Sulfur-containing chiral bridged metallocene compounds, their preparation and use

Abstract

The application discloses a kind of chiral bridged metallocene compounds containing sulfur, which is described as the compound of general formula (I): Wherein, R1 is selected from one of 4-substituted phenyl, 2-naphthyl;R2, R3 is selected from alkyl;M is selected from one of TI, Zr, Hf;X is selected from halogen.The application also discloses the preparation and application of the chiral bridged metallocene compounds containing sulfur.Using this method to synthesize metallocene compounds shares intermediate, avoids some dangerous and harmful reagents in the reaction process, and is more suitable for scale-up production.

Description

TECHNICAL FIELD

[0001] The present application relates to a chiral bridged metallocene compound containing sulfur and its preparation and use. BACKGROUND

[0002] Polypropylene material is a kind of excellent performance material, widely used in clothing, daily necessities, medical and health, food industry and other aspects, with the continuous improvement of processing technology, the catalyst required for the production of polypropylene is also more and more strict. In the early 1980s, Sinn (Angew. Chem. Int. Ed. Engl., 1980, 92, 396) and Kaminsky (Macromol. Chem., Rapid Commun., 1983, 4, 417) found that the homogeneous catalytic olefin polymerization system composed of metallocene complex and MAO can catalyze olefin polymerization with high activity. The discovery of methylaluminoxane promotes the rapid development of this field. The activity of metallocene and other transition metal complexes activated by methylaluminoxane is more than 10 times higher than that of Ziegler-Natta catalyst, and has the characteristics of polymer molecular weight distribution and adjustable stereoregularity of polymer (Chem. Rev., 2000, 100:1253).

[0003] Chiral-metallocene catalysts mainly adjust the structure of polypropylene by regulating the chiral structure of the catalyst. The central metal cation of the racemic structure activated by the metallocene compound with C2 symmetry is non-chiral, but due to the steric hindrance, only the monomer with the same chirality as the growing chain is more likely to participate in coordination during the polymerization process, so that isotactic polypropylene can be obtained (J. Organomet. Chem., 1982, 232(3):233-47). The bridged metallocene catalyst has more excellent catalytic performance (Macromolecules, 2002, 35:5382-5387), and is widely used in the design and synthesis of metallocene zirconium. The metallocene zirconium complex with SiMe2 bridge and (2-methyl-4-phenyl) substitution (SBI type) has good activity and can catalyze the preparation of high isotactic polypropylene, showing great potential in the development of isotactic polypropylene (Angewandte Chemie International Edition in English, 1980, 19(11):857-875.). SUMMARY

[0004] The present application aims to provide a new chiral bridged metallocene compound containing sulfur.

[0005] As an aspect of the present application, a chiral bridged metallocene compound containing sulfur is provided, which is a compound according to general formula (I):

[0006]

[0007] wherein,

[0008] R1 is selected from one of 4-substituted phenyl, 2-naphthyl;

[0009] R2, R3 are selected from alkyl;

[0010] M is selected from one of TI, Zr, Hf;

[0011] X is selected from halogen.

[0012] In at least one possible embodiment, R1 is selected from one of 4-t-butylphenyl, 4-fluorophenyl, 4-methoxyphenyl, 2-naphthyl.

[0013] In at least one possible embodiment, R2, R3 are both methyl.

[0014] In at least one possible embodiment, X is chlorine.

[0015] As another aspect of the present application, a method for preparing the above-mentioned sulfur-containing chiral bridged metallocene compound is provided, comprising:

[0016] (1) reacting a thiofuran compound of formula (II) with an acrylic compound of formula (III) according to equation one under the condition of 60-80°C and Eaton's reagent catalysis to obtain a compound of formula (IV);

[0017]

[0018] wherein, R2 and R3 are alkyl;

[0019] (2) dissolving aluminum chloride and the compound of formula (IV) in a polar solvent respectively, mixing them, adding a bromination reagent, and reacting to obtain a compound of formula (V) according to equation two;

[0020]

[0021] wherein, R2 and R3 are alkyl;

[0022] (3) dissolving the compound of formula (V) in a polar solvent, adding a reducing reagent to perform a reduction reaction, and obtaining a compound of formula (VI) according to equation three, dissolving the compound of formula (VI) in a benzene solvent, adding an organic acid catalyst, and making the compound of formula (VI) perform an intramolecular dehydration reaction to obtain a compound of formula (VII);

[0023]

[0024] wherein R2 and R3 are alkyl;

[0025] (4) as shown in equation four, halogenated zinc is added to anhydrous solvent, aryl Grignard reagent as shown in general formula (VIII) is added under nitrogen atmosphere, compound as shown in general formula (VII) is added, stirring, catalyst is added, reaction under the condition of 60ˉ80℃ to obtain ligand precursor as shown in general formula (IX);

[0026]

[0027] wherein,

[0028] R1 is 4-substituted phenyl, 2-naphthyl;

[0029] R2 and R3 are alkyl;

[0030] (5) as shown in equation five, compound as shown in general formula (IX) is added to anhydrous ether solvent, n-butyllithium is added under alcohol liquid nitrogen bath and nitrogen protection, dichlorodimethylsilane is added under low temperature condition, reaction to obtain ligand as shown in general formula (X);

[0031]

[0032] wherein,

[0033] R1 is 4-substituted phenyl, 2-naphthyl;

[0034] R2 and R3 are alkyl;

[0035] (6) as shown in equation six, ligand as shown in general formula (IX) is added to ether solvent, n-butyllithium reagent is added under low temperature condition; metal halide MX4 is added under low temperature condition, reaction at room temperature to obtain target compound as shown in general formula (I);

[0036]

[0037] wherein,

[0038] R1 is 4-substituted phenyl, 2-naphthyl;

[0039] R2 and R3 are alkyl;

[0040] M is one of titanium, zirconium and hafnium;

[0041] X is halogen.

[0042] In at least one possible embodiment, the reaction temperature of step (1) is 80℃, and the reaction time is 1h.

[0043] In at least one possible implementation, in step (2), the polar solvent is chloroform, the brominating agent is liquid bromine, and the molar ratio of the compound of general formula (IV) to the brominating agent is 1:1.1.

[0044] In at least one possible implementation, in step (3), the polar solvent is a mixed solution of an alcohol solvent and an ether solvent; the alcohol solvent is any one or more of methanol, ethanol, and butanol, the ether solvent is any one or more of diethyl ether, methyl tert-butyl ether, and tetrahydrofuran, the volume ratio of the ether solvent to the alcohol solvent is 1-3:1, and the reducing agent is one of sodium borohydride, lithium aluminum hydride, potassium borohydride, and sodium cyanoborohydride.

[0045] In at least one possible implementation, in step (3), the organic acid is one or more of p-toluenesulfonic acid, formic acid, and acetic acid, the compound of general formula (VI) is subjected to intramolecular dehydration to obtain the compound of general formula (VII), one or more of toluene, benzene, xylene, mesitylene, and chlorobenzene is used as the reaction solvent, the molar ratio of the compound of general formula (VI) to the organic acid is 70:1, and the reaction time is 15 min.

[0046] In at least one possible implementation, in step (4), the aryl Grignard reagent as shown in general formula (VIII) is one of 4-methoxyphenyl magnesium bromide, 4-tert-butylphenyl magnesium bromide, 4-fluorophenyl magnesium bromide, and 2-naphthyl magnesium bromide, the halogenated zinc is zinc chloride, the catalyst is one of palladium acetate, diphenylphosphin ferrocene dichloropalladium, palladium tetra-triphenylphosphine, dichlorobis-triphenylphosphine palladium, and bis(tri-tert-butylphosphine)palladium, preferably bis(tri-tert-butylphosphine)palladium, one of nickel acetate, diphenylphosphin ferrocene dichloronickel, nickel tetra-triphenylphosphine, dichlorobis-triphenylphosphine nickel, and bis(tri-tert-butylphosphine)nickel, the molar ratio of the catalyst to the compound of general formula (VII) is 0.23:1, the reaction temperature is specifically 80°C, and the anhydrous solvent is any one or more of tetrahydrofuran, diethyl ether, and toluene.

[0047] In at least one possible implementation, the catalyst is bis(tri-tert-butylphosphine)palladium.

[0048] In at least one possible implementation, in step (5), the anhydrous ether solution is a tetrahydrofuran solution, and the reaction time is specifically 16 h.

[0049] In at least one possible implementation, in step (6), the ether solvent is diethyl ether, and the molar ratio of n-butyllithium to the compound of general formula (IX) to the metal halide is 2:2:1, where M is one of titanium, zirconium, and hafnium, and X is halogen.

[0050] As a further aspect of the present application, there is provided the use of the above-mentioned sulfur-containing chiral bridged metallocene compound as a catalyst for the polymerization of propylene.

[0051] As a further aspect of the present application, there is provided a catalyst for the polymerization of propylene, which comprises the above-mentioned sulfur-containing chiral bridged metallocene compound.

[0052] As a further aspect of the present application, there is provided a catalytic polymerization reaction of propylene, which uses the above-mentioned sulfur-containing chiral bridged metallocene compound as a catalyst for the polymerization of propylene.

[0053] As a further aspect of the present application, there is provided the use of the above-mentioned sulfur-containing chiral bridged metallocene compound as a catalyst for the polymerization of propylene.

[0054] As a further aspect of the present application, there is provided the use of the above-mentioned sulfur-containing chiral bridged metallocene compound as a catalyst for the polymerization of propylene.

[0055] As a further aspect of the present application, there is provided the use of the above-mentioned sulfur-containing chiral bridged metallocene compound as a catalyst for the polymerization of propylene. DETAILED DESCRIPTION

[0056] The embodiments of the present application will be described in detail below with reference to the following examples; however, it should be understood that the following examples are for illustrative purposes only and should not be construed to limit the scope of the present application. Unless otherwise specified, the conditions in the examples were carried out under conventional conditions or according to the manufacturer's instructions. The reagents or instruments or methods used in the examples of the present application are not specified unless the source is indicated; all are conventional products available on the market or available from the applicant.

[0057] In US 2007 / 0135623 A1, the cyclization of 2-methylthiophene with methacrylic acid is catalyzed by polyphosphoric acid to produce the compound with the structure of general formula (IV) in claim 5. It is found that polyphosphoric acid is highly corrosive and deliquescent. In particular, the organic phase and aqueous phase are not easy to separate during the post-treatment of liquid-liquid extraction, leading to difficult extraction. The use of Eaton's reagent (i.e. 7.7 w% P2O5 in methanesulfonic acid) instead of polyphosphoric acid can well solve the problem of liquid-liquid separation, and the reaction is easier to control and the yield is stable. The selectivity and yield of the subsequent bromination reaction are very high. Further reduction and intramolecular dehydration produce 2,5-dimethyl-3-bromo-cyclopentyl[2,3-b]thiophene with the structure of general formula (VII). US 2007 / 0135623 A1 directly uses 2,5-dimethyl-3-bromo-cyclopentyl[2,3-b]thiophene for silicon bridging and zirconium metal coordination, and does not perform derivatization by C-C coupling reaction at the position of bromine substitution. We found that under conventional C-C coupling conditions, substitution of bromine cannot be achieved, for example, under the catalysis of palladium acetate, diphenylphosphine ferrocene dichloropalladium, palladium tetraphenylphosphine, dichlorobis(triphenylphosphine)palladium, bis(tri-tert-butylphosphine)palladium, nickel acetate, diphenylphosphine ferrocene dichloronickel, nickel tetraphenylphosphine, dichlorobis(triphenylphosphine)nickel, bis(tri-tert-butylphosphine)nickel, etc., no reaction can be performed with aryl boronic acid or aryl Grignard reagent. Through a large number of condition screening, it is found that only under the catalysis of bis(tri-tert-butylphosphine)palladium and in the presence of ZnCl2, the coupling reaction of 2,5-dimethyl-3-bromo-cyclopentyl[2,3-b]thiophene with aryl Grignard reagent with the structure of general formula (VIII) can be achieved. Further, MeSiCl2 can be coupled to produce ligand with the structure of general formula (X). Then, MX4 (M = Ti, Zr, Hf; X = Cl, Br) is reacted to produce the complex with the structure of general formula (I) in claim I.

[0058] In embodiments 1, 2, 3 and 4, [dimethylsil(2,5-dimethyl-3-(4-methoxyphenyl)- cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride, [dimethylsil(2,5-dimethyl-3-(4-tert-butylphenyl)-cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride, [dimethylsil(2,5-dimethyl-3-(4-fluorophenyl)-cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride, [dimethylsil(2,5-dimethyl-3-(2-naphthyl)-cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride and other four new thiophene ring silicon-bridged chiral metallocene zirconium complex compounds are synthesized according to the process route 1, and exhibit excellent catalytic performance in propylene polymerization.

[0059]

[0060] The inventors, through further research and development, formulated this invention. The metallocene catalyst structure provided by this invention preferentially employs a silicon-bridged approach. By substituting an alkyl group at position 2 and an aryl group at position 4 of the bridgehead in the compound ligand, a zirconium metal complex with a C2-symmetric ring-bridged chiral structure containing thiophene was synthesized. The design concept of this invention is that, unlike the indene (benzocyclopentadiene) used as a ligand in general literature, thiophenecyclopentadiene is used as the cyclic structure. Considering that S in the thiophene ring has an electron-donating conjugation effect and relatively soft basicity, it can better coordinate with transition metals. The inventors designed and synthesized a chiral bridged zirconium metal catalyst with thiophene-cyclopentadiene as the ligand. Using Eaton reagent as the ring-closing reagent, the intermediate 2,5-dimethyl-3-bromo-cyclopentyl[2,3-b]thiophene was prepared. Based on this, subsequent coupling, bridging, and Zr metal coordination were carried out to prepare [dimethylsilyl(2,5-dimethyl-3-phenyl-R-cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride. Its synthesis steps are simpler and safer than the original preparation method, which is convenient for large-scale preparation and industrial production.

[0061] A zirconium metal complex with a thiophene ring chiral bridging structure was applied to the catalytic polymerization of polypropylene. The molar ratio of the co-catalyst (MAO) to silica gel and the metallocene complex was 50:33:1, the loading temperature was 40℃, and the catalytic reaction time was 2h. This method can catalyze the production of polypropylene with a high melt index.

[0062] The evaluation and analysis methods used in this invention are as follows: 1 H NMR, 13 C NMR, Fourier transform infrared spectroscopy.

[0063] Example 1: Synthesis of [dimethylsilicon(2,5-dimethyl-3-(4-methoxyphenyl)-cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride

[0064] Step (1): Synthesis of 2,5-dimethyl-cyclopentane[2,3-b]thia-4-one

[0065] At room temperature, 46.31 g (0.47 mol) of 2-methylthiophene and 86.09 g (0.56 mol) of methacrylic acid were mixed in a round-bottom flask and transferred to a constant-pressure dropping funnel. 300 mL of Eaton reagent was added to a three-necked flask, and the liquid from the constant-pressure dropping funnel was added dropwise to the three-necked flask. The reaction system was gradually heated to 60 °C, and the reaction was allowed to proceed for one hour after the addition was complete. Afterward, the reaction system was gradually cooled to room temperature.

[0066] The resulting mixture was poured into 500 ml of ice water mixture, 400 ml of dichloromethane was added while stirring, and the lower organic phase was separated using a 300 ml separatory funnel. The resulting organic phase was washed with 2 L of saturated NaHC03solution and 500 mL of water, and then dried with anhydrous Na2S04. The organic solvent was removed by rotary evaporation to obtain a black oily liquid, and 35.25 g of a light yellow oily liquid was obtained by distillation under reduced pressure, with a yield of 45.10%. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 6.74 (s, 1H), 3.21 (dd, J = 17.2, 6.8 Hz, 1H), 2.95 (pd, J = 7.4, 2.7 Hz, 1H), 2.57 (d, J = 2.7 Hz, 3H), 2.53 (d, J = 2.7 Hz, 1H), 1.33 (d, J = 7.4 Hz, 3H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 199.49, 167.56, 157.13, 137.66, 122.64, 116.72, 46.30, 32.93, 16.85.

[0067] Example 1 Preparation of 2,5-dimethyl-cyclopenta[2,3-b]thi-4-one using polyphosphoric acid

[0068] In a round bottom flask, 46.31 g (0.47 mol) of 2-methylthiophene and 86.09 g (0.56 mol) of methacrylic acid were mixed and transferred to a constant pressure dropping funnel. A solution of polyphosphoric acid (from 400 g P4O10 10 and 280 g of 85% phosphoric acid) was added to a three-necked flask, and the liquid in the constant pressure dropping funnel was added dropwise to the three-necked flask, and the reaction system was gradually warmed to 60 °C. After the addition was completed, the reaction was allowed to proceed for 1.5 hours, and after the reaction was completed, the reaction system was gradually cooled to room temperature. The resulting mixture was poured into 2 L of an ice water mixture, and 1 L of dichloromethane was used to extract the organic phase. The resulting organic phase was neutralized with sodium carbonate, and then washed with 500 L of water. After drying with anhydrous Na2S04, filtration, and rotary evaporation to remove the organic solvent, a black oily liquid was obtained. Distillation under reduced pressure yielded 24.06 g of a light colorless oily liquid, with a yield of 30.8%, which was close to the yield of 31% described in U.S. Patent US 2007 / 0135623 Al.

[0069] Example 2 Preparation of 2,5-dimethyl-cyclopenta[2,3-b]thi-4-one using a mixed solution of sulfuric acid and phosphoric acid

[0070] In a round bottom flask, 46.31 g (0.50 mol) of 2-methylthiophene and 86.09 g (0.59 mol) of methacrylic acid were mixed and transferred to a constant pressure dropping funnel. A three-necked flask was charged with 410 g of 98% concentrated sulfuric acid and 300 g of a mixture of 85% phosphoric acid, and the liquid in the constant pressure dropping funnel was added dropwise into the three-necked flask, and the reaction system was gradually warmed to 60°C. After the dropwise addition was completed, the reaction was allowed to proceed for 1.5 hours, and after the reaction was completed, the reaction system was gradually cooled to room temperature. The resulting mixture was poured into a 2 L ice water mixture, and the organic phase was extracted with 2.5 L dichloromethane. The obtained organic phase was neutralized with sodium carbonate solution, washed with 500 ml of saturated sodium chloride solution, and then dried with anhydrous K2CO3. The organic solvent was removed by rotary evaporation to obtain a black oily liquid, and yellow oily liquid was obtained by distillation under reduced pressure, with a yield of 12.72 g, 15.3%.

[0071] Examples Catalyst composition Yield Example 1 Eaton's reagent 45.1％ Comparative Example 1 Polyphosphoric acid 30.8％ Comparative Example 2 Sulfuric acid, phosphoric acid mixture 15.3％

[0072] It was found by the comparative example that the use of Eaton's reagent catalyzes the reaction of 2-methylthiophene with methacrylic acid to produce fewer byproducts and a higher yield.

[0073] Step (2): Synthesis of 2,5-dimethyl-3-bromo-cyclopenta[2,3-b]thiophene-4-one

[0074] A three-necked flask was charged with 111.06 g (0.83 mol) of aluminum chloride solid and dissolved with 150 ml of chloroform. 61.78 g (0.37 mol) of 2,5-dimethyl-cyclopenta[2,3-b]thiophene-4-one was dissolved in 100 ml of chloroform and added dropwise into the three-necked flask using a 250 ml constant pressure dropping funnel, and the temperature was controlled at 0°C during the dropwise addition. Then 19.06 ml (0.37 mol) of liquid bromine was placed in a 250 ml constant pressure dropping funnel, and 25 ml of chloroform was added. The bromine chloroform solution was added dropwise into the three-necked flask, and the temperature was controlled at 0°C during the dropwise addition. After the dropwise addition was completed, the reaction system was allowed to react at room temperature for 3 hours, and the progress of the reaction was detected by thin layer chromatography. After the reaction was completed, the reaction mixture was poured into an ice water mixture, and the organic phase was washed with dichloromethane. The organic phase was separated and washed with saturated NaHCO3 solution until it was neutral. After drying, the organic solvent was removed by rotary evaporation to obtain a brownish oily liquid, and yellow transparent oily liquid was obtained by distillation under reduced pressure, with a yield of 73.37 g, 80.47%. 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 3.17 (dd, J = 17.4, 6.9 Hz, 1H), 2.98 (td, J = 7.3, 2.6 Hz, 1H), 2.52 (s, 3H), 1.35 (d, J = 7.5 Hz, 3H); 13CNMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 198.49, 166.26, 150.65, 136.19, 108.08, 62.45, 46.01, 32.82, 16.64.

[0075] Step (3): Synthesis of 2,5-dimethyl-3-bromo-cyclopentadienyl[2,3-b]thiophene

[0076] Weigh 27.56 g (112.40 mmol) of 2,5-dimethyl-3-bromo-cyclopent[2,3-b]thiophene-4-one and pour into a 500 ml three-necked flask, add a mixture of tetrahydrofuran: methanol 210 ml, volume ratio 3:1, and 6.67 g (176.50 mmol) of sodium borohydride in 5 portions. Control the temperature at 0°C during the process, and react for 36 h. After the reaction is completed, pour the reaction solution into 80 ml of ice water, and adjust the PH of the solution to PH = 1 with 190 ml of 10% aqueous hydrochloric acid solution. Extract the organic phase with 400 ml of dichloromethane, first wash with 120 ml of saturated Na2CO3 solution, then wash with water until the organic phase is neutral, obtain a black solution, then dry with anhydrous K2SO4, filter, and remove the organic solvent under vacuum to obtain a red-brown liquid. Dissolve the above liquid in 210 ml of toluene, and reflux with 0.34 g (1.93 mmol) of p-toluenesulfonic acid for 15 min. The reaction system changes from red to dark red. Rinse the liquid with a silica gel column, and elute with a mixture of n-hexane and methyl tert-butyl ether (volume ratio 1:1). Remove the organic solvent by rotary evaporation to obtain a red-brown oily liquid 18.62 g, yield 72.28%. 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 6.35 (d, J = 1.6 Hz, 1H), 3.04 (s, 3H), 2.39 (s, 6H), 2.12 (s, 6H); 13 C NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 145.72, 144.81, 140.79, 131.85, 122.12, 105.81, 40.15, 16.94, 15.08.

[0077] Step (4): Synthesis of 2,5-dimethyl-3-(4-methoxyphenyl)-cyclopentadienyl[2,3-b]thiophene

[0078] Into a 500 ml Schlenk flask, 50 ml dry THF was added under nitrogen protection, followed by 35 ml (1 M) zinc chloride solution and 35 ml (1 M) 4-methoxy magnesium bromide solution, the solution became turbid. Stirring at room temperature for 1 h, then 8.02 g (35 mmol) 2,5-dimethyl-3-bromo-cyclopentadienyl[2,3-b]thiophene and 0.36 g (0.70 mmol) bis(tri-tert-butylphosphine)palladium were added to the mixed solution. Heating to 65 °C, monitoring the progress of the reaction by thin layer chromatography. After 10 h, the reaction was completed, filtered, rotary evaporated, extracted with 500 ml petroleum ether, to get light yellow solid 7.98 g, yield 88.96%. mp: 61-62 °C. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.34 (d, J = 8.5 Hz, 2H), 6.96 (d, J = 8.5 Hz, 2H), 6.41 (s, 1H), 3.85 (s, 3H), 3.10 (s, 2H), 2.47 (s, 3H), 2.13 (s, 3H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 158.31, 145.53, 145.11, 140.23, 133.45, 132.55, 129.75, 128.92, 122.01, 113.80, 55.29, 40.38, 16.99, 14.82.

[0079] Step (5): Synthesis of dimethylsilane (2,5-dimethyl-3-(4-methoxy)-phenyl- cyclopentadienyl[2,3-b]thiophene)2

[0080] Into a 500 ml Schlenk flask, 50 ml dry THF was added under nitrogen protection, followed by 35 ml (1 M) zinc chloride solution and 35 ml (1 M) 4-methoxy magnesium bromide solution, the solution became turbid. Stirring at room temperature for 1 h, then 8.02 g (35 mmol) 2,5-dimethyl-3-bromo-cyclopentadienyl[2,3-b]thiophene and 0.36 g (0.70 mmol) bis(tri-tert-butylphosphine)palladium were added to the mixed solution. Heating to 65 °C, monitoring the progress of the reaction by thin layer chromatography. After 10 h, the reaction was completed, filtered, rotary evaporated, extracted with 500 ml petroleum ether, to get light yellow solid 7.98 g, yield 88.96%. mp: 61-62 °C. 1H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.40-7.01 (m, 8H), 6.52 (s, 2H), 3.89 (s, 1H), 2.53 (s, 6H), 2.30 (s, 6H), -0.17 (s, 3H), -0.21 (s, 3H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 158.40, 149.20, 146.59, 136.23, 134.65, 130.38, 130.04, 128.78, 122.85, 113.76, 55.22, 45.90, 17.69, 14.62, -8.07.

[0081] Step (6): Synthesis of [dimethylsil(2,5-dimethyl-3-(4-methoxyphenyl)- cyclopentadienyl[2,3-b]thiophenyl)2]zirconium dichloride

[0082] At -78 °C, 3.8 ml (3 mmol) of n-butyllithium in hexane (1.6 M) was slowly added dropwise to 1.70 g (3 mmol) of dimethylsil(2,5-dimethyl-3-(4-methoxy)- phenyl-cyclopentadienyl[2,3-b]thiophenyl)2 in 100 ml of ether, dropwise with stirring, then stirred at room temperature for 5 h. After the reaction was complete, 0.70 g (3 mmol) of zirconium chloride was added to the system, and the reaction system was stirred at room temperature for 6 h. After the reaction was complete, the reaction solution was filtered, rinsed with ether, the filtrate was collected and dried, and recrystallized from 3 ml of dichloromethane. At the same time, the solid remaining in the funnel was rinsed with dichloromethane, and the mother liquor was dried to obtain a solid 0.73 g, yield 34.59%, elemental analysis C 56.89%, H 5.23%; theoretical value C 56.97%, H 5.31%; 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.44 (d, J = 8 Hz, 4H), 6.98 (d, J = 8 Hz, 4H), 6.58 (s, 2H), 3.83 (s, 6H), 2.52 (s, 6H), 2.32 (s, 6H), 1.06 (s, 6H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 160.72, 148.60, 145.10, 136.22, 131.93, 130.97, 128.70, 126.86, 119.87, 115.77, 85.79, 57.09, 20.84, 16.93, 0.90.

[0083] The chiral bridged metallocene compound prepared in this example is shown in formula (I), wherein R1 is 4-methoxyphenyl;

[0084] R2 is methyl; R3 is methyl; M is zirconium; and X is chlorine.

[0085] Example 2: Synthesis of [dimethylsil(2,5-dimethyl-3-(4-tert-butylphenyl)- cyclopentadienyl[2,3-b]thiophenyl)2]zirconium dichloride

[0086] Step (1): Synthesis of 2,5-dimethyl-cyclopenta[2,3-b]thi-4-one

[0087] At room temperature, 44.34 g (0.45 mol) of 2-methylthiophene and 77.48 g (0.50 mol) of methacrylic acid were mixed in a round-bottom flask and transferred to a constant-pressure dropping funnel. 300 ml of Eaton's reagent was added to a three-neck flask, and the liquid in the constant-pressure dropping funnel was added dropwise to the three-neck flask, and the reaction system was gradually heated to 80°C. After the addition was completed, the reaction was allowed to proceed for 3 hours, and then the reaction system was gradually cooled to room temperature.

[0088] The resulting mixture was poured into a 500 ml ice-water mixture, 400 ml of dichloromethane was added while stirring, and the liquid was separated using a 300 ml separatory funnel, and the lower organic phase was removed. The resulting organic phase was washed with 3 L of saturated NaHCO3 solution and water, and then dried with anhydrous Na2SO4. The organic solvent was removed by rotary evaporation to obtain a black oily liquid, and 35.25 g of a light yellow oily liquid was obtained by distillation under reduced pressure, with a yield of 37.2%. 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 6.74 (s, 1H), 3.21 (dd, J = 17.2, 6.8 Hz, 1H), 2.95 (pd, J = 7.4, 2.7 Hz, 1H), 2.57 (d, J = 2.7 Hz, 3H), 2.53 (d, J = 2.7 Hz, 1H), 1.33 (d, J = 7.4 Hz, 3H).

[0089] Step (2): Synthesis of 2,5-dimethyl-3-bromo-cyclopenta[2,3-b]thiophen-4-one

[0090] A 28.4 g (0.213 mol) of aluminum chloride solid was weighed and dissolved in 100 ml of chloroform and added to a 500 ml three-necked flask. 15.77 g (0.095 mol) of 2,5-dimethyl-cyclopenta[2,3-b]thiophene-4-one was dissolved in 50 ml of chloroform and added dropwise to the three-necked flask using a 250 ml constant pressure dropping funnel, and the temperature was controlled at 0-5°C during the dropwise addition. Then 5.35 ml (0.104 mol) of liquid bromine was placed in a 250 ml constant pressure dropping funnel, and 20 ml of chloroform was added. The bromine chloroform solution was added dropwise to the three-necked flask, and the temperature was controlled at 0°C during the dropwise addition. After the dropwise addition was completed, the reaction system was allowed to react at room temperature for 1.5 h, and the reaction progress was detected by thin layer chromatography. After the reaction was completed, the reaction mixture was poured into an ice water mixture, and washed with dichloromethane. The organic phase was separated and washed with saturated NaHCO3 solution until it was neutral. After drying, the organic solvent was removed by rotary evaporation to obtain a brownish oil liquid. Distillation under reduced pressure yielded 17.16 g of yellow transparent oil, with a yield of 73.71%. 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 3.17 (dd, J = 17.4, 6.9 Hz, 1H), 2.98 (td, J = 7.3, 2.6 Hz, 1H), 2.52 (s, 3H), 1.35 (d, J = 7.5 Hz, 3H).

[0091] Step (3): Synthesis of 2,5-dimethyl-3-bromo-cyclopentadienyl[2,3-b]thiophene

[0092] A 24.52 g (100.0 mmol) of 2,5-dimethyl-3-bromo-cyclopenta[2,3-b]thiophene-4-one was weighed and poured into a 500 ml three-necked flask, and a 200 ml tetrahydrofuran:methanol mixture (1:1 by volume) was added, and 5.93 g (157.03 mmol) of sodium borohydride was added in five portions, and the temperature was controlled at 0°C during the addition, and the reaction was allowed to proceed for 24 h. After the reaction was completed, the reaction solution was poured into 100 ml of ice water, and the pH of the solution was adjusted to 1 with 10% hydrochloric acid aqueous solution. The organic phase was extracted with 500 ml of dichloromethane, and then washed with saturated Na2CO3 solution, and then washed with water until the organic phase was neutral, and a black solution was obtained, which was then dried with anhydrous K2SO4, filtered, and the organic solvent was removed by vacuum evaporation to obtain a red-brown liquid. The liquid was dissolved in 180 ml of toluene, and 0.25 g (1.43 mmol) of p-toluenesulfonic acid was added, and refluxed for 15 min, and the reaction system changed from red to dark red. The liquid was washed with a silica gel column, and the eluent was a mixture of n-hexane and methyl tert-butyl ether (1:1 by volume), and the organic solvent was removed by rotary evaporation to obtain a red-brown oil liquid 16.34 g, with a yield of 71.30%. 1H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 6.35 (d, J = 1.6 Hz, 1H), 3.04 (s, 3H), 2.39 (s, 6H), 2.12 (s, 6H).

[0093] Step (4): Synthesis of 2,5-dimethyl-3-(4-tert-butyl-phenyl)-cyclopenta- dienyl[2,3-b]thiophene

[0094] Into a 500 ml Schlenk flask under nitrogen was added 50 ml of dry tetrahydrofuran solution, followed by 35 ml of 1 M zinc chloride solution and 35 ml of 1 M 4-tert-butyl magnesium bromide solution, the solution became turbid. Stirring at room temperature for 2 h, then 8.02 g (35 mmol) of 2,5-dimethyl-3-bromo-cyclopenta-dienyl[2,3-b]thiophene and 0.36 g (0.70 mmol) of bis(tri-tert-butylphosphine)palladium were added to the mixed solution in turn. Heating to 80 °C, monitoring the progress of the reaction by thin layer chromatography. After 4 h, the reaction was completed, filtered, dried, extracted with 500 ml of hot petroleum ether to obtain a light yellow solid 4.21 g, yield 42.60%. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.34 (d, J = 8.4 Hz, 2H), 7.25 (d, J = 8.4 Hz, 2H), 6.31 (s, 1H), 3.04 (s, 2H), 2.40 (s, 3H), 2.03 (s, 3H), 1.27 (s, 9H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 148.30, 144.50, 143.99, 139.20, 132.60, 132.43, 131.89, 127.57, 127.21, 125.59, 124.18, 122.36, 120.92, 39.46, 38.47, 33.50, 30.33, 15.90, 13.86.

[0095] Step (5): Synthesis of dimethylsilanediyl-bis(2,5-dimethyl-3-(4-tert-butyl- phenyl)-cyclopenta-dienyl[2,3-b]thiopheneate)

[0096] To a solution of 5.08 g (20 mmol) of 2,5-dimethyl-3-(4-tert-butylphenyl)- cyclopentadienyl[2,3-b]thiophene in 40 ml of tetrahydrofuran at -78 °C, 8 ml (20 mmol) of n-butyllithium in hexane (2.5 M) was slowly added dropwise with stirring, then it was raised to 20 °C and stirred overnight. After the reaction was completed, the system was cooled to -78 °C again, and 1.08 ml (10 mmol) of dichlorodimethylsilane was added dropwise to the reaction solution. After the addition was completed, the system was raised to 20 °C and stirred overnight. After the reaction was completed, 50 ml of water was added, and the organic layer was extracted with dichloromethane, then dried with anhydrous Mg2SO4, filtered, and column chromatographed with petroleum ether to obtain 3.20 g of yellow solid, with a yield of 56.5%. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.74-7.64 (m, 8H), 6.81 (s, 2H), 4.08 (s, 2H), 2.79 (s, 6H), 2.53 (s, 6H), 1.64 (s, 18H), 0.02 (d, J = 20 Hz, 6H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 149.43, 149.25, 146.29, 136.35, 135.22, 133.50, 130.44, 128.70, 126.69, 125.28, 123.22, 46.11, 34.61, 31.46, 18.06, 15.00, -7.31, -8.52.

[0097] Step (6): Synthesis of [dimethylsil(2,5-dimethyl-3-(4-tert-butylphenyl)- cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride

[0098] To a solution of 1.82 g (3 mmol) of dimethylsil(2,5-dimethyl-3-(4-tert-butyl)- phenyl-cyclopentadienyl[2,3-b]thiophene) in 2100 ml of ether at -78 °C, 3.8 ml (3 mmol) of n-butyllithium in hexane (1.6 M) was slowly added dropwise with stirring, then it was stirred at room temperature for 12 h. After the reaction was completed, 0.70 g (3 mmol) of zirconium chloride was added to the system, and the reaction system was stirred at room temperature for 6 h. After the reaction was completed, the reaction solution was filtered, rinsed with ether, the filtrate was collected and dried, and 3 ml of dichloromethane was recrystallized. At the same time, the solid remaining in the funnel was rinsed with dichloromethane, and the mother liquor was dried to obtain 0.76 g of product, with a yield of 34.54%, and elemental analysis C 62.11%, H 6.44%; theoretical value C 62.19%, H 6.46%; 1H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.42-7.49 (m, 8H), 6.59 (s, 2H), 2.55 (s, 6H), 2.31 (s, 6H), 1.34 (s, 18H), 1.07 (s, 6H); 13 C NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 151.18, 147.65, 144.76, 135.34, 132.47, 130.27, 129.47, 126.45, 126.02, 119.08, 84.91, 35.45, 31.99, 19.94, 16.12, 0.00.

[0099] The chiral bridged metallocene compound prepared in this example is represented by formula (1), wherein R1 is 4-tert-butylphenyl;

[0100] R2 is methyl; R3 is methyl; M is zirconium; and X is chlorine.

[0101] Example 3: Synthesis of [dimethylsil(2,5-dimethyl-3-(4-fluorophenyl)- cyclopentadienyl[2,3-b]thiophenyl)2]zirconium dichloride:

[0102] Steps (1) to (3) are the same as in Example 1 to obtain the intermediate 2,5-dimethyl-3- bromo-cyclopentadienyl[2,3-b]thiophene.

[0103] Step (4): Synthesis of 2,5-dimethyl-3-(4-fluorophenyl)-cyclopentadienyl[2,3-b]thiophene

[0104] Into a 500 ml Schlenk flask under nitrogen protection was added 50 ml dry tetrahydrofuran solution, then 35 ml (1 M) zinc chloride solution and 35 ml (1 M) 4-fluorophenyl magnesium bromide solution, the solution became turbid, stirred at room temperature for 1 h, then 8.02 g (35 mmol) 2,5-dimethyl-3-bromo-cyclopentadienyl[2,3-b]thiophene and 0.36 g (0.70 mmol) bis(tri-tert-butylphosphine)palladium were added to the mixed solution. Heated to 65 °C, the progress of the reaction was monitored by thin layer chromatography. The reaction was completed after 10 h, filtered, rotary evaporated, extracted with 500 ml petroleum ether, to obtain light green solid 6.69 g, yield 78.40%. mp: 80-81 °C. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.41-7.11 (m, 4H, Ar-H), 6.44 (s, 1H), 3.12 (s, 2H), 2.49 (s, 3H), 2.16 (s, 3H); 13C NMR (101 MHz, CDC13) δ 194.77, 192.94, 140.56, 132.46, 130.17, 122.02, 115.42, 115.21, 40.28, 16.96, 14.72.

[0105] Step (5): Synthesis of dimethylsilane (2,5-dimethyl-3-(4-fluorophenyl)- cyclopentadienyl[2,3-b]thiophene)2

[0106] To a solution of 4.89 g (20 mmol) of 2,5-dimethyl-3-(4-fluorophenyl)- cyclopentadienyl[2,3-b]thiophene in 40 ml of tetrahydrofuran, 8 ml (20 mmol) of n-butyllithium in hexane (2.5 M) was slowly added dropwise with stirring at -78°C, then raised to 20°C, and stirred overnight. After the reaction was completed, the system was cooled to -78°C again, and 0.97 ml (10 mmol) of dichlorodimethylsilane was added dropwise to the reaction solution, after the addition was completed, the system was raised to 20°C, and stirred for 24 h, 50 ml of water was added, the organic layer was extracted with dichloromethane, then dried with anhydrous Mg2SO4, filtered, the organic solvent was removed in vacuum, recrystallized with diethyl ether at room temperature to obtain 1.62 g of product, yield 29.78%. 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 7.44-7.41 (m, 8H), 6.49 (s, 2H), 3.93 (s, 1H), 3.80 (s, 1H), 2.53 (d, J = 4.0 Hz, 6H), 2.29 (s, 3H), 2.18 (s, 3H)-0.17 (s, 3H), -0.20 (s, 3H); 13 C NMR (CDC13, 25°C, TMS): δ (ppm) 162.87, 160.43, 146.69, 136.50, 135.49, 130.61, 130.53, 122.80, 122.72, 115.38, 115.17, 46.18, 46.96, 18.01, 17.92, 12.79, 14.75, -7.67.

[0107] Step (6): Synthesis of [dimethylsilane (2,5-dimethyl-3-(4-fluorophenyl)- cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride

[0108] To a solution of 1.50 g (3 mmol) of dimethylsilanediyl(2,5-dimethyl-3-(4- fluorophenyl)-cyclopentadienyl[2,3-b]thiophene)2in 100 mL of diethyl ether at -78 °C, 3.8 mL (3 mmol) of n-butyllithium in hexane (1.6 M) was added dropwise with stirring using a syringe, and then stirred at room temperature for 5 h. After the reaction was completed, 0.70 g (3 mmol) of zirconium chloride was added to the system, and the reaction system was stirred at room temperature for two days. After the reaction was completed, the reaction solution was filtered, rinsed with diethyl ether, the filtrate was collected and dried, and 3 mL of dichloromethane was used for recrystallization. At the same time, the solid remaining in the funnel was rinsed with dichloromethane to obtain 0.23 g of the product, elemental analysis C 55.46%, H 4.65%; theoretical value C 55.56%, H 4.66%. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.50 - 7.12 (m, 8H), 6.57 (s, 2H), 2.54 (s, 6H), 2.34 (s, 6H), 1.09 (s, 18H), 1.23 (s, 6H); 13 C NMR (101 MHz, CDC13) δ 146.88, 144.26, 134.36, 133.00, 130.70, 128.80, 125.00, 117.84, 115.47, 83.94, 65.86, 19.17, 15.22.

[0109] The chiral bridged metallocene compound containing sulfur prepared in this example is shown in formula (1), wherein R1is p-4-fluorophenyl;

[0110] R2is methyl; R3is methyl; M is zirconium; and X is chlorine.

[0111] Example 4: Synthesis of [dimethylsilanediyl(2,5-dimethyl-3-(2-naphthyl)- cyclopentadienyl[2,3-b]thiophene)2]zirconium dichloride:

[0112] Steps (1) to (3) are the same as in Example 1 to obtain the intermediate 2,5-dimethyl- 3-bromo-cyclopentadienyl[2,3-b]thiophene.

[0113] Step (4): Synthesis of 2,5-dimethyl-3-(2-naphthyl)-cyclopentadienyl[2,3-b]thiophene)2

[0114] Into a 500 ml Schlenk flask under nitrogen, 50 ml of dry tetrahydrofuran was added, followed by 24 ml (1 M) of zinc chloride solution and 47 ml (23.5 M) of 2-naphthyl magnesium bromide solution, the solution became turbid, and was stirred at room temperature for 1 h, then 5.27 g (23.5 mmol) of compound 4 and 0.24 g (0.47 mmol) of bis(triphenylphosphine) palladium were added to the mixed solution. It was heated to 65 °C, and the progress of the reaction was monitored by thin layer chromatography. After 10 h, the reaction was completed, filtered, dried, and extracted with 1000 ml of hot petroleum ether to obtain a light yellow solid 3.24 g, yield 35.40%. mp: 85-87 °C. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.94-7.52 (m, 7H, Ar-H), 6.48 (s, 1H), 3.20 (s, 2H), 2.58 (s, 3H), 2.18 (s, 3H); 13 C NMR (101 MHz, CDC13) δ 145.60, 145.28, 127.91, 127.71, 127.36, 127.12, 126.16, 125.80, 122.04, 40.45, 16.99, 14.89.

[0115] Step (5): Synthesis of dimethylsilane (2,5-dimethyl-3-(2-naphthyl)- cyclopentadienyl[2,3-b]thiophene)2

[0116] At -78 °C, 8 ml (20 mmol) of n-butyllithium hexane solution (2.5 M) was slowly added to 5.33 g (20 mmol) of 2,5-dimethyl-3-(2-naphthyl)- cyclopentadienyl[2,3-b]thiophene in 40 ml of tetrahydrofuran solution with stirring, then raised to 25 °C, stirred for 3 h, the system was cooled to -78 °C again, 0.97 ml (10 mmol) of dichlorodimethylsilane was added dropwise to the reaction solution, after the addition was completed, the system was raised to 20 °C and stirred overnight, after the reaction was completed, 50 ml of water was added, the organic layer was extracted with dichloromethane, then dried with anhydrous Mg2S04, filtered, and the organic solvent was removed under vacuum, and recrystallized with ether at room temperature to obtain the product 3.72 g, yield 30.5%. 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 8.02-7.45 (m, 14H, Ar-H(o)), 6.49 (s, 2H), 2.57 (d, J = 4.0 Hz, 6H), 2.19 (s, 3H), 2.18 (s, 3H), -0.17 (s, 3H), -0.20 (s, 3H); 13C NMR (101 MHz, CDC13) δ 164.19, 160.34, 149.52, 140.56, 136.67, 135.93, 134.02, 133.58, 132.22, 126.18, 125.78, 123.03, 46.28, 18.12, 14.99.

[0117] Step (6): Synthesis of [dimethylsil(2,5-dimethyl-3-(2-naphthyl)- cyclopentadienyl[2,3-b]thiophenyl)2]zirconium dichloride

[0118] 1.82 g (3.0 mmol) of dimethylsil(2,5-dimethyl-3-(2-naphthyl)- cyclopentadienyl[2,3-b]thiophenyl)2 was placed in a 200 ml Schlenk flask, which was vacuumed and 100 ml of anhydrous diethyl ether was added. Subsequently, 2.4 ml (2.5 M) of n-butyllithium in n-hexane was added under alcohol-liquid nitrogen bath conditions, and stirred for 5 hours. Then, 0.70 g (3 mmol) of zirconium tetrachloride was added to the Schlenk flask under anhydrous and anaerobic conditions, and stirred for 3 hours. After standing, the filter cake was washed with 15 ml of anhydrous diethyl ether, and then further filtered. The two filtrates were combined and concentrated. The filter cake was dissolved in 50 ml of dichloromethane, filtered, and the obtained filtrate was dried to obtain 0.39 g of a dark green solid, with a yield of 17%, and elemental analysis C 62.27%, H 4.95%; theoretical value C 63.13%, H 5.05%; 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.94-7.46 (m, 14H, Ar-H(o)), 6.66 (s, 2H, C=C-H), 2.60 (s, 6H, C=C-C-H), 2.36 (s, 6H,, C=C-C-H), 1.09 (s, 6H, Si-C-H); 13 C NMR (101 MHz, CDC13) δ 164.19, 160.34, 149.52, 140.56, 136.67, 135.93, 134.02, 133.58, 132.22, 126.18, 125.78, 123.03, 46.28, 18.12, 14.99; 13 C NMR (101 MHz, CDC13) δ 134.33, 133.46, 132.59, 129.81, 128.22, 127.66, 127.07, 126.06, 125.98, 118.14, 19.24, 15.43.

[0119] The chiral bridged metallocene compound prepared in this example is represented by formula (1), wherein R1 is p-2-naphthyl;

[0120] R2 is methyl; R3 is methyl; M is zirconium; X is chlorine.

[0121] Example 5 [dimethylsilicon(2,5-dimethyl-3-(4-methoxyphenyl)- cyclopentadienyl[2,3-b]thiophene)2]hafnium dibromide

[0122] A solution of 3.8 ml (3 mmol) n-butyllithium in hexane (1.6 M) was slowly added dropwise to a solution of 1.70 g (3 mmol) dimethylsilicon(2,5-dimethyl-3-(4- methoxyphenyl)-cyclopentadienyl[2,3-b]thiophene) in 100 ml diethyl ether at -78°C, dropwise with stirring, and then stirred at room temperature for 12 h. After the reaction was completed, 1.49 g (3 mmol) hafnium bromide was added to the system, and the reaction system was stirred at room temperature for 12 h. After the reaction was completed, the reaction solution was filtered, rinsed with diethyl ether, the filtrate was collected and dried, and 3 ml dichloromethane was recrystallized. At the same time, the solid remaining in the funnel was rinsed with dichloromethane, the mother liquor was dried, and 0.17 g of product was obtained, with a yield of 6.55%, and elemental analysis C 46.35%, H 4.11%; theoretical value C 46.23%, H 4.31%; 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 7.42 (d, J = 8 Hz, 4H), 6.97 (d, J = 8 Hz, 4H), 6.56 (s, 2H), 3.81 (s, 6H), 2.51 (s, 6H), 2.31 (s, 6H), 1.04 (s, 6H); 13 C NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 160.71, 148.60, 145.08, 136.22, 131.90, 130.96, 128.70, 126.85, 119.87, 115.75, 85.76, 57.08, 20.84, 16.90, 0.89.

[0123] The chiral bridged metallocene compound prepared in this example is shown in formula (I), wherein R1 is 4-methoxyphenyl;

[0124] R2 is methyl; R3 is methyl; M is hafnium; X is bromine.

[0125] Example 6 Synthesis of [dimethylsilicon(2-isopropyl-5-methyl-3-(4-tert-butyl)- phenyl-cyclopentadienyl[2,3-b]thiophene)2] titanium dichloride

[0126] To a solution of 1.82 g (3 mmol) of dimethylsilicon (2-isopropyl-5-methyl-3-(4-tert-butyl)-phenyl-cyclopentadienyl[2,3-b]thiophene)2in 100 ml of diethyl ether at -78°C, 3.8 ml (3 mmol) of n-butyllithium in hexane (1.6 M) was slowly added dropwise with a syringe, dropwise with stirring, and then stirred at room temperature for 6 h. After the reaction was complete, 0.33 ml (3 mmol) of titanium tetrachloride was added to the system, and the reaction system was stirred at room temperature for 5 h. After the reaction was complete, the reaction solution was filtered, rinsed with diethyl ether, the filtrate was collected and dried, recrystallized from 3 ml of dichloromethane, and 0.31 g of a solid was obtained, with a yield of 15.77%, and elemental analysis C 67.11%, H 7.52%; theoretical value C 67.06%, H 7.34%; 1 H NMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 7.44-7.51 (m, 8H), 6.59 (s, 2H), 2.53 (s, 6H), 2.30 (s, 12H), 1.34 (s, 18H), 1.06 (s, 6H); 13 CNMR (400 MHz, CDC13, 25°C, TMS): δ (ppm) 151.18, 147.65, 144.77, 135.33, 132.46, 130.27, 129.48, 126.44, 126.05, 119.10, 84.92, 35.44, 31.94, 19.93, 16.12, 0.00.

[0127] The sulfur-containing chiral bridged metallocene compound prepared in this example is shown in formula (1), wherein R1is 4-tert-butylphenyl;

[0128] R2is methyl; R3is isopropyl; M is titanium; and X is chlorine.

[0129] Example 7 Synthesis of [dimethylsilicon (2,5-dimethyl-3-(4-fluorophenyl)- cyclopentadienyl[2,3-b]thiophene)2]zirconium difluoride

[0130] To a solution of 1.50 g (3 mmol) of dimethylsilane (2,5-dimethyl-3-(4- fluorophenyl)-cyclopentadienyl[2,3-b]thiophene) 2 in 100 ml of diethyl ether, 3.8 ml (3 mmol) of n-butyllithium in hexane (1.6 M) was slowly added dropwise with stirring at -78°C, and then stirred at room temperature for 5 h. After completion of the reaction, 0.50 g (3 mmol) of zirconium fluoride was added to the system, and the reaction system was stirred at room temperature for two days. After completion of the reaction, the reaction solution was filtered, rinsed with diethyl ether, the filtrate was collected and dried, 3 ml of dichloromethane was added, and recrystallization was performed. At the same time, the solid remaining in the funnel was rinsed with dichloromethane to obtain 0.15 g of the product with a yield of 7.14%, elemental analysis C 58.21%, H 4.89%; theoretical value C 58.17%, H 4.88%; 1 H NMR (400 MHz, CDC13, 25 °C, TMS): δ (ppm) 7.50-7.12 (m, 8H), 6.56 (s, 2H), 2.51 (s, 6H), 2.34 (s, 6H), 1.07 (s, 18H), 1.21 (s, 6H); 13 C NMR (101 MHz, CDC13) δ 146.89, 144.26, 134.35, 133.03, 130.72, 128.81, 125.00, 117.85, 115.47, 83.94, 65.86, 19.15, 15.20.

[0131] The chiral bridged metallocene compound prepared in this example is shown in formula (1), wherein R1 is p-4-fluorophenyl; R2 is methyl; R3 is methyl; M is zirconium; and X is fluorine.

[0132] Loading of metallocene compounds in Examples 8-14

[0133] 1 g of silica and 1 g of methylaluminoxane (MAO) solid powder were dissolved in 30 ml of anhydrous toluene, and the reaction was stirred at 100°C for 5 h. After precipitation, the supernatant was removed, and the precipitate was washed twice with toluene. 110 mg of a metallocene compound (4-methoxyphenyl-zirconium dichloride in Example 1, 4-tert-butylphenyl-zirconium dichloride in Example 2, 4-fluorophenyl-zirconium dichloride in Example 3, 2-naphthyl-4-methoxy in Example 4, 4-methoxy-hafnium dibromide in Example 5, 4-tert-butyl-titanium dichloride in Example 6, and 4-fluorophenyl-zirconium difluoride in Example 7) was dissolved in 10 ml of anhydrous toluene, and the reaction was stirred at 40°C for 5 h. After completion of the reaction, the precipitate was allowed to settle, the supernatant was removed, and the precipitate was washed twice with toluene and twice with hexane, and vacuum dried to obtain a supported catalyst, which was designated as Cat-1, Cat-2, Cat-3, Cat-4, Cat-5, Cat-6, and Cat-7.

[0134] Example 15-21 Propylene polymerization

[0135] In the glove box, the supported metallocene catalyst was placed in a finger tube, 100 mg of filler per tube, and then a 5 L polymerization kettle was preheated, first heated to 70°C, and then reduced to room temperature. At the same time, the reaction kettle was kept under vacuum for 3 h. After vacuuming, the propylene was then charged to atmospheric pressure, 500 ml of hexane was added as a solvent, 2 ml of triethylaluminum was added under stirring, and the catalyst was added after 10 minutes. After 10 minutes of prepolymerization, heating was started, the polymerization temperature was 70°C, the polymerization time was 1 h, and the reaction was stopped after the polymerization was completed. The polymer was taken out, washed, dried and weighed.

[0136]

[0137] From the comparative examples 1-4, it can be seen that when the substituent phenyl group is tert-butyl phenyl, the supported catalyst metal content of the metallocene catalyst containing a thiophene ring structure is closest to 3%, and the catalytic activity is the highest, the melt index of the prepared polypropylene is high, and the flowability is good. From the comparison of comparative example 4 and example 6, it can be seen that when titanium is used as the catalytic active center of the catalyst, the catalytic effect is not as good as when zirconium is used as the catalytic active center. From the comparison of comparative example 3 and example 7, due to the extremely strong electron-withdrawing ability of fluorine, the carrier loading of the catalyst shown in example 7 is extremely low, and the catalyst activity is much lower than that of example 3. In summary, among the several metallocene catalysts containing a thiophene ring structure shown in the present application, when the substituent phenyl group is tert-butyl phenyl and the coordination metal is Zr, the catalyst has high activity, the carrier loading of the catalyst metal is high, and the melt index of the prepared polypropylene is the largest.

[0138] The above examples are only the preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation made by the person skilled in the art on the basis of the present application is within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A chiral bridged metallocene compound containing sulfur, characterized by, The sulfur-containing chiral bridged metallocene compound is a compound as shown in general formula (I): (I) wherein, R1 is 2-naphthyl; R2 and R3 are methyl; M is Zr; X is chlorine.

2. Process for the preparation of the sulphur-containing chiral bridged metallocene compound according to claim 1, characterized in that, Comprise: (1) under the condition of 60-80℃ and Eaton reagent catalysis, the thiofuran compound as shown in general formula (II) is reacted with the acrylic compound as shown in general formula (III) according to equation one, to obtain the compound as shown in general formula (IV); (II) (III) (IV) wherein, R2 and R3 are methyl; (2) according to equation two, aluminum chloride and the compound as shown in general formula (IV) are dissolved in a polar solvent respectively, and a brominating agent is added, and the reaction obtains the compound as shown in general formula (V); (IV) (V) wherein, R2 and R3 are methyl; (3) according to equation three, the compound as shown in general formula (V) is dissolved in a polar solvent, a reducing agent is added to carry out a reduction reaction, to obtain the compound as shown in general formula (VI), the compound as shown in general formula (VI) is dissolved in a benzene solvent, an organic acid catalyst is added, and the compound as shown in general formula (VI) is subjected to intramolecular dehydration reaction to obtain the compound as shown in general formula (VII); (V) (VI) (VII) wherein, R2 and R3 are methyl; (4) The halogenated zinc is added to the anhydrous solvent, and the aryl Grignard reagent as shown in the general formula (VIII) is added under the nitrogen atmosphere; the compound as shown in the general formula (VII) is added, stirred, the catalyst is added, and the reaction is carried out under the condition of 60~80 o C to obtain the ligand precursor as shown in the general formula (IX); (VII) (VIII) (IX) wherein, R1 is 2-naphthyl; R2 and R3 are methyl; (5) according to equation five, the compound as shown in general formula (IX) is added to anhydrous ether solvent, under the condition of alcohol liquid nitrogen bath and nitrogen protection, n-butyl lithium is added, dichlorodimethylsilane is added under low temperature condition, and the reaction obtains the ligand as shown in general formula (X); (IX) (X) wherein, R1 is 2-naphthyl; R2 and R3 are methyl; (6) according to equation six, the ligand as shown in general formula (IX) is added to ether solvent, n-butyl lithium reagent is added under low temperature condition; metal halide MX4 is added under low temperature condition, and the target compound as shown in general formula (I) is obtained by reaction at room temperature; (X) (I) wherein, R1 is 2-naphthyl; R2 and R3 are methyl; M is Zr; X is chlorine.

3. The method of claim 2, wherein, The reaction temperature of step (1) is 80℃, and the reaction time is 1h.

4. The method of claim 2, wherein, In step (2), the polar solvent is chloroform, the brominating agent is liquid bromine, and the molar ratio of the compound as shown in general formula (IV) to the brominating agent is 1:1.

1.

5. The method of claim 2, wherein, In step (3), the polar solvent is a mixed solution of alcohol solvent and ether solvent; the alcohol solvent is any one or more of methanol, ethanol and butanol, the ether solvent is any one or more of diethyl ether, methyl tert-butyl ether and tetrahydrofuran, the volume ratio of the ether solvent to the alcohol solvent is 1-3:1; the reducing agent is one of sodium borohydride, lithium aluminum hydride, potassium borohydride and sodium cyanoborohydride.

6. The method of claim 2 wherein, In step (3), the organic acid is one or more of p-toluenesulfonic acid, formic acid, and acetic acid, the compound of general formula (VI) is subjected to intramolecular dehydration to obtain the compound of general formula (VII), one or more of toluene, benzene, xylene, mesitylene, and chlorobenzene is used as the reaction solvent, the molar ratio of the compound of general formula (VI) to the organic acid is 70:1, and the reaction time is 15 min.

7. The method of claim 2, wherein, In step (4), the aryl Grignard reagent as shown in general formula (VIII) is one of 4-methoxyphenyl magnesium bromide, 4-tert-butylphenyl magnesium bromide, 4-fluorophenyl magnesium bromide, and 2-naphthyl magnesium bromide, the halogenated zinc is zinc chloride, the catalyst is one of palladium acetate, diphenylphosphin ferrocene dichloropalladium, palladium tetra-triphenylphosphine, dichlorobis-triphenylphosphine palladium, and bis(tri-tert-butylphosphine) palladium, the molar ratio of the catalyst to the compound of general formula (VII) is 0.23:1, the reaction temperature is specifically 80°C, and the anhydrous solvent is any one or more of tetrahydrofuran, diethyl ether, and toluene.

8. The method of claim 7, wherein, The catalyst is one of bis(tri-tert-butylphosphine) palladium, nickel acetate, diphenylphosphin ferrocene dichloronickel, nickel tetra-triphenylphosphine, dichlorobis-triphenylphosphine nickel, and bis(tri-tert-butylphosphine) nickel.

9. The method of claim 8, wherein, The catalyst is bis(tri-tert-butylphosphine) palladium.

10. The method of claim 2 wherein, In step (5), the anhydrous ether solution is a tetrahydrofuran solution, and the reaction time is specifically 16 h.

11. The method of claim 2, wherein, In step (6), the ether solvent is diethyl ether, and the molar ratio of n-butyllithium, the compound of general formula (IX), and the metal halide is 2:2:1, wherein M is zirconium and X is chlorine.

12. Use of the chiral bridged metallocene compound containing sulfur according to claim 1 as a catalyst for propylene polymerization.

13. A catalyst for the polymerization of propylene, characterized in that, The catalyst comprises the chiral bridged metallocene compound containing sulfur according to claim 1.

14. A catalytic polymerization of polypropylene, characterized in that, The chiral bridged metallocene compound containing sulfur according to claim 1 is used as a catalyst for propylene polymerization.

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