Method for preparing borate ester on basis of tricyclopentadienyl rare earth metal complex

Patent metadata

Field	Value
Publication number	US-11440924-B2
Application number	US-201716605249-A
Country	US
Kind code	B2
Filing date	Apr 15, 2017
Priority date	Apr 15, 2017
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

Disclosed is a method for preparing a borate ester on the basis of a tricyclopentadienyl rare earth metal complex, the method comprising the following steps: uniformly stirring and mixing a catalyst, a borane and a carbonyl compound for reaction to prepare a borate ester, wherein the catalyst is a tricyclopentadienyl rare earth metal complex; and the molecular formula of the tricyclopentadienyl rare earth metal complex can be expressed as: Ln(Cp)3, wherein Ln represents a rare metal selected from one of lanthanide elements. The preparation method has a higher catalytic activity, mild reaction conditions, a product that is easy to post-treat, a short reaction time, a low catalyst consumption amount, and a good range of applicable substrates, and can be used for industrial production.

First claim

The invention claimed is:

1. A method for preparing a borate ester in the presence of a tricyclopentadienyl rare earth metal complex, the method comprising the following steps:
uniformly stirring and mixing a catalyst, a borane and a carbonyl compound in a reaction to prepare the borate ester, wherein the catalyst is a tricyclopentadienyl rare earth metal complex; wherein the carbonyl compound is a ketone or an aldehyde; wherein the chemical formula of the tricyclopentadienyl rare earth metal complex is expressed as:

wherein Ln represents a rare earth metal.

2. The method according to claim 1 , wherein the borane is pinacolborane; wherein the ketone is an aromatic ketone or an aliphatic cyclic ketone; wherein the chemical formula of the aromatic ketone is represented by one of the following:

wherein R1 is phenyl, substituted-phenyl or heterocyclic aryl group;
wherein the chemical formula of the aliphatic cyclic ketone is represented by one of the following:

wherein n is 3-15;
wherein the chemical structural formula of aldehyde is represented by one of the following:

wherein R is hydrogen, halogen, methyl or methoxy group.

3. The method according to claim 1 , wherein an amount of the tricyclopentadienyl rare earth metal complex is 0.01-1% of a molar amount of carbonyl compound; wherein a molar ratio of the borane and the carbonyl compound is 1-1.2:1.

4. The method according to claim 1 , wherein the reaction is carried out in an organic solvent; wherein a reaction time is between 30 min and 1 h; wherein the reaction is carried out at room temperature.

5. The method according to claim 1 , further comprising: when the reaction is over, reducing pressure and removing solvent of reaction solution, adding n-hexane into a residual liquid, and obtaining various substituted borate esters.

6. A method comprising applying a tricyclopentadienyl rare earth metal complex as a catalyst for a reaction of a carbonyl compound with pinacolborane; wherein the chemical formula of the tricyclopentadienyl rare earth metal complex is:

wherein Ln represents a rare earth metal.

7. The method according to claim 6 , wherein Ln is a rare-earth metal selected from the group consisting of lanthanum, yttrium, neodymium, ytterbium and samarium; wherein the borane is pinacolborane; wherein the carbonyl compound is a ketone or an aldehyde; wherein the ketone is an aromatic ketone or an aliphatic cyclic ketone; wherein the chemical formula of the aromatic ketone is represented by:

wherein R1 is phenyl, substituted-phenyl or heterocyclic aryl group;
wherein the chemical formula of the aliphatic cyclic ketone is represented by one of the following:

wherein n is 3-15;
wherein the chemical formula of the aldehyde is represented by one of the following:

wherein R is hydrogen, halogen, methyl or methoxy group.

8. The method according to claim 6 , wherein of the tricyclopentadienyl rare earth metal complex is 0.01-1% of a molar amount of the carbonyl compound; wherein a molar ratio of the pinacolborane and the carbonyl compound is 1-1.2:1; wherein a reaction time is between 30 min and 1 h; wherein the reaction is carried out at room temperature.

9. A method for reaction of a borane with an aldehyde, the method comprising the following steps:
uniformly stirring and mixing the borane and the aldehyde in the presence of a catalyst, completely reacting the borane with the aldehyde at room temperature for 30 min to 1 h; wherein the catalyst is a tricyclopentadienyl rare earth metal complex having a chemical formula represented by:

wherein Ln represents a rare earth metal.

Assignees

• Univ Soochow

Inventors

• Xue Mingqiang
• Yan Dandan
• Chen Sufang
• Shen Qi

Classifications

• B01J2531/36

  Yttrium · CPC title

• B01J2231/344

  Boronation, e.g. by adding R-B(OR)2 · CPC title

• B01J2531/37

  Lanthanum · CPC title

• B01J31/2265

  Carbenes or carbynes, i.e.(image) · CPC title

• C07F5/04 Primary

  Esters of boric acids · CPC title