CN113735673B - Method for catalyzing cyclopropanation reaction of olefin by acidic molecular sieve - Google Patents

Abstract

The invention discloses a method for catalyzing cyclopropanation of olefin by an acidic molecular sieve, which comprises the following steps: firstly, mixing an acidic molecular sieve catalyst and a zinc carbene compound at-30-10 ℃ in a nitrogen atmosphere; secondly, adding raw material olefin into the reaction system of the first step for reaction; and thirdly, separating and purifying the reaction product obtained in the second step to obtain the cyclopropane compound. The invention adopts the acidic molecular sieve catalyst to carry out cyclopropanation reaction on the olefin, and has high catalyst activity, high olefin conversion rate and high product yield; and the molecular sieve can be recycled, so that the production cost is reduced.

Description

Method for catalyzing cyclopropanation of olefin by acidic molecular sieve

technical field

The invention relates to the technical field of cyclopropanation of olefins, in particular to a method for cyclopropanation of olefins catalyzed by an acidic molecular sieve catalyst.

Background technique

With the rapid development of the aerospace industry, higher requirements are also placed on the performance of aerospace fuels. It is necessary to prepare aerospace fuels with high specific impulse and high energy density. The specific impulse and density of the fuel can be effectively improved by introducing a high tension ring structure into the fuel molecule. The Simmons-Smith reaction is widely used in the synthesis of various cyclopropane compounds, and the Simmons-Smith reaction is one of the effective means to introduce high-tension three-membered ring structures into fuel molecules.

Acid如CF₃COOH或CCl₃COOH等，或Lewis Acid如TiCl₄、AlCl₃或ZnCl₂等，可以改变R基团结构，提高卡宾体的反应活性，促进环丙烷化反应的进行。然而

Acid或Lewis Acid在反应中不断被消耗，无法回收，造成大量浪费。In the Simmons-Smith reaction, alkenes and carbene bodies undergo cyclopropanation and are converted into saturated alkanes. The involved carbene bodies can be represented by the formula RZnCH ₂ X, where R is an organic group and X is a halogen atom; The structure of the R group can change the activity of the carbene. The study found that adding organic

Acids such as CF ₃ COOH or CCl ₃ COOH, or Lewis Acids such as TiCl ₄ , AlCl ₃ or ZnCl ₂ , etc., can change the structure of the R group, improve the reactivity of the carbene, and promote the cyclopropanation reaction. However

Acid or Lewis Acid is continuously consumed in the reaction and cannot be recycled, resulting in a lot of waste.

The present invention has been proposed to solve the above-mentioned problems.

SUMMARY OF THE INVENTION

Acid或Lewis Acid不断被消耗、无法回收的问题，本发明提供一种可循环使用的酸性分子筛催化剂催化烯烃环丙烷化反应的方法。To solve the existing technology

Acid or Lewis Acid is continuously consumed and cannot be recovered. The present invention provides a method for catalyzing cyclopropanation of olefin by a recyclable acidic molecular sieve catalyst.

The technical scheme of the present invention is as follows:

A method for the cyclopropanation of olefins catalyzed by an acidic molecular sieve, comprising the following steps: (1) mixing an acidic molecular sieve catalyst and a zinc carbene in a nitrogen atmosphere at -30°C to 10°C; (2) adding raw materials to the reaction system in step (1) The olefin is reacted; ③ the reaction product of the separation and purification step ② is obtained to obtain a cyclopropanation product.

Preferably, the acidic molecular sieve catalyst is one or more of HZSM-5, Hβ, HY, and Al-MCM-41.

Preferably, the dosage of the acidic molecular sieve catalyst is 10-70 wt% of the raw olefin.

Preferably, the zinc-based carbene is EtZnCH ₂ I.

Preferably, the ratio of the raw olefin to the zinc-based carbene is 1:(1-6).

Preferably, the olefin is one or more of myrcene, α-pinene, β-pinene, dicyclopentadiene, norbornene and norbornadiene.

Beneficial effects of the present invention:

1. The present invention adopts acidic molecular sieve as a catalyst for the cyclopropanation reaction of olefins for the first time. The catalyst has high activity, and the olefin conversion rate and product yield are both higher than the catalytic effect of a homogeneous organic acid.

2. The acidic molecular sieve catalyst of the present invention can be recycled and used, and the activity of the catalyst is almost not reduced after being recycled and used for ten times. Production costs are greatly reduced.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. If no specific technology or condition is indicated in the examples, the technology or condition described in the literature in the field or the product specification is used. The reagents or instruments used without the manufacturer's indication are conventional products that can be obtained through purchase.

Example 1: Cyclopropanation of olefins catalyzed by acidic molecular sieves

(1) First, calcinate the HZSM-5 molecular sieve at 550 ° C for 5 hours to remove the impurities it adsorbs;

( ₂ ) Add 30 mL of diethylzinc solution and 30 mL of dichloromethane solvent to the three-necked jacketed flask at -20°C and N atmosphere;

(3) take by weighing the HZSM-5 molecular sieve after 0.594g roasting, join in the solution of step (2) under mechanical stirring, then slowly drip 15mL dichloromethane solvent therein, react 20min;

(4) Measure 15mL of dichloromethane solvent, add 2.470mL of diiodomethane reagent to it and mix it uniformly; then this solution is added dropwise to the reaction solution of step (3), reacted for 20min;

(5) Measure 15mL of dichloromethane solvent, add 2.020mL of dicyclopentadiene reaction raw material to it, slowly drop it into step (4) reaction solution, and react at 25°C for 4 hours;

(6) after the reaction finishes, add saturated ammonium chloride solution in the reaction solution, continue stirring 5 minutes; Then separate organic phase and water phase, organic phase is washed successively with deionized water, saturated sodium chloride solution, with anhydrous sulfuric acid The magnesium is dried; the product composition is finally analyzed by gas chromatography. The yield of product cyclopropanation product was 89.3%.

The HZSM-5 molecular sieves reacted in Example 1 were recovered by filtration, and were reused 10 times using the same reaction conditions as in Example 1. The reaction results are listed in Table 1.

Table 1 Catalytic effect of HZSM-5 molecular sieve used continuously for 10 times

repeat times Product yield/% 2 88.8 3 89.5 4 86.8 5 84.9 6 85.3 7 86.1 8 85.8 9 83.9 10 84.4 11 85.6

It can be seen from Table 1 that the acid molecular sieve HZSM-5 catalyst is recycled and reused 10 times, and the product yield decreases very little.

Examples 2-8

The reaction steps of Examples 2-8 are the same as those of Example 1, except that the reaction raw materials, catalysts or reaction conditions are different, as shown in Table 2.

Table 2 Examples 2-8

It can be seen from Table 2 that the use of acidic molecular sieves as the catalyst for the cyclopropanation of olefins has high catalyst activity, high olefin conversion and product yield, and the cyclopropane compound yield is above 85%.

Although specific embodiments of the invention have been described herein for purposes of illustration, various changes in detail will be apparent to those skilled in the art without departing from the invention.

Claims (3)

1. a method for acidic molecular sieve catalysis olefin cyclopropanation, is characterized in that, comprises the steps: 1. in-20 ℃ and nitrogen atmosphere, acid molecular sieve catalyst and zinc carbene are mixed; 2. to the reaction system of step 1. Add the raw material olefin to react; 3) the reaction product of separation and purification step 2 is to obtain a cyclopropanation product; the acidic molecular sieve catalyst is one or more of HZSM-5, Hβ, HY, and Al-MCM-41; Described zinc carbene is EtZnCH ₂ I; The mixing steps of the acidic molecular sieve catalyst and the zinc carbene are: (1) First, calcinate the acidic molecular sieve at 550 °C for 5 hours to remove the impurities adsorbed by it; (2) Add 30 mL of diethylzinc solution and 30 mL of dichloromethane solvent to a three-necked jacketed flask at -20 °C and _N2 atmosphere; (3) Weigh 0.594 g of the calcined acidic molecular sieve, add it to the solution of step (2) under mechanical stirring, then slowly add 15 mL of dichloromethane solvent dropwise to it, and react for 20 min; (4) Measure 15 mL of dichloromethane solvent, add 2.470 mL of diiodomethane reagent to it and mix evenly; then add the solution dropwise to the reaction solution in step (3), and react for 20 min. 2 . The method according to claim 1 , wherein the amount of the acidic molecular sieve catalyst used is 10-70 wt % of the raw material olefin. 3 . 3. method according to claim 1, is characterized in that, described raw material olefin is a kind of in myrcene, α-pinene, β-pinene, dicyclopentadiene, norbornene, norbornadiene or several.