solvent toluene or dichloromethane, and dissolve 1 equivalent of the chiral bisphosphine amine ligand obtained in step a). After the solvent is toluene or dichloromethane, after the two are mixed and reacted, the solvent is drained, the n-hexane is filtered, and the obtained filtrate is drained to obtain a dinuclear chiral ruthenium carbene compound coordinated by a chiral bisphosphine amine, that is, a catalyst for the olefin metathesis reaction. ;

The reaction formula is as follows:

It should be pointed out that Cy, Py and Mes appearing in the chemical formula are the abbreviations for cyclohexyl, pyridyl and mesityl respectively.

Further, in step b), the amount of metal ruthenium carbene complex and pyridine can be 1 mmol metal ruthenium carbene complex: 2-10 mL of pyridine.

The present invention also provides an application method of a catalyst for olefin metathesis reaction. The olefin metathesis reaction includes cross metathesis reaction, ring-closing metathesis reaction, ring-opening metathesis reaction, ring-opening metathesis polymerization reaction, and ring-opening metathesis metathesis reaction.

In one embodiment of the present invention, an application method of a catalyst for an olefin metathesis reaction includes the following steps: after the reaction raw material olefin and the catalyst are reacted in a reaction flask, the solvent is drained, and the product is separated through a column, and then the ring-opening metathesis is performed. The polymerized reaction product was washed with methanol to obtain a polymer. Wherein, the reaction raw material olefin can be any olefin that can undergo metathesis reaction, such as diethyl diallyl malonate, norbornene and the like. The metathesis reaction may be carried out for one olefin alone, or the ring-opening metathesis polymerization reaction may be carried out for two identical or different olefins.

Further, the reaction temperature is 0-80°C; preferably, the reaction temperature is 20-40°C. This temperature range is favorable for the olefin metathesis reaction, and it is not favorable for the reaction to proceed if the temperature is too high or too low.

Further, the molar ratio of catalyst to olefin is 1:1-100000. For example, it can be 1:2, 1:50, 1:100, 1:1000, 1:2000, 1:5000, 1:100000, etc. Selecting appropriate reaction ratios for different olefin feedstocks is beneficial to the improvement of olefin metathesis reaction activity and reaction rate.

The present invention will be described in detail below with reference to specific embodiments.

Example 1

The catalyst 1# for preparing the olefin metathesis reaction, the chemical structural formula is as follows, comprises the following steps:

a) Under nitrogen protection, add 114.19 mg (1R, 2R)-cyclohexanediamine and 303.57 mg triethylamine to a 50 mL eggplant-shaped bottle, mix with 15 mL tetrahydrofuran, and then add 465.46 mg dicyclohexyl phosphine chloride Diluted with tetrahydrofuran, slowly added dropwise to the eggplant-shaped bottle, stirred for 8 hours, a white precipitate was precipitated, the solvent was drained, anhydrous ethanol was added, stirred and filtered, the solid was washed with n-hexane, and the filtrate was concentrated and placed in a refrigerator for recrystallization , a white solid was obtained, the liquid was transferred, and the white solid was drained to obtain a chiral bisphosphonamine ligand.

b) Under nitrogen protection, put 800 mg of Gru-II ruthenium complex in a 100 mL eggplant-shaped flask, add 1 mL of toluene, then add 7 mL of pyridine to react for 10 min, and then add 50 mL of n-hexane and stir for 20 min to precipitate a green solid, filter After washing with n-hexane, suction dry to obtain light green solid.

c) Under nitrogen protection, 72.74 mg of the pyridine-coordinated ruthenium carbene compound obtained in b) was placed in a 25 mL eggplant-shaped flask and dissolved in 3 mL of toluene, and then 25.34 mg of the monophosphine amine ligand obtained in a) was dissolved in 1 mL of toluene It was added dropwise to an eggplant-shaped bottle, reacted at room temperature for 10 minutes, the solvent was removed, n-hexane was added, and the solid was filtered, washed, and dried to obtain a reddish-brown solid catalyst 1# (yield 75 mg, yield 87%).

The NMR characterization of catalyst 1# is as follows:

¹ H NMR (400 MHz, Rt; in C ₆ D ₆ ): δ 19.59 (s, 2H), 8.18 (br s, 4H), 7.14-7.10 (t, 2H), 6.97-6.93 (t, 4H), 6.88-6.86(d,4H),6.24(br s,4H),3.79-3.73(t,2H),3.35-3.30(t,4H),,3.25-3.18(q,4H),,2.76(br s ,12H),2.40(br s,6H),2.33(br s,6H),2.17(s,6H),2.11-2.01(m,6H),1.84(s,6H),1.64-1.53(t,22H) ),,1.45-1.40(br d,6H),,1.14-1.13(q,12H),,1.04-0.96(m,3H).

³¹ P NMR (162 MHz; C6D6): δ 73.40(s).

Example 2

The catalyst 2# for preparing the olefin metathesis reaction, the chemical structural formula is as follows, comprises the following steps:

a) Under nitrogen protection, add 212.30mg (1S,2S)-1,2-diphenylethylenediamine and 303.57mg triethylamine into a 50mL eggplant-shaped bottle, mix with 15mL tetrahydrofuran, and then add 465.46mg Dicyclohexyl phosphine chloride was diluted with tetrahydrofuran, slowly added dropwise to the eggplant-shaped bottle, and after stirring for 8 hours, a white precipitate was precipitated. Concentrate and recrystallize in a refrigerator to obtain a white solid, transfer the liquid, and dry the white solid to obtain a nitrogen phosphine ligand.

b) Same as Example 1.

c) Under nitrogen protection, 72.74 mg of the pyridine-coordinated ruthenium carbene compound obtained in b) was placed in a 25 mL eggplant-shaped flask and dissolved in 3 mL of toluene, and then 30.24 mg of the monophosphine amine ligand obtained in a) was dissolved in a small amount of toluene It was added dropwise to an eggplant-shaped bottle, reacted at 40° C. for 5 minutes, the solvent was removed, n-hexane was added, and the solid was filtered, washed, and drained to obtain a reddish-brown solid catalyst 2#. (yield 62.51 mg, yield 71.7%)

The NMR characterization of catalyst 2# is as follows:

¹ H NMR(400MHz, CDCl3)δ19.41(s,2H),7.13-7.09(t,7H),7.06-7.00(q,3H),6.96-6.92(d,7H),6.86-6.76(br m ,6H),6.52-6.43(br m,3H),5.85(br s,2H),4.51-4.46(t,2H),3.39-3.33(q,2H),3.29-3.21(m,5H),3.13 -3.09(t,2H),2.90-2.85(br d,7H),2.67(s,6H),2.56(br s,6H),2.39-2.33(s,4H),2.23(s,6H),2.11 -2.09(m,8H),1.80(s,10H),1.64(br s,3H),1.47-1.43(m,7H),1.17-1.14(m,9H),1.01-0.95(m,6H), 0.63-0.57(t,3H),0.50-0.46(d,3H),0.29-0.23(d,3H).

³¹ P NMR (162 MHz; C6D6): δ78.41(s).

Example 3

a) Under nitrogen protection, add 212.30mg (1S,2S)-1,2-diphenylethylenediamine and 303.57mg triethylamine into a 50mL eggplant-shaped bottle, mix with 15mL tetrahydrofuran, and then add 441.28mg Diphenylphosphine chloride was diluted with tetrahydrofuran and slowly added dropwise to the eggplant-shaped bottle. After stirring for 8 hours, a white precipitate was precipitated. After that, the solvent was drained, and anhydrous was added to stir and filter. The solid was washed with n-hexane, and the filtrate was Concentrate and recrystallize in a refrigerator to obtain a white solid, transfer the liquid, and dry the white solid to obtain a nitrogen phosphine ligand.

b) Same as Example 1.

c) Under nitrogen protection, 72.74 mg of the pyridine-coordinated ruthenium carbene compound obtained in b) was placed in a 25 mL eggplant-shaped flask and dissolved in 3 mL of toluene, and then 29.03 mg of the monophosphine amine ligand obtained in a) was dissolved in a small amount of toluene It was added dropwise to the eggplant-shaped bottle, reacted for 5 min, the solvent was removed, n-hexane was added, and the solid was filtered, washed, and dried to obtain a reddish-brown solid catalyst 3#. (yield 58.58mg, yield 68.2%)

The NMR characterization of catalyst 3# is as follows:

¹ H NMR(400MHz, CDCl3)δ19.09(s,2H),7.62-7.41(m,8H),7.32-7.19(m,16H),7.01-6.91(m,14H),6.74-6.66(br m ,10H),6.53-6.45(br m,4H),5.80(br s,2H),3.44-3.40(m,8H),2.02(s,6H),1.94(s,8H),1.80(s,10H ),1.21-1.17(m,10H)

³¹ P NMR (162 MHz; C6D6): δ 67.23(s).

Example 4

Catalyst 1#, 2# and 3# are N,N-diallyl-p-toluenesulfonamide as raw materials to carry out metathesis reaction, as follows:

Under nitrogen protection, 0.005 mmol of catalyst was placed in the NMR tube, 0.5 mL of deuterated benzene solvent was added, and 12.56 mg (0.5 mmol) of N,N-diallyl-p-toluenesulfonamide raw material was added. The whole process was carried out by ¹ H NMR. Detect reaction raw material reaction amount, the results are shown in Table 1:

Table 1 Evaluation results of catalysts 1#, 2#, 3# and the second generation Grubbs catalyst

It can be seen from the above experiments that the initial reaction rate of catalyst 1# and catalyst 2# is faster than that of catalyst 3#, the reaction time is long enough and the conversion rate is close to 100%, and the reaction rate is better than that of Gru-Ⅱ catalyst.

Example 5

Catalyst 2# carries out metathesis reaction when the raw material is diethyl diallyl malonate, as follows:

Under nitrogen protection, 0.2 μmol of catalyst 2# and 4 mL of toluene solvent were added to a 25 mL eggplant bottle, and then 96.12 mg (0.4 mmol) of diethyl diallyl malonate was added, and the reaction was carried out at 25°C for 6 h. After GC detection, it was found that the raw materials were completely reacted, the solvent was drained, and 82.1 mg of the product was obtained after passing through the flash column, and the yield was 96.70%.

Example 6

Catalyst 1#, Catalyst 2#, and Catalyst 3# are in the ring-opening metathesis polymerization reaction of norbornene as the raw material, as follows:

Table 2 Evaluation results of catalysts 1#, 2#, 3# and the first and second generation Grubbs catalysts

Catalyst 1#, Catalyst 2# and Catalyst 3# are bimetallic catalysts, that is, there are two metal active centers, and the amount of catalyst is doubled compared to that of single-active center catalysts. Compared with the mononuclear catalysts Gru-I and Gru-II in the prior art, the products catalyzed by bimetallic catalysts have a polymer dispersibility index (PDI) closer to 1, that is, the molecular weight distribution is more uniform; in addition, the molecular weight is slightly larger than the existing ones. Technical catalyst, the cis-selectivity of the product has also been improved.

The above are only preferred embodiments disclosed by the present invention, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the present invention. within the scope of public protection.

Claims (8)

1. A method for preparing a catalyst for olefin metathesis, comprising the steps of:

a) under the protection of nitrogen, dissolving chiral primary diamine and triethylamine in tetrahydrofuran solvent, and stirring to obtain an amine solution; dissolving a corresponding disubstituted phosphine chloride compound in tetrahydrofuran serving as a solvent to obtain a phosphine chloride solution; slowly dripping a phosphine chloride solution into an amine solution for mixing reaction, draining the solvent, adding absolute ethyl alcohol for filtering, washing the solid with n-hexane, and draining to obtain a chiral diphosphine amine ligand;

b) under the protection of nitrogen, dissolving a metal ruthenium carbene complex in a solvent toluene, adding pyridine, mixing, reacting, adding n-hexane, stirring, precipitating, filtering, washing, and draining the solvent to obtain a pyridine-coordinated ruthenium carbene complex;

c) under the protection of nitrogen, dissolving the chiral diphosphine ligand obtained in the step a) in a solvent of toluene or dichloromethane, dissolving the pyridine-coordinated ruthenium carbene complex obtained in the step b) in the solvent of toluene or dichloromethane, dripping the solution into the solution of the chiral diphosphine ligand, after the reaction, draining the solvent, filtering n-hexane, and draining the obtained filtrate to obtain a chiral diphosphine-coordinated ruthenium carbene compound, namely a catalyst for olefin metathesis reaction;

the chemical structure of the catalyst for olefin metathesis reaction is shown as formula I:

wherein,

l is aza five-membered ring carbene;

X¹and X²Are the same or differentAn anion;

R¹and R²Each independently selected from alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxy, substituted or unsubstituted hydrocarbyl; or R¹When selected from hydrogen, R²Selected from the group consisting of alkoxy, alkylsulfonyl, alkylsulfinyl, silyl, hydroxy, substituted or unsubstituted hydrocarbyl;

R³is cycloalkyl, isopropyl, cyclohexyl, tert-butyl or phenyl;

R⁴and R⁵Each independently selected from n-propyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl or phenyl, or R⁴And R⁵Linked together to form a cycloalkyl group.

2. The method of claim 1, wherein the chiral primary diamine is used in an amount of 1 equivalent and the triethylamine is used in an amount of 2 to 3 equivalents in the step a); in the step c), the dosage of the chiral diphosphine ligand is 1 equivalent, and the dosage of the ruthenium carbene complex coordinated by pyridine is 2 equivalents.

3. The method of claim 1, wherein X is¹、X²Each independently selected from the group consisting of halogen Cl, Br, or I.

4. The method of claim 1, wherein L is an aza five-membered ring carbene, including saturated or unsaturated aza five-membered ring carbenes, having the structural formulas shown in formulas IIa and IIb,

wherein R is⁶、R⁷、R⁸、R⁹、R¹⁰Each independently selected from hydrogen, substituted or unsubstituted primary or secondary alkyl, substituted or unsubstituted phenyl,Substituted or unsubstituted naphthyl, substituted or unsubstituted anthryl, halogen, hydroxyl, mercapto, cyano, thiocyanato, amino, nitro, nitroso, sulfonic, oxyboroyl, borono, phosphonic, phosphinic, phospho, phosphino, and siloxy.

5. A catalyst for olefin metathesis prepared by the process of any one of claims 1 to 4.

6. The method of using a catalyst for olefin metathesis as recited in claim 5, wherein the olefin metathesis reaction includes a cross metathesis reaction, a ring closing metathesis reaction, and a ring opening metathesis reaction.

7. The method of using a catalyst for olefin metathesis according to claim 6, comprising the steps of: after the reaction of the reaction raw material olefin and the catalyst in a reaction bottle, the solvent is pumped to dryness, the product is obtained by column separation, and the product of the ring-opening metathesis polymerization reaction is washed by methanol to obtain the polymer.

8. The method of using a catalyst for olefin metathesis according to claim 6, wherein the reaction temperature is 0 to 80 ℃ and the molar ratio of the catalyst to the olefin is 1:1 to 100000.