Bisoxazoline ligand compound and synthetic method thereof

A technology of ligand compound and bisoxazoline, which is applied in the field of bisoxazoline ligand compound and its synthesis, can solve the problems of harsh reaction temperature, harsh reaction temperature, lack of etc., and achieve high yield and good enantiometry Body-selective ee value, the effect of a wide range of applications

Pending Publication Date: 2020-01-24
WUYI UNIV
View PDF1 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But on the one hand, the amount of this type of catalyst is more (10% mol); on the other hand, the temperature of the reaction is relatively harsh (-78 ° C); and the activity and enantioselectivity of the catalyst are relatively low
[0005] Desimoni et al. recently discovered that (4'S,5'S)-2,6-bis[4'-(triisopropylsilyl)oxymethyl-5'-phenyl-1',3'-oxazoline-2'- ] The complex formed by pyridine and scandium trifluoromethanesulfonate ligand is used to catalyze the DA reaction of α, β-unsaturated N-acryloyl oxazolidinone, which can achieve 99% enantioselectivity, but there are also Disadvantages of large amount of catalyst (10% mol) and harsh reaction temperature (-50°C)
[0006] It can be seen from the above that although the ligand system is already sound, compared with PyboxLigand, BoxLigand lacks a corresponding ligand with a substituent on the carbon connected to the oxygen atom in the structure.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Bisoxazoline ligand compound and synthetic method thereof
  • Bisoxazoline ligand compound and synthetic method thereof
  • Bisoxazoline ligand compound and synthetic method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] A kind of bisoxazoline ligand compound

[0050] Its structural formula 7 or 8 is as follows:

[0051]

[0052] Among them, nBu is a n-butyl group, Me is a methyl group, N is a nitrogen atom, and O is an oxygen atom.

Embodiment 2

[0054] A kind of synthetic method of bisoxazoline ligand, comprises the following steps:

[0055] S1), the L-phenylalanine methyl ester hydrochloride 1 of 5g is dissolved in the DCM of 100mL, then add the Et of 8mL 3 N or iPr 2 Net, then add 6mL of Boc dropwise under ice bath 2 O, then transferred to room temperature and stirred for 5 h, monitored by TLC, the reaction of the raw materials was completed, and then adding about 100 mL of 5% citric acid aqueous solution to quench the reaction, extracted with DCM, and then the organic phase was 5% NaHCO 3 (aq.) washing, water washing, anhydrous Na 2 SO 4 Drying, filtering, spin-drying, and passing through the column yielded (tert-butoxycarbonyl)-L-phenylalanine methyl ester 2;

[0056]

[0057] S2), 2.6 g of (tert-butoxycarbonyl)-L-phenylalanine methyl ester 2 prepared in step S1) was dissolved in 10 mL of THF, and then 45 mL of methyl bromide was slowly added dropwise under ice bath or at room temperature Magnesium in tetr...

Embodiment 3

[0066] A kind of synthetic method of bisoxazoline ligand, specifically comprises the following steps:

[0067] S21), the L-phenylalanine methyl ester hydrochloride 1 of 10g was dissolved in the DCM of 200mL, then added the Et of 16.2mL 3 N or iPr 2 Net, then add 13.8mL of Boc dropwise under ice bath 2 O, after being transferred to room temperature and stirred for 5h, TLC monitoring, the raw material reaction was completed, and then adding about 200mL concentration of 5% citric acid aqueous solution to quench the reaction, DCM extraction, and the final organic phase was 5% NaHCO 3 (aq.) washing, water washing, anhydrous Na 2 SO 4 Drying, filtering, spin-drying, and passing through the column yielded (tert-butoxycarbonyl)-L-phenylalanine methyl ester 2;

[0068]

[0069] S22), dissolving 5g of (tert-butoxycarbonyl)-L-phenylalanine methyl ester 2 in 10ml-20ml of THF, then slowly add the freshly prepared n-butyl tetrahydrofuran solution of magnesium bromide, then transferr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a bisoxazoline ligand compound and a synthetic method thereof. The method comprises the following steps: synthesizing (tert-butoxycarbonyl)-L-phenylalanine methyl ester 2 by using L-phenylalanine methyl ester hydrochloride 1, synthesizing (S)-(3-hydroxy-3-methyl-1-phenylbut-2-yl)tert-butyl carbamate 3 or (S)-(3-butyl-3-hydroxy-1-phenylhept-2-yl)tert-butyl carbamate 5, synthesizing (S)-3-amino-2-methyl-4-phenylbutan-2-ol 4 or (S)-3-amino-2-methyl-4-phenylbutan-2-ol 6 by using the above materials, and finally, synthesizing the compound provided by the invention. The preparation method provided by the invention is simple, and has easy purification and a higher yield; and compared with a PyboxLigand, the substance prepared by the method realizes the purpose that carbon connected to an oxygen atom is connected with a substituent, and the substance synthesized by the method has a better ee value and better applications in asymmetric synthesis.

Description

technical field [0001] The invention relates to the technical field of organic compound synthesis, in particular to a bisoxazoline ligand compound and a synthesis method thereof. Background technique [0002] Chiral synthesis is the frontier research direction of organic chemistry and catalytic chemistry. With the increasing proportion of chiral drugs in the market, they have been successfully used in dihydrogenation reactions, Aldol reactions, hydrosilylation reactions, etc. Symmetrical synthesis. In view of the excellent performance of bisoxazolin ligands in some asymmetric synthetic reactions, our interest in ligands with dinitrogen was aroused. The Diels-Alder (DA) reaction is widely used in the synthesis of natural products and fine chemicals, and is an important method for the synthesis of six-membered cyclic compounds, which can form up to four chiral centers through a one-step reaction. Among many catalysts, the catalyst combined with chiral bisoxazoline ligand and...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/12
CPCC07D263/12
Inventor 马志强李颖徐学涛
Owner WUYI UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap