How to get "amine" full sense?Look at the selective synthesis of functional amine

"Anshongxia has millions of rooms, and the cold people in the world are full of face." This poem really expresses the beautiful ideal and hope of the poet's hope that the poor people in the world can live a stable life, and express the broad minds and the world's hearts that the poet cares about the suffering of the people's livelihood.

The ancients had the ideal ambitions of the ancients who worried about the country and the people, and today there are people who dedicate their youth and strength to realize the prosperity and prosperity of the country.

For current chemists, they often use or synthesize various organic compounds, and they know the "spleen" of these chemicals (the structure, materialization, toxicity, and functional application of organic compounds). Among them, one of the most interested in chemists is organic amine.

What is organic amine?

Figure: amino group, composed of one nitrogen atom and two hydrogen atoms, chemical formula is -NH2

Organic amine generally refers to organic amine compounds generated by the chemical reactions of organic substances and ammonia. Seven categories. Depending on the nitrogen of organic amine, the difference in the number of bases can also be divided into pupamine, bell, and uncle.

The simplest and most well -known organic amine is urea. It is also known as carbamide, and its chemical formula is CH4N2O. It is an organic compound composed of carbon, nitrogen, oxygen, and hydrogen. It is a white crystal.

As a neutral fertilizer, urea is suitable for various soils and plants, and it is currently a kind of chemical nitrogen fertilizer with a large amount.

In addition, organic amine is also an important type of chemical intermediate, which is widely used in the synthesis of fine chemical products such as pesticide medicine, cosmetics, biological active natural products, and functional materials.

Chemist's pursuit of "amine" fullness

With the development of the chemical industry, the demand for organic amine in China has increased sharply. At present, the production capacity of organic amine has exceeded 1 million tons, and the production of organic amine compounds is mainly concentrated in developed countries. The domestic organic amine research market potential is huge.

In addition, organic amine compounds also play an important role in people's social production and life and health.

Therefore, many chemists focus on the development of a series of economically efficient and simple and green synthesis methods to prepare organic amine compounds, create a new type of organic amine structure that people may need in people's future social production, and further realize the industry of organic amine compounds. Large -scale synthesis and further derivative applications.

(Picture source: veer)

Through the synthesis and transformation of organic amine, it provides convenience and guarantee for people's clothing, food, housing, life and health, so as to create a better material life for humans, increase people's "amine" full sense and happiness. This is the ideal of many chemists. Pursue.

Synthesis development of organic amine

When it comes to the synthesis of organic amine, I have to mention the synthesis of urea. Why?

Because the synthesis of urea not only has great industrial significance, it also represents the origin of organic chemistry.

The word "organic chemistry" was first proposed by Beltlis in 1806. It was named as an opposite of "inorganic chemistry". At the beginning of the 19th century, many chemists believed that the organic compounds that could only be produced in the biological body could not be synthesized by inorganic compounds.

In 1824, German chemist Friedrich Welle was made of oxalic acid with oxygenic acid through oleic acid. In 1828, he accidentally used heating methods to turn cyanide into urea. Both cyanide and ammonium cyanide are inorganic compounds, and both oxalic acid and urea are organic compounds. As a result, in 1828, Weiller published a paper on "Artificially made in urea", which marked the beginning of organic chemistry.

Fertilizer (Picture Source: Veer Gallery)

Modern industries produce urea with ammonia and carbon dioxide as raw materials. The first factory in the world was put into operation by Germany's French company in 1922 in OPPAU, using heat -hybrid compression cycle.

In addition to the simplest organic amine -urea, the industrial scale synthesis of other types of organic amine has also developed.

At present, the preparation methods of organic amine compounds in the industry are mainly alcohol, alkamine to alkylated alkylated ammonia/amine, aldehydes, and restoration of 腈. However, the raw materials of these methods need to be synthesized, the operation steps are complicated, the environmental pollution environment, and the reaction conditions are harsh, and the required temperature and pressure are greater.

Therefore, at the level of science and industrial production, chemists need to develop and create more efficient, simple, green economy, and in line with the principles of sustainable development.

How to "one step" synthesize organic amine?

Since it is necessary to develop more efficient organic amine synthetic routes, it is of great significance to "one step" to synthesize amine.

"Olefin's hydrogen amine methylated" is such a typical series of cyclical reaction. Essence

The atomic utilization rate of this reaction is as high as 100%, which makes full use of the toxic exhaust gas carbon dioxide produced in the industry, reducing the harm of solid waste to the environment during the reaction process, and the concept of green chemistry and the requirements of sustainable development.

Picture source: Author self -made

In the olefin -based hydrogenia, the catalyst is inseparable from the catalyst. The catalyst is the key core of almost all organic reactions.

At present, in the hydrogen amine methylated reaction, the reaction efficiency and regional selectivity of the average catalyst (in the reaction process will generate direct -chain amine and branched amine) can achieve good results, but there are difficulties in the existence of tadpoles and precious metals. The problem. Although the problem of the loss of metals and precious metals in the two -phase catalytic process has been solved to a certain extent, the reaction efficiency is low. Although multi -phase catalysts can also be reused to a certain extent, they can be reused to a certain extent, but the reaction activity and regional selectivity of the product organic amine are difficult to ensure.

Therefore, how to design and develop efficient multi -phase catalysts for hydrogen amine methylation reactions, thereby obtaining excellent yield, regional selectivity, and reusable catalysts.

Recently, the Lanzhou Institute of Chemical Physics of the Chinese Academy of Sciences and the key laboratories of the selection of nationally oxidized countries have multi -phase -phase -of -phase combined catalytic research group designed a new type of polymer catalyst.

The polymer catalyst is made of two-toothed ligand DPMPHOS and a single-toothed ligand P-3VPPH3 as a cluster monomer, and used in the process of preparing the polymer to bury the active metal 铑CPOL-DPMPHOS & P-3VPPH3.

(Picture source: Chemical Communications)

In the polymer catalyst, the metal cricket exists in the form of a single atom (the spherical electron microscopic diagram of the polymer catalyst, each white point represents an active single atomic position).

Polycramotic electron microscopy diagram (Source: Chemical Communications)

This catalyst shows good reaction performance in the reaction of the hydrogen amine hydrogen amine hydrogen amine. The reaction yield is as high as 90%and the direct -chain amine selectivity is as high as 99%. There is a good substrate universality, and the loss of active metal tadpoles is not found during the reuse of the polymer catalyst.

Compared with the currently reported multi -phase catalyst, the polymer catalyst shows more excellent activity and regional selectivity.

(Picture source: Chemical Communications)

So why is the polymer catalyst have excellent regional selectivity?

There are two main reasons for the following. First, the polymer catalyst has a multi -level hole structure (different sizes of the melody channel). Chain amine and reduce the genetic rate of chain amine, thereby increasing the regional selectivity of the reaction.

The second is that the bipotransmid ligand DPMPHOS in the polymer catalyst can form a beneficial supporting configuration with the active metal 铑, which has also promoted the regional selectivity improvement.

In short, the coordination of the spatial limit of the multi -level tract in the polymer catalyst and the coordination of the coordination of the two -toothed ligands promotes the selectivity of the hydrogen amine methylation reaction area.

Although the polymer catalyst has many advantages, it is still in the laboratory research stage, and it is still very far away from the industrial application, and there are some shortcomings itself, such as high catalyst preparation costs.

However, the development of the polymer catalyst can promote the development of organic amine synthesis to a certain extent, and inspires the catalyst of more efficient and practical synthetic organic amine.

Conclusion

A meaningful scientific research is a long difficult and twisting process from laboratory to industrial applications and serving the public. It requires many scientists and scientific research teams to study and struggle for ten years. This is also the value of scientific research and scientists.

As academicians of Chinese nuclear physicists and "two bombs and one star" Yuan Xun Qian Qian said, "the scientific experience is a very twisty and difficult road." The development and powerful of a country are inseparable from scientific innovation, and an important and valuable scientific research results are naturally inseparable from the hard work of excellent scientific researchers.

The national rejuvenation journey is far away, and the people are not idle. I sincerely hope that this article can enable more people to gain some knowledge from science popularization, and be more determined to have the ideals and beliefs of young people who are interested in scientific research in the future, and then contribute to the development of society and the prosperity of the motherland.

Produced: Popular Science China

Author: Zhao Kang, Wang Hongli, Cui Xinjiang, Shi Feng (Institute of Lanzhou Chemical Physics in the Chinese Academy of Sciences)

Producer: China Science Popularization Expo

Edit: Wang Tingting

references:

1. https://baike.baidu.com/

2. http://wikipedia.moesalih.com/

3. https://pubs.rsc.org/en/content/articlelanding/2022/cc/d2cc02469a

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