CN111978537B

CN111978537B - Chiral catalyst (S) -DTP-COF, and preparation, recycling method and application thereof

Info

Publication number: CN111978537B
Application number: CN202010652202.XA
Authority: CN
Inventors: 董育斌; 阚璇; 王建成; 尚金燕; 乔华
Original assignee: Shandong Normal University
Current assignee: Shandong Normal University
Priority date: 2020-07-08
Filing date: 2020-07-08
Publication date: 2022-05-13
Anticipated expiration: 2040-07-08
Also published as: CN111978537A

Abstract

The invention belongs to the technical field of catalyst preparation, and particularly relates to a chiral catalyst and (S) -DTP-COF as well as a preparation method and application thereof. The preparation method of the chiral catalyst (S) -DTP-COF comprises the following steps: cuprous trifluoromethanesulfonate and (S, S) -2, 6-bis (4-phenyl-2-oxazoline-2-yl) pyridine are placed in a round-bottom flask, chloroform is used as a solvent, and the mixture is stirred to be dissolved. 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde, 1,3, 5-tris (4-aminophenyl) benzene and phenylacetylene are added into a round-bottom flask and stirred for 48 hours at room temperature. Finally adding acetic acid, and stirring for 24-48h to obtain (S) -DTP-COF. The catalyst can effectively catalyze the Michael addition reaction, does not need high temperature, has small using amount and no other additives, and can realize heterogeneous catalysis. Meanwhile, the catalyst can be recycled and is easy to recover, the utilization rate of the catalyst is improved, the cost is reduced, and the method is favorable for industrial popularization and application.

Description

Chiral catalyst (S) -DTP-COF, and preparation, recycling method and application thereof

Technical Field

The invention belongs to the technical field of catalyst preparation, and particularly relates to a chiral catalyst and (S) -DTP-COF as well as a preparation method and application thereof.

Background

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The current research on chiral science and technology covers the fields of preparation of chiral compounds such as drugs and fine chemicals, as well as sensing, magnets, molecular switches, optical devices, and the like. In recent years, chiral materials have attracted much interest because of their applications in the chiral field and their ability to be recycled. Meanwhile, the demand for chiral materials is increasing. Chiral organic porous materials are an important class of chiral materials. It is completely connected by means of covalent bond, and its material contains no metal, and its cost is low and toxicity is low. The pure organic framework of the material enables the material to have good hydrophobic property, is beneficial to the enrichment of object molecules or reaction substrates, and greatly improves the chiral application performance of the material. The chiral precursors are rich and various, and the chiral organic porous material has a larger application prospect.

COFs (Covalent Organic Framework, COF) are a hot point of research in recent years, and compared with the traditional porous materials, COFs have the characteristics of large specific surface area, ordered pore channels, adjustable size, rich types and the like, have wide potential application in the fields of adsorption separation, energy, catalysis, photoelectricity, biological imaging, medicine and the like, and become a hot point of research in the fields of chemistry and materials in recent years. The COFs are rich in construction units, and the composition and the structure of the COFs can be changed simultaneously by using a chemical method, so that the functions and the internal environment are regulated and controlled, and the COFs are an ideal platform for constructing functional chiral porous materials. However, the inventors found that: so far, the reports of chiral COF are very few, and therefore, the development of a strategy for constructing chiral COF is an important challenge to be solved in the field.

Disclosure of Invention

In order to solve the problems, the invention provides a chiral catalyst (S) -DTP-COF, a preparation method thereof and application thereof in catalyzing Michael addition reaction. The chiral catalyst provided by the invention has high utilization rate and mild reaction conditions, and can effectively reduce the catalysis cost.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

in a first aspect of the present invention, there is provided a chiral catalyst (S) -DTP-COF, having the following structural formula:

in a second aspect of the present invention, there is provided a method for preparing a chiral catalyst (S) -DTP-COF, comprising:

cuprous trifluoromethanesulfonate and (S, S) -2, 6-bis (4-phenyl-2-oxazoline-2-yl) pyridine are uniformly mixed in a solvent; then adding 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde, 1,3, 5-tri (4-aminophenyl) benzene and phenylacetylene, and stirring at room temperature for 48-50 h; then adding acetic acid, and stirring for 24-48h to obtain (S) -DTP-COF.

In a third aspect of the invention, the application of the chiral catalyst (S) -DTP-COF in catalyzing Michael addition reaction is provided.

In a fourth aspect of the invention, a method for recovering a chiral catalyst (S) -DTP-COF is provided, wherein after the Michael addition reaction is finished, centrifugal separation is carried out to obtain the catalyst (S) -DTP-COF.

The invention has the beneficial effects that:

(1) the invention has low reaction temperature, good reaction effect and reduced energy consumption.

(2) The catalyst is catalyzed by the Michael addition reaction, so that heterogeneous catalysis is realized, the using amount of the catalyst is small, the catalyst is easy to recover, the utilization rate of the catalyst is improved, and the cost is reduced.

(3) The method is simple, low in cost, strong in practicability and easy to popularize.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is an infrared spectrum of (S) -DTP-COF of the present invention together with a ligand;

FIG. 2 is a PXRD spectrum of (S) -DTP-COF of the present invention;

FIG. 3 is a circular dichroism spectrum of (S) -DTP-COF of the present invention.

FIG. 4 is a graph showing the catalytic effect of (S) -DTP-COF of the present invention.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

A preparation method of a chiral catalyst S-T-CCOF comprises the following steps:

cuprous trifluoromethanesulfonate and (S, S) -2, 6-bis (4-phenyl-2-oxazoline-2-yl) pyridine are placed in a round-bottom flask, chloroform is used as a solvent, and the mixture is stirred and dissolved. 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde, 1,3, 5-tris (4-aminophenyl) benzene and phenylacetylene are added into a round-bottom flask and stirred for 48 hours at room temperature. Finally adding acetic acid, and stirring for 24-48h to obtain (S) -DTP-COF.

In some embodiments, the cuprous trifluoromethanesulfonate, (S, S) -2, 6-bis (4-phenyl-2-oxazolin-2-yl) pyridine, 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde, 1,3, 5-tris (4-aminophenyl) benzene, phenylacetylene are in a molar ratio of 1:1:9:6:3.7 to improve reaction efficiency and yield.

Preferably, the chloroform solvent is in an amount of 25mL to effectively dissolve cuprous trifluoromethanesulfonate and (S, S) -2, 6-bis (4-phenyl-2-oxazolin-2-yl) pyridine.

Preferably, the room temperature is 15-25 ℃, and the reaction can be carried out in different seasons and regions.

The chiral catalyst (S) -DTP-COF is applied to catalyzing Michael addition reaction.

The application method specifically comprises the following steps:

cyclohexanone, pTsOH, EtOH, (S) -DTP-COF was stirred at 25 ℃ for 10 minutes. Adding nitroolefin, and stirring the mixture at 25 ℃ to react to obtain a corresponding product.

Wherein the molar ratio of the cyclohexanone to the pTsOH to the catalyst (S) -DTP-COF to the nitroolefin is 10:2:3.3: 0.5. The catalyst is catalyzed by the Michael addition reaction, so that heterogeneous catalysis is realized, the using amount of the catalyst is small, the catalyst is easy to recover, the utilization rate of the catalyst is improved, and the cost is reduced.

The reaction is as follows:

finally, the invention also provides a recovery method of the chiral catalyst (S) -DTP-COF, and particularly, after the Michael addition reaction is finished, the catalyst (S) -DTP-COF is obtained by rapid centrifugation.

The present invention is described in further detail below with reference to specific examples, which are intended to be illustrative of the invention and not limiting.

Example 1: synthesis of (S) -DTP-COF

12mg (0.02mmoL) of cuprous trifluoromethanesulfonate and 8mg (0.02mmoL) of (S, S) -2, 6-bis (4-phenyl-2-oxazolin-2-yl) pyridine were placed in a 50ml round-bottomed flask, and 25ml of chloroform was added thereto and dissolved by stirring. 38.40mg (0.198mmoL) of 2, 5-dimethoxybenzene-1, 4-dicarbaldehyde, 43mg (0.122mmoL) of 1,3, 5-tris (4-aminophenyl) benzene, and 90. mu.l (0.819mmoL) of phenylacetylene were put in a round-bottomed flask and stirred at room temperature for 48 hours. Finally, 15 mul of acetic acid is added and stirred for 24-48 h. After the reaction, the reaction mixture was centrifuged, washed 3 times with chloroform and 3 times with ethanol to obtain (S) -DTP-COF.

We characterized the polymer by IR, PXRD, CD spectra and the results are shown in figures 1, 2, 3, respectively.

Example 2:

1mL (10mmol) of cyclohexanone, 344.4mg (20% mol) of pTsOH, EtOH (2mL), 5mg (3.3 mol%) (S) -DTP-COF were stirred at 25 ℃ for 10 minutes. Nitrocellulose was then added (0.5mmol) and the mixture was stirred at 25 ℃ for 48 hours. After the reaction was completed, the reaction system was cooled to room temperature, and the catalyst was filtered off by centrifugation. After the solvent is removed by rotary evaporation, the product is purified by a silica gel column to obtain the corresponding product. The catalyst was recovered and put into the next reaction, and the yield was directly calculated by separation, and the catalytic effect is shown in fig. 4.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents can be made in the technical solutions described in the foregoing embodiments, or equivalents thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. Although the present invention has been described with reference to the specific embodiments, it should be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. A chiral catalyst (S) -DTP-COF is characterized in that the structural formula is as follows:

2. a preparation method of chiral catalyst (S) -DTP-COF is characterized by comprising the following steps:

3. The method for preparing the chiral catalyst (S) -DTP-COF according to claim 2, wherein the molar ratio of the cuprous trifluoromethanesulfonate, the (S, S) -2, 6-bis (4-phenyl-2-oxazoline-2-yl) pyridine, the 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde, the 1,3, 5-tris (4-aminophenyl) benzene and the phenylacetylene is 1-1.5: 9-12: 6-9: 3.7-6.

4. The process for the preparation of chiral catalyst (S) -DTP-COF according to claim 2, characterized in that the solvent is chloroform.

5. The process for the preparation of chiral catalyst (S) -DTP-COF according to claim 2, characterized in that the room temperature is 15-25 ℃.

6. The process for preparing chiral catalyst (S) -DTP-COF according to claim 2, wherein the reaction is terminated, centrifuged and washed to obtain (S) -DTP-COF.

7. The method for preparing the chiral catalyst (S) -DTP-COF according to claim 6, wherein the washing step comprises washing with chloroform for 3-4 times and then with ethanol for 3-4 times.

8. Use of the chiral catalyst (S) -DTP-COF of claim 1 for the catalysis of the michael addition reaction of a nitroalkene and cyclohexanone.

9. A method for recovering a chiral catalyst (S) -DTP-COF according to claim 1, wherein the catalyst (S) -DTP-COF is obtained by centrifugal separation after the Michael addition reaction of nitroolefin and cyclohexanone.