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CN-121974779-A - Hydroboration reaction method of rare earth metal complex catalytic ketone

CN121974779ACN 121974779 ACN121974779 ACN 121974779ACN-121974779-A

Abstract

The invention relates to the field of organic compound synthesis, in particular to a hydroboration reaction method of rare earth metal complex catalytic ketone. The hydroboration reaction method of the rare earth metal complex catalytic ketone comprises the steps of mixing the rare earth metal complex, pinacol borane, ketone and a solvent in an inert atmosphere for reaction, wherein the chemical formula of the rare earth metal complex is RE (OTf) 3 , and RE is a rare earth element. The invention relates to a hydroboration reaction method of catalyzing ketone by using trifluoromethane sulfonic acid rare earth metal (RE (OTf) 3 ), which is a commercial product with low price, simple operation, high reaction activity, wide substrate range and high yield.

Inventors

  • HUANG ZEMING
  • FENG YUXIN
  • WANG RURU

Assignees

  • 安徽工程大学

Dates

Publication Date
20260505
Application Date
20260313

Claims (8)

  1. 1. A method for catalyzing hydroboration of ketone by rare earth metal complex, which is characterized by comprising the following steps: Mixing the rare earth metal complex, pinacol borane, ketone and a solvent in an inert atmosphere for reaction; The chemical formula of the rare earth metal complex is RE (OTf) 3 , wherein RE comprises rare earth elements.
  2. 2. The method of claim 1, wherein RE (OTf) 3 is selected from La, lu, Y or Sc.
  3. 3. The method for catalyzing the hydroboration reaction of ketone by using the rare earth metal complex according to claim 1, wherein the dosage ratio of the rare earth metal complex, ketone, pinacolborane and solvent is (0.001-0.02) mmol to (1.05-1.2) mmol to (0.1-0.5) mL.
  4. 4. The method for hydroboration of a rare earth metal complex catalyzed ketone according to claim 1, wherein the temperature of the reaction is 10-30 ℃ and the time of the reaction is 5-720 min.
  5. 5. The method for hydroboration of a rare earth metal complex catalyzed ketone according to claim 1, wherein the ketone comprises an aryl ketone.
  6. 6. The method for the hydroboration of rare earth metal complex catalyzed ketones according to claim 5, wherein the aryl ketones comprise at least one of acetophenone, 2-methylacetophenone, 3-methylacetophenone, 4-methylacetophenone, 2, 6-dimethylacetophenone, 4-tert-butylacetophenone, 2-chloroacetophenone, 3-chloroacetophenone, 4-chloroacetophenone, 2-methoxyacetophenone, 4-methoxyacetophenone, 1-naphthanone and 2-naphthanone.
  7. 7. The method for the hydroboration reaction of a rare earth metal complex catalyzed ketone according to claim 1, wherein the solvent comprises tetrahydrofuran and/or toluene.
  8. 8. The method for hydroboration of rare earth metal complex catalyzed ketone according to claim 1, wherein after the reaction is completed, ethyl acetate is added to terminate the reaction, then the solvent is distilled off under reduced pressure, and the solvent is purified by hydrolysis of silica gel column.

Description

Hydroboration reaction method of rare earth metal complex catalytic ketone Technical Field The invention relates to the field of organic compound synthesis, in particular to a hydroboration reaction method of rare earth metal complex catalytic ketone. Background Alcohol compounds have a variety of uses, and can be used as solvents, fuels, or intermediates for pharmaceutical molecules. There are various methods for synthesizing alcohols, such as reduction of ketone, addition of olefin, and synthetic routes of ketone and formazan. However, it is known that the hydroboration reaction of the rare earth metal on the ketone is not much studied, and the catalyst is generally high in load, relatively complex in catalyst synthesis route, and not mild in reaction condition. In recent years, researchers Victoria l.weidner, such as literature "ACS catalyst 2017, 7, 1244-1247," use La N (SiMe 3)2]3 to catalyze the hydroboration of ketones, which ends rapidly at 25 ℃ (conversion can exceed 99% in 5 min), while at the same time the catalyst loading is very low, but the catalyst price is somewhat high. Researchers Shen Qi, such as the literature "org. Lett., 2017, 19, 3382-3385", used Cp 3 Ln (ln=y, yb, sm, nd, la, cp=cyclopentadienyl) to catalyze the hydroboration of ketones in yields as high as 99%. The catalyst has simple preparation method, but has harsh preparation conditions and high price even if purchased. As in the literature "Dalton Trans.2017, 46, 7750-7757" researchers Rebeca Ar e valo use [ Re (bipy) (CO) 3 (L) ] X (L=labile ligand, X= [ BAr F4]- or [ B (3, 5-di-tBu-cat) 2]-) to catalyze the hydroboration of ketones, most of the products can reach 100%, but their catalyst loading is slightly higher (5 mol%), the reaction temperature is slightly higher (80 ℃) and the reaction conditions are not gentle. For example, a researcher Yao Yingming in the literature "J.org. chem.2018, 83, 6093-6100" uses [ L 4Yb(L4H)] (H2L4 = (S) -2-tert-butyl-6- ((2- (hydroxydiphenylmethyl) pyrrolidin-1-yl) methyl) phenol) as a catalyst to conduct hydroboration research on ketone, the yield can reach 90-99%, but the catalyst load is high (10 mol%), and the reaction time is long (8 h). As in literature "Organometallics 2021, 40, 2529-2537" researchers Zhao Bei used La [ N (SiMe 3)2]3) and added phenyl functionalized TsDPEN as ligand for asymmetric hydroboration studies on ketones, yields could reach 95-99%, but with higher catalyst loadings (10 mol%) and longer reaction times (10 h). Therefore, developing a synthesis method with mild reaction conditions, high catalytic efficiency and simple operation is a key technical problem in the current technical field. Disclosure of Invention The invention provides a hydroboration reaction method of rare earth metal complex catalytic ketone, which uses trifluoromethanesulfonic acid rare earth metal (RE (OTf) 3) to catalyze the hydroboration reaction method of ketone, and the catalyst is a commercial product, and has the advantages of low price, simple and convenient operation, high reaction activity, wide substrate range and high yield. In order to solve the technical problems, the invention provides the following technical scheme: The invention provides a hydroboration reaction method of rare earth metal complex catalytic ketone, which comprises the following steps: Mixing the rare earth metal complex, pinacol borane, ketone and a solvent in an inert atmosphere for reaction; The chemical formula of the rare earth metal complex is RE (OTf) 3, wherein RE comprises rare earth elements. Preferably, RE in RE (OTf) 3 is selected from La, lu, Y or Sc. That is, RE (OTf) 3 includes La (OTf) 3、Lu(OTf)3、Y(OTf)3 or Sc (OTf) 3. Preferably, the dosage ratio of the rare earth metal complex, ketone, pinacol borane and solvent is (0.001-0.02) mmol to 1mmol (1.05-1.2) mmol (0.1-0.5) mL. Preferably, the temperature of the reaction is 10-30 ℃, and the time of the reaction is 5-720 min. Preferably, the ketone comprises an aryl ketone. Preferably, the aryl ketone comprises at least one of acetophenone, 2-methylacetophenone, 3-methylacetophenone, 4-methylacetophenone, 2, 6-dimethylacetophenone, 4-tert-butylacetophenone, 2-chloroacetophenone, 3-chloroacetophenone, 4-chloroacetophenone, 2-methoxyacetophenone, 4-methoxyacetophenone, 1-naphtalenone and 2-naphtalenone. Preferably, the solvent comprises tetrahydrofuran and/or toluene. Preferably, the inert atmosphere comprises argon, nitrogen. Preferably, after the reaction is finished, ethyl acetate is added to terminate the reaction, then the solvent is distilled off under reduced pressure, and the reaction product is subjected to hydrolysis and purification by a silica gel column. In the invention, the hydroboration reaction method of the ketone is catalyzed by the rare earth metal complex, which comprises the following steps: and (3) weighing the rare earth metal complex in a glove box in an inert atmosphere, placing the rare earth metal complex in a reaction bottle, th