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CN-121991137-A - Chiral bridged metallocene compound and preparation method and application thereof

CN121991137ACN 121991137 ACN121991137 ACN 121991137ACN-121991137-A

Abstract

The invention discloses a chiral bridged metallocene compound, a preparation method and application thereof, which are characterized in that the chiral bridged metallocene compound is a compound with a general formula (I): Wherein R 1 is selected from 4-substituted phenyl, R 2 is selected from alkyl, M is selected from one of Ti, zr and Hf, and X is selected from halogen. The catalyst prepared by the chiral bridged metallocene compound has better catalytic activity, improves the melt index and isotacticity of the synthesized polypropylene, and can obtain a polypropylene material with better fluidity.

Inventors

  • LEI JUNYU
  • ZHANG YANFANG
  • ZHANG WEI
  • LIN LONG
  • WANG KEFENG
  • CHEN SHANGTAO
  • ZHANG MINGGE
  • YI JIANJUN
  • HAO HAIJUN
  • JIA YUSEN

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. A chiral bridged metallocene compound characterized by a compound having the general formula (I): Wherein, the R 1 is selected from 4-substituted phenyl; R 2 is selected from alkyl; m is selected from one of Ti, zr and Hf; X is selected from halogen.
  2. 2. A process for the preparation of a chiral bridged metallocene compound comprising: (1) Reacting an indenone compound shown in a general formula (II) with a boric acid compound shown in a general formula (III) under the action of a catalyst according to a formula I to obtain a compound shown in a general formula (IV); Wherein R 1 is selected from 4-substituted phenyl and R 2 is selected from alkyl; (2) According to the second equation, firstly, dissolving a compound shown in a general formula (IV) in a polar solvent by using a reducing reagent, then adding the reducing reagent for reduction reaction to obtain an alcohol compound, then adding the alcohol compound into an aromatic solvent, and carrying out dehydration reaction under the catalysis of an organic acid to obtain the compound shown in the general formula (V); Wherein R 1 is selected from 4-substituted phenyl and R 2 is selected from alkyl; (3) According to the third formula, dissolving a compound shown in a general formula (V) in an anhydrous solvent in a nitrogen atmosphere, adding a reducing reagent for reduction reaction to obtain a lithium salt compound shown in a general formula (VI), and reacting the compound shown in the general formula (VI) with dimethyldichlorosilane to obtain a ligand precursor shown in a general formula (VII); Wherein R 1 is selected from 4-substituted phenyl and R 2 is selected from alkyl; (4) According to the fourth formula, dissolving a ligand precursor shown in a general formula (VII) in an anhydrous polar solvent under a nitrogen atmosphere, adding a reducing reagent for reduction reaction to obtain a lithium salt compound shown in a general formula (VIII), and reacting the lithium salt compound shown in the general formula (VIII) with a metal halide to obtain a chiral bridged metallocene compound shown in a general formula (IX); Wherein: R 1 is selected from 4-substituted phenyl; R 2 is selected from alkyl; m is selected from one of titanium, zirconium and hafnium; X is selected from halogen.
  3. 3. The chiral bridged metallocene compound according to claim 1 or the production method of claim 2, wherein R 1 is selected from one of 4-phenyl, 4-tert-butylphenyl, 4-fluorophenyl, 4-methoxyphenyl, 4-methylphenyl; And/or R 2 is C1-C12 straight or branched alkyl; And/or, X is chloro.
  4. 4. The method according to claim 2, wherein in the step (1), the reaction temperature is 80 to 120 ℃ and the reaction time is 2 to 10 hours; And/or in the step (1), the catalyst is at least one of palladium acetate, diphenylphosphine ferrocene palladium dichloride, tetraphenylphosphine palladium, dichloro diphenylphosphine palladium, bis (tri-tertiary butyl phosphine) palladium, nickel acetate, diphenylphosphine ferrocene nickel dichloride, tetraphenyl phosphine nickel, dichloro diphenylphosphine nickel and bis (tri-tertiary butyl phosphine) nickel, and the molar ratio of the catalyst to the compound shown in the general formula (II) is 0.0001:1-0.01:1; And/or, in the step (1), the alkaline reagent is at least one of Cs 2 CO 3 、K 2 CO 3 、Na 2 CO 3 、Li 2 CO 3 .
  5. 5. The preparation method according to claim 2, wherein in the step (2), the temperature of the reduction reaction is-30-20 ℃ for 2-5 hours, the temperature of the dehydration reaction is 60-130 ℃ for 1-4 hours; And/or in the step (2), the solvent adopted in the reduction reaction is at least one of methanol, ethanol, benzyl alcohol and ethylene glycol, the reducing agent is at least one of sodium borohydride, lithium aluminum hydride, potassium borohydride and sodium cyanoborohydride, the reaction solvent adopted in the dehydration reaction is at least one aromatic solvent of toluene, xylene, trimethylbenzene, tetramethylbenzene and chlorobenzene, the organic acid is at least one of p-toluenesulfonic acid, formic acid and acetic acid, and the molar ratio of the alcohol compound to the organic acid is 5:1-40:1.
  6. 6. The preparation method of claim 2, wherein in the step (3), the anhydrous solvent is a mixed solution of furan solvent and aromatic solvent or a mixed solution of ether solvent and aromatic solvent, the furan solvent is tetrahydrofuran, the ether solvent is ethylene glycol dimethyl ether, the aromatic solvent is at least one of toluene, xylene, ethylbenzene and propylbenzene, and the volume ratio of the furan solvent to the aromatic solvent is 1:4-20; and/or in the step (3), the reducing agent is at least one of n-butyllithium, tert-butyllithium and methyllithium, and the molar ratio of the dimethyldichlorosilane to the compound (V) is 2-1; And/or in the step (3), the temperature of the reduction reaction is-30-25 ℃ and the time is 2-5h, and the temperature of the reaction of the compound shown in the general formula (VI) and the dimethylchlorosilane is-30-25 ℃ and the time is 8-12h.
  7. 7. The method according to claim 2, wherein in the step (4), the anhydrous polar solvent is at least one of diethyl ether, tetrahydrofuran, methyl tert-butyl ether; And/or in the step (4), the reducing agent is at least one of n-butyllithium, tert-butyllithium and methyllithium; And/or in the step (4), the temperature of the reduction reaction is-35-25 ℃, the reaction time is 2-5h, the temperature of the reaction of the lithium salt compound shown in the general formula (VIII) and the metal chloride is-30-25 ℃, and the reaction time is 10-15h; and/or in the step (4), the molar ratio of the compound shown in the general formula (VIII) to the metal halide is 2:1.8-2:2.2.
  8. 8. Use of a chiral bridged metallocene compound according to claim 1 or obtained by the preparation method according to any one of claims 2 to 7 as a propylene polymerization catalyst.
  9. 9. A propylene polymerization catalyst comprising the chiral bridged metallocene compound of claim 1 or the chiral bridged metallocene compound obtained by the preparation method of any one of claims 2 to 7.
  10. 10. A polypropylene catalyzed polymerization reaction characterized in that the reaction uses the chiral bridged metallocene compound of claim 1 or the chiral bridged metallocene compound obtained by the preparation method of any one of claims 2 to 7 as a propylene polymerization catalyst.

Description

Chiral bridged metallocene compound and preparation method and application thereof Technical Field The invention belongs to the technical field of alkene polymerization, and relates to a chiral bridged metallocene compound, a preparation method and application thereof. Background The polypropylene material is widely applied to the fields of clothing, daily necessities, medical and health, food industry and the like, and is a material with excellent performance. With the improvement of processing technology, the requirements for catalysts required for producing polypropylene are becoming higher and higher. At the beginning of the eighties of the last century, sinn (angel. Chem. Int. Ed. Engl.,1980,92,396) and Kaminsky (macromol. Chem., rapid Commun.,1983,4,417) et al have found a homogeneously catalyzed olefin polymerization system of metallocene complexes and MAO that can efficiently catalyze olefin polymerization. The discovery of methylaluminoxane has prompted rapid advances in this area. Metallocene and other transition metal complexes activated by methylaluminoxane are more than 10 times more active than Ziegler-Natta catalysts and are characterized by adjustable polymer molecular weight distribution and polymer tacticity (chem. Rev.,2000, 100:1253). The chiral-metallocene catalyst regulates the structure of polypropylene mainly by regulating the chiral structure of the catalyst. Metallocene compounds with C2 symmetry, whose racemic metal cations are achiral, but, due to steric hindrance, only monomers which are chirally matched to the growing chain are more involved in the coordination, thus isotactic polypropylene can be obtained (J. Organomet. Chem.,1982,232 (3): 233-47). Bridged metallocene catalysts have more excellent catalytic properties (Macromolecules, 2002, 35:5382-5387), and are particularly widely used in the synthesis of zirconocenes. Among them, the zirconocene complex (SBI type) having SiMe 2 bridge and (2-methyl-4-phenyl) substituent shows good activity, can catalyze and prepare high isotactic polypropylene, and has great potential in development of isotactic polypropylene (ANGEWANDTE CHEMIE International Edition IN ENGLISH,1980,19 (11): 857-875.). The Influence of Aromatic Substituents on the Polymerization Behavior of Bridged Zirconocene Catalysts：Spaleck(Organometallics,1994,13(3):954-963.) 7 Novel bridged zirconocenes were introduced for synthesis and isotactic polypropylene was prepared in propylene polymerization with methylaluminoxane as cocatalyst. Their polymerization behaviour in propylene and ethylene polymerizations was examined and discussed. The aromatic substituents in the appropriate positions of the zirconocene ligand framework lead to catalyst activity and the polypropylene molecular weight is much higher than any of the previously described metallocene systems. The effectiveness of these substitutions is strongly dependent on their position and non-incremental synergy with the alkyl substituents on the ligand framework as demonstrated by structural changes. The electronic effect can well explain the high activity of the system, while the steric effect clearly plays a more important role for the high stereospecificity and high molecular weight of the polymer. However, the technology has obvious disadvantages that (1) the reagent used in the process of preparing the catalyst is Na which is a dangerous metal reagent, and (2) the raw materials used for producing the catalyst are expensive. Metallocenes with arylsubstituted indenyl-derivatives as ligands,process for their preparation and their use as catalysts.J.Organomet.Chem.2002,664,5-26. Various metallocenes having aryl-substituted indenyl derivatives as ligands, processes for their preparation and their use as catalysts are disclosed, including metallocene catalyst ligands having a plurality of benzene ring structures. However, this technique has obvious disadvantages of (1) purification by column method in the post-treatment step of the silicon bridging reaction, but the method is not suitable for subsequent pilot scale production, and (2) it is a plurality of metallocenes with aryl substituted indenyl derivatives as ligands, the catalytic activity of the catalyst is relatively low, the melt index of the synthesized polypropylene is low, and the isotacticity is low. Disclosure of Invention The technical problem to be solved by the invention is that the route is complex when the precursor is synthesized in the process of synthesizing the metallocene catalyst in the prior art, and the chromatographic column separation cost is high in the post-treatment process, so that the method is not suitable for mass production. The invention aims to provide a novel chiral bridged metallocene compound, a preparation method and application thereof, and the preparation method of the invention provides a synthetic route of the metallocene compound produced in an amplifying way, so that the reaction steps are simplified, the post-treatm