Application of 4-mephnhli in catalyzing hydroboration reaction of imine and borane

Patent metadata

Field	Value
Publication number	US-2021221829-A1
Application number	US-202117225568-A
Country	US
Kind code	A1
Filing date	Apr 8, 2021
Priority date	Oct 8, 2018
Publication date	Jul 22, 2021
Grant date	—

Abstract

The present invention relates to an application of 4-MePhNHLi, in particular, to an application of 4-MePhNHLi in catalyzing hydroboration reaction of imine and borane. A catalyst, borane, and imine are stirred and mixed uniformly in sequence for reaction for 1-2 hours, the reaction is terminated by exposure to air, and the solvent in the reaction liquid is removed under reduced pressure to obtain borate esters having different substituents. According to the present invention, 4-MePhNHLi can catalyze hydroboration reaction of imine and borane at high activity at room temperature, the amount of catalyst is only 4-5 mol % of the molar mass of imine, and the reaction can reach a yield of more than 90%; compared with an existing catalytic system, simple 4-MePhNHLi is used, the reaction conditions are mild, and the yield of borate esters having different substituents can reach 99% in optimized conditions.

First claim

1 . A method of preparing a borate ester comprising:
reacting an imine with a borane in an organic solvent and in the presence of 4-MePhNHLi as a catalyst at room temperature under anhydrous, oxygen-free, and inert gas conditions for 1-2 hours; and stirring in air to stop reaction and to obtain the borate ester.

2 . The method of claim 1 , wherein:
the imine has the following structure:

the borane is pinacol borane;
the borate ester has the following structure:

and
R 1 and R 2 are independently selected from the group consisting of halogen, methyl and methoxy.

3 . The method of claim 1 , wherein the organic solvent is tetrahydrofuran.

4 . The method of claim 1 , wherein an amount of 4-MePhNHLi is 4% to 5% of a molar amount of the imine.

5 . The method of claim 1 , wherein a molar ratio of the imine to the borane is 1:1 to 1:1.2.

6 . The method of claim 5 , wherein the molar ratio of the imine to the borane is 1:1.2.

Assignees

• Univ Soochow

Inventors

• Xue Mingqiang
• Xu Xiaojuan
• Yan Dandan

Classifications

• C07F5/022 Primary

  without C-boron linkages · CPC title

• B01J31/02

  containing organic compounds or metal hydrides · CPC title

• C07F5/04 Primary

  Esters of boric acids · CPC title