CN107803223A - Ferrocene cuprous cluster catalyst for catalyzing C-N coupling reaction and preparation method thereof - Google Patents

Abstract

The invention discloses a ferrocenyl cuprous cluster catalyst for catalyzing C-N coupling reaction and a preparation method thereof, the catalyst is a cuprous cluster complex based on a ferrocene selenium/tellurium ether ligand, coupling reaction of iodobenzene and imidazole under an alkaline condition is taken as template reaction, and the yield of a series of cuprous cluster compounds as the catalyst is represented by gas chromatography. The invention also discloses a preparation method of the catalyst. The yield of the series of catalysts at high temperature for six hours is 99%, and no solvent is added, so that the application of the series of catalysts in production is increased. Meanwhile, the method is environment-friendly, and reduces the pollution of the solvent to the environment. In addition, the series of cluster compounds have high stability and can be stored in the air for a long time.

Description

A kind of ferrocene cuprous cluster catalyst that catalyzes C-N coupling reaction and preparation method thereof

technical field

The invention relates to the technical field of metal organic catalytic materials, in particular to a ferrocene cuprous cluster catalyst for catalyzing C-N coupling reaction and a preparation method thereof.

Background technique

The copper-catalyzed Ullmann C-N coupling reaction is the most classic and important method for constructing aryl carbon-heterobonds. Compounds containing carbon-heterobonds (such as C-N, C-O, C-S bonds, etc.) are an important part of organic compounds. In life chemistry, C-N, C-O, and C-S bonds are mostly the key parts that determine their physiological activities. Therefore, small molecules The coupling of carbon-heterobonds in synthesis has always been a research hotspot in organic synthesis. How to obtain carbon-heterobonds in a simple, cheap, efficient and green way has always been the focus of scientists. At present, there are problems to be solved such as harsh reaction conditions, low catalytic conversion rate, solvent polarity, complicated post-treatment, and many extraction times, which greatly restrict its application. The catalysts in the present invention, ferrocene selenium and tellurite cuprous clusters, have breakthroughs such as high yield, no solvent, and short reaction time, which will greatly promote the application prospect of C-N coupling synthesis.

Contents of the invention

The object of the present invention is to provide a ferrocene cuprous cluster catalyst for catalyzing C-N coupling reaction, the catalyst can optimize reaction conditions and improve the application prospect of copper-catalyzed C-N coupling.

Another object of the present invention is to provide a preparation method of the above-mentioned catalyst.

In order to realize the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A ferrocene cuprous cluster catalyst that catalyzes C-N coupling reaction. The catalyst uses Se/Te as a binding site to form a coordination compound with cuprous, while the copper center and the ferrocene center act synergistically for catalysis. Described ferrocene selenium/telluride cuprous cluster catalyst comprises compound, and its structural formula general formula is as follows:

[ _{Cum X m L a} ] _b

in:

L = ; E=Se/Te; n=0 or 1 or 3; a; b; m≥1; X=I or Br;

R=-CH ₂ -or or

Above-mentioned, the synthetic formula of compound is as follows:

Wherein: E=Se/Te; n=0 or 1 or 3; a; b; m≥1; X=I or Br;

R=-CH ₂ -or or

The structural formula of the ligand of the above-mentioned ferrocene cuprous cluster is summarized as follows:

Wherein: E=Se/Te; n=0 or 1 or 3;

R=-CH ₂ -or or

This series of ferrocene cuprous clusters greatly reduces the activation energy of the reaction, thereby achieving the reaction conditions of reducing the reaction time and being solvent-free. A series of yields of this series of catalysts catalyzing the reaction of iodobenzene and imidazole under this condition were characterized by gas chromatography.

The selenium/tellurium and Se/Te mentioned in the present invention represent Se or Te.

The present invention also discloses a preparation method of the ferrocene selenium/telluride cuprous cluster catalyst having a catalytic effect on the C-N coupling reaction, comprising the following steps:

(1) Synthesis of ferrocenyl telluride ligand (taking L (R = methylene, n = 3, E = Te) as an example):

Under nitrogen atmosphere, add ferrocene, n-butyllithium and tellurium powder into 200-300ml tetrahydrofuran at a molar ratio of 1:6:1. After reacting at room temperature, spin the reaction solution to dryness and extract with dichloromethane. Purify by silica gel column chromatography and collect Fc ₂ Te ₂ .

Take a 100mL three-neck flask, under a nitrogen atmosphere, add Fc2Te2/Fc2Se2, sodium borohydride, and 1,3-dibromopropane in sequence at a molar ratio of 1:8:1. After the reaction is complete at room temperature, distill under reduced pressure and spin dry. Purification afforded L as a yellow solid.

When preparing the ferrocenyl selenide ligand with a structure similar to the above ligand, it is only necessary to replace the tellurium powder added in the above preparation process with selenium powder to prepare the ferrocenyl selenide ligand.

(2) Synthesis of cuprous clusters by interface method (taking compound L as an example, R=methylene, m=2, a=2, b=1, n=3, X=I, E=Te):

Weigh the ferrocenyl propane selenium/telluride ligand prepared in step (1) and dissolve it in a certain volume of dichloromethane, get the amount of the same substance CuI and dissolve it in acetonitrile; get the acetonitrile solution and add it dropwise to the upper layer of the dichloromethane solution , after standing for several days, cuprous cluster crystals appeared at the interface.

Catalyzed C-N coupling reaction experiment: Add 2.5mmol of iodobenzene, 0.375mmol of imidazole, 0.5mmol of lithium tert-butoxide, 10%mmol of cuprous cluster catalyst into a single-necked bottle, and seal the reaction for 6 hours at 110 degrees Celsius under nitrogen atmosphere; The stock solution was tested by gas chromatography to obtain the concentration of the product 1-phenylimidazole. Yield was obtained after calculation.

Table 1 Summary of properties of ferrocenyl telluride cuprous cluster C-N thermocatalysts

Table 2 Summary of C-N thermocatalyst properties of ferrocene selenide cuprous cluster catalyst

Beneficial effects: the invention discloses a ferrocene cuprous cluster catalyst that catalyzes the C-N coupling reaction. The catalyst catalyzes the reaction quickly and reacts under the condition of no solvent, which can reduce the cost of solvent and the cumbersome post-treatment; the selected The cluster compound is stable in the air, and the catalyst has wide sources, low price, non-toxicity and environmental friendliness, and has wide application in catalyzing C-N coupling reaction.

Description of drawings

Fig. 1 is the synthetic route map of ferrocene cuprous cluster catalyst of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments.

Experimental reagents:

Sodium borohydride (CP), cuprous iodide (CP), ferrocene (CP), selenium powder (CP) tellurium powder (CP) were purchased from Sinopharm Chemical Reagent Co., Ltd.; dichloromethane (AR), ethanol (AR) , acetonitrile (AR) were purchased from Wuxi Yasheng Chemical Co., Ltd.; anhydrous magnesium sulfate (AR) was purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd.; tetrahydrofuran (AR) and n-hexane (AR) were purchased from Shanghai Shihewei Chemical Co., Ltd.; silica gel (reagent grade) was purchased from Qingdao Ocean Chemical Factory Branch.

laboratory apparatus:

The rotary evaporator was purchased from Shanghai Shensheng Biotechnology Co., Ltd.; the digital display constant temperature water bath and magnetic heating stirrer were purchased from Guohua Electric Appliance Co., Ltd.; the vacuum pump was purchased from Shanghai Instrument Supply and Marketing Company; the S42-D(Ⅲ) circulating water vacuum pump was purchased from Gongyi Yingyu Yuhua Instrument Factory; electric vacuum drying oven was purchased from Shanghai Experimental Instrument Co., Ltd.; standard Schleck pipeline, BRUKER DRX500 nuclear magnetic resonance instrument, Agilent 789013 gas chromatograph were purchased from Germany Agilent, BrukerSmartApex 2CCD X-ray single crystal The diffractometer was purchased from Bruker Company of Germany, and the Perkin Elmer 2400 elemental analyzer was purchased from Perkin Elmer Company of the United States.

Example 1

Preparation of Ferrocenyl Telluride Cuprous Cluster Thermal Catalyst 1 with Efficient Catalytic C-N Coupling (E=Te, n=3):

(1) Synthesis of ferrocenyl telluride ligand L (R=methylene, n=3, E=Te):

Under a nitrogen atmosphere, weigh 1 mmol of ferrocene and dissolve it in 200 ml of tetrahydrofuran, add 6 mmol of n-butyllithium and 1 mmol of tellurium powder in turn, react at room temperature, spin the reaction solution to dryness, and extract with dichloromethane. Purify by silica gel column chromatography and collect Fc ₂ Te ₂ .

Take a 100mL three-neck flask, under nitrogen atmosphere, dissolve 0.5mmol ferrocene ditelluride into absolute ethanol, add 4mmol sodium borohydride and 0.5mmol 1,3-dibromopropane in turn, after the reaction is complete at room temperature, depressurize Distilled and spin-dried, and purified to obtain a yellow solid L.

(2) Synthesis of cuprous cluster 5 by interface method, (R=methylene, m=2, n=3, a=2, b=1, X=I, E=Te):

Weigh the ligand L and dissolve it in dichloromethane, and dissolve the same amount of CuI in acetonitrile. The acetonitrile solution was added dropwise to the upper layer of the dichloromethane solution. After standing for several days, cuprous cluster crystals appeared at the interface. The crystals were picked out for X-ray diffraction test to obtain a single crystal structure. See Figure 1.

Add 2.5mmol of iodobenzene, 0.375mmol of imidazole, 0.5mmol of lithium tert-butoxide, and 10%mmol of cuprous cluster catalyst into a single-necked bottle. Under nitrogen atmosphere, 110 degrees Celsius, seal the reaction for 6 hours; test the reaction stock solution by gas chromatography, The product 1-phenylimidazole concentration was obtained. Yield was obtained after calculation.

Example 2

Add 2.5mmol of iodobenzene, 0.375mmol of imidazole, 0.5mmol of lithium tert-butoxide, and 10% mol of cuprous iodide into the single-necked bottle, under nitrogen atmosphere, 110 degrees Celsius, and seal the reaction for 6 hours; the reaction stock solution is subjected to gas chromatography test, The product 1-phenylimidazole concentration was obtained. Yield was obtained after calculation.

Example 3

In a 10ml single-necked bottle, add 2.5mmol of iodobenzene, 0.375mmol of imidazole, 0.5mmol of lithium tert-butoxide, catalyst 5 (E=Te, n=3, m=2, a=2, b=1, X=I) 10 %mol, under nitrogen atmosphere, 110 degrees centigrade, sealed reaction for 6 hours. After cooling down, the solids were separated and repeated experiments were performed. Repeat three times, carry out the gas phase test on the third reaction stock solution, and calculate the yield. The yields were 99.5%, 91.3%, 89.4%, respectively.

Table three embodiment 1,2,3 catalytic efficiency summary table

frequency 1 2 3 Catalytic efficiency (%) 99.9 Trace 99.5/91.3/89.4

Claims (2)

1. a ferrocene cuprous cluster catalyst for catalyzing C-N coupling reaction, it is characterized in that, described catalyzer uses Se/Te as binding site, forms coordination compound with cuprous, simultaneously copper center and ferrocene center Synergistically acting on catalysis, the ferrocene selenium/tellurite cuprous cluster catalyst includes a compound whose structural formula is as follows: [ _{Cum X m L a} ] _b in: E=Se/Te; n=0 or 1 or 3; a; b; m≥1; X=I or Br; R=-CH ₂ -or or 2. the preparation method of the ferrocene cuprous cluster catalyst of the catalysis C-N coupling reaction of claim 1, is characterized in that, the preparation method of described compound comprises the following steps: (1) Synthesis of ferrocenyl selenium/telluride ligands: Under nitrogen atmosphere, add ferrocene, n-butyllithium, tellurium powder/selenium powder into 200-300ml tetrahydrofuran at a molar ratio of 1:6:1, react at room temperature, spin the reaction solution to dryness, and extract with dichloromethane. Purified by silica gel column chromatography to collect Fc ₂ Te ₂ /Fc ₂ Se ₂ ; Under nitrogen atmosphere, add Fc ₂ Te ₂ /Fc ₂ Se ₂ , sodium borohydride, 1,3-dibromopropane or m-dimethylbromobenzene or p-dimethyl Bromobenzene, after complete reaction at room temperature, was distilled and spin-dried under reduced pressure, and purified to obtain a yellow solid L; (2) Synthesis of cuprous clusters by interface method: Weigh the ferrocenyl propane selenium/telluride ligand L prepared in step (1) and dissolve it in dichloromethane, weigh CuI or CuBr and dissolve it in dry acetonitrile according to the molar ratio of 1:1, and slowly add the acetonitrile solution dropwise To the upper layer of the dichloromethane solution, cuprous cluster crystals appeared at the interface.