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CN-122011403-A - Preparation method of super-crosslinked polymer supported chiral ferrocene catalyst

CN122011403ACN 122011403 ACN122011403 ACN 122011403ACN-122011403-A

Abstract

The invention discloses a preparation method of a super-crosslinked polymer supported chiral ferrocene catalyst, and belongs to the technical field of organic chemistry. The preparation method comprises the steps of dissolving a ligand or a mixture containing the ligand and metal salt in a solvent in an inert gas atmosphere, stirring at room temperature until the ligand or the mixture is dissolved, adding an aryl-containing comonomer, continuously stirring and dissolving to obtain a reaction solution, adding Lewis acid or Bronsted acid, and carrying out a Friedel-crafts alkylation reaction to obtain the supported chiral ferrocene catalyst. Wherein the ligand is selected from compounds shown as L1-L12. Compared with the previous covalent bond polymerization method, the loading scheme does not need to modify the catalyst, has larger application potential for a series of small molecule catalysts containing aromatic rings, and has the advantages of simplicity, high efficiency and better universality.

Inventors

  • YOU HENGZHI
  • WANG CHAO
  • WU LIPING
  • HUANG JUNRONG
  • ZHU YUXIANG
  • CHEN FENER

Assignees

  • 深圳连续制药科技有限公司

Dates

Publication Date
20260512
Application Date
20251210
Priority Date
20250815

Claims (10)

  1. 1. The preparation method of the supported chiral ferrocene catalyst is characterized by comprising the following steps of: (1) Under the inert gas atmosphere, dissolving a ligand or a mixture containing the ligand and metal salt in a solvent, and stirring at room temperature until the ligand and the metal salt are dissolved to obtain a reaction solution; (2) Adding Lewis acid or Bronsted acid into the reaction liquid to carry out the Friedel-crafts alkylation reaction to obtain the supported chiral ferrocene catalyst.
  2. 2. The method of manufacturing according to claim 1, comprising the steps of: (1) Under the inert gas atmosphere, dissolving a ligand or a mixture containing the ligand and metal salt in a solvent, stirring at room temperature until the ligand or the mixture is dissolved, adding an aryl-containing comonomer, and continuously stirring and dissolving to obtain a reaction solution; (2) Adding Lewis acid or Bronsted acid into the reaction liquid to carry out the Friedel-crafts alkylation reaction to obtain the supported chiral ferrocene catalyst.
  3. 3. The method of preparation according to claim 1 or 2, wherein the ligand is selected from the group consisting of compounds represented by L1-L12: ; and/or the metal salt comprises [Rh(COD)Cl] 2 、[Ir(COD)Cl] 2 、[Rh(COD) 2 ]BF 4 、[Rh(COD) 2 ]SbF 6 、[Rh(COD) 2 ]BARF; And/or the metal salt is used in an amount of 0.5 to 1 equivalent with respect to the ligand.
  4. 4. The method of claim 1 or 2, wherein the aryl-containing comonomer comprises a compound represented by C1-C7: and/or the addition amount of the aryl group-containing comonomer relative to the ligand is 1 to 10 equivalents.
  5. 5. The preparation method according to claim 1 or 2, wherein the solvent comprises a compound represented by S1 to S6: ; And/or adding solvent to make the concentration of ligand reach 0.01-1mmol/ml, and/or adding solvent, stirring at room temperature until completely dissolved, and stirring for 10-60 min.
  6. 6. The preparation method according to claim 1 or 2, wherein the lewis acid comprises at least one of ferric trichloride, aluminum trichloride and tin tetrachloride, and/or the bronsted acid comprises at least one of concentrated sulfuric acid and trifluoromethanesulfonic acid, and/or the lewis acid or bronsted acid is used in an amount of 5 to 75 equivalents relative to the ligand, and/or the addition of the lewis acid or bronsted acid is performed under an inert gas flow.
  7. 7. The preparation method according to claim 1 or 2, wherein the reaction time of the Packed alkylation reaction is 1-48 h, the reaction is quenched by a quencher comprising at least one of absolute ethanol, absolute methanol and aqueous hydrochloric acid, and/or the reaction temperature of the Packed alkylation reaction is-20-80 ℃.
  8. 8. A supported chiral ferrocene catalyst, characterized in that it is prepared by the method of any one of claims 1-7.
  9. 9. A supported chiral ferrocene catalyst, characterized in that the supported chiral ferrocene catalyst has the following general formula: ; R is H, CH 3 、CF 3 in para or meta position, R' is H, CH 3 , Z is S, O, x=1, y=0-10.
  10. 10. Use of a supported chiral ferrocene catalyst according to any of claims 8-9 in an asymmetric hydrogenation reaction.

Description

Preparation method of super-crosslinked polymer supported chiral ferrocene catalyst Technical Field The invention belongs to the technical field of organic chemistry, and particularly relates to a preparation method of a super-crosslinked polymer supported chiral ferrocene catalyst. Background Ferrocene is an advantageous framework and plays an important role in chiral ligand and catalyst design. By virtue of its economical, thermal stability and remarkable tolerance to moisture, oxygen and various active agents, the structure plays a key role in the field of asymmetric catalysis in academia and industry. The various classes of chiral ferrocene ligands developed to date, catalysts formed upon complexation with metals, have exhibited extremely high activity in a variety of asymmetric reactions. However, the chiral ferrocene ligands still have obvious defects that the cost is high due to a complex synthetic route and severe preparation conditions, and the catalyst is difficult to separate and recover from a reaction system due to excellent organic solvent solubility, so that the difficulty of separating and purifying the product is increased, the recycling of an expensive catalyst is blocked, and the wider industrial application of the catalyst is further limited. In order to solve the problems, the chiral ferrocene ligand is immobilized to prepare a heterogeneous catalyst, so that the catalyst is expected to be promoted to be reused, the product purification process is simplified, and the limitations are solved to a certain extent. To date, a large number of chiral heterogeneous chiral ferrocene catalysts have been reported and successfully used for asymmetric reactions, and despite encouraging results, many immobilization methods are inherently cumbersome in steps, complicated synthetic routes make the preparation process time consuming and costly, which is contrary to the original objective of cost reduction by immobilization techniques. The solvent weaving method is a preparation method of the super-crosslinked microporous polymer based on an aromatic ring structure. The innovative method is characterized in that the solvent is used as a cross-linking agent, so that no additional cross-linking agent is needed. This approach significantly simplifies the polymerization scheme compared to previously reported synthetic schemes. However, previous studies focused mainly on immobilized small molecule chiral phosphates or achiral ligands, and no report has been made to date on the application of this HCPs method to chiral ligand/metal complexes. The application of the chiral ligand/metal complex to immobilization of chiral ligand/metal complex still faces a plurality of challenges: (1) The difficult problem of chiral environment maintenance is that the severe reaction conditions in the crosslinking process can lead to racemization or destruction of the three-dimensional configuration of chiral ligand, and the original chiral microenvironment is difficult to maintain. (2) Stability of metal active center problems under the high activity conditions of the crosslinking reaction, the metal complex may undergo dissociation or oxidation-reduction reaction, resulting in deactivation of the active center or structural change. (3) Ligand load uniformity control is difficult because chiral ligands typically have complex spatial structures, their uniform distribution and directional immobilization in crosslinked networks face significant challenges, which can easily lead to maldistribution of active sites. (4) The problem of the matching of the pore structure and the catalytic activity is that chiral catalytic reaction often needs a specific space environment, and the random pore structure formed by crosslinking can not provide ideal chiral cavities, so that the stereoselectivity is affected. (5) The structural integrity is maintained during the post-treatment process, where the crosslinked product typically requires a strong acid treatment to remove the catalyst, which may further disrupt the chiral ligand-metal coordination structure. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a preparation method of a super-crosslinked polymer supported chiral ferrocene catalyst. In a first aspect, the application provides a method for preparing a supported chiral ferrocene catalyst, comprising the following steps: (1) Under the inert gas atmosphere, dissolving a ligand or a mixture containing the ligand and metal salt in a solvent, and stirring at room temperature until the ligand and the metal salt are dissolved to obtain a reaction solution; (2) Adding Lewis acid or Bronsted acid into the reaction liquid to carry out the Friedel-crafts alkylation reaction to obtain the supported chiral ferrocene catalyst. In some embodiments, the method of making comprises the steps of: (1) Under the inert gas atmosphere, dissolving a ligand or a mixture containing the ligand and metal salt in a solvent, sti