Into Unscientific

Five days later.

A medicinal chemistry laboratory on the fourth floor of the University of Science and Technology Medical Center Building.

At this moment, Xu Yun was wearing a pure cotton lab coat and standing on the console, in front of him stood six men and women of different heights.

"Several juniors and juniors, since everyone is here, I will briefly talk about half a chapter first. Cough cough, say a few words."

Xu Yun raised a stack of bound documents in his hand, and his eyes quickly swept over the people in front of him:

"Yesterday morning, I got the project approval receipt for the project. Now that the procedures, venue and personnel have been completed, our project team has been established.

Our project team does not have a mentor to lead the team. I am the applicant and the first person in charge. The use period of the laboratory is two weeks. The records of participation in the research will be registered in your files. Having past experience should be somewhat helpful to everyone in the future. "

Hearing this, out of the six people in front of them, there was an uncontrollable joy on the faces of two of them.

As one of the members of C9, the University of Science and Technology of China has an annual research and development expenditure of about tens of billions, and it is almost nine or ten in China.

This figure may seem large, but after deducting a series of projects such as the 973 Program, the 863 Program, the National Science and Technology Support Program, and the International Science and Technology Cooperation and Exchange Project, the funds and quotas distributed to each hospital are far from what they seem. big.

Afterwards, some big names took a point, and there was still funds left, but there were not many places left for high-quality projects.

Many graduate students have been busy for one or two semesters, and they may not be able to get involved in the corners of large-scale projects. They can only be silently manipulated by their tutors like donkeys.

Therefore, when Xu Yun came to the door with the proposal proposal for Tian Liangwei's auxiliary project, several bitter graduate students immediately nodded their heads. Chinese people.

To put it bluntly, if you have participated in such a level of project team, no matter whether you can produce results in the end, when you declare your salary after graduation, you can ask for at least 500 yuan more a month!

Then Xu Yun paused and continued:

"The goal of our project is very simple. It is to try to synthesize a new substance from pheromone and the third-generation imidacloprid to verify and explore the direction of the fourth-generation imidacloprid. The ultimate goal is"

As soon as the words fell, several juniors and juniors shouted together:

"Destroy Xiaoqiang!"

After finishing speaking, everyone laughed happily.

Amidst the laughter, a girl with short hair raised her hand and asked Xu Yun curiously:

"Senior, why do you have such a big grudge against cockroaches?"

Xu Yun glanced at her lightly. This girl is called Tang Yiqiu. She is a senior student in college with good grades and reputation:

".To me it's a sad story, but it would make you guys happy to say it, so I refuse to answer."

After he finished speaking, he raised the document in his hand, and the pages rattled in the air:

"Okay, let's gossip here, we have limited time, everyone test the gas mask and organic vapor filter box, put on the protective skirts, and start the test in fifteen minutes!"

Then he gave Qiu Sheng a look:

"Old Qiu, check the machine and switch, and I will distribute the materials."

Qiu Sheng nodded:

"clear."

Fifteen minutes later, everything was ready.

The main experimental reagents used by Xu Yun et al. are 2-phenylpyridine, 4-hydroxymethylphenylboronic acid, 2-naphthaleneboronic acid, 3-furanboronic acid, 3-benzothiopheneboronic acid, N-phenylpyrazole, Benzoquinoline, [Ru(p-cymene)2Cl2]2 and so on.

In addition, there are more than thirty kinds of reagents including 2-bromopyridine, 2-bromo-4-chloropyridine, THF, DMF (N,N-dimethylformamide), DMSO, 1,4-dioxane, etc. (I wrote the details in the author's words)

At the same time, the rest of the people also stood in their positions one by one.

"If you want to combine pheromones with imidacloprid, you must first cyclize CH3. I plan to complete the hydrogenation reduction reaction through the coupling of epoxy terminal alkyne and 1-bromo-2-pentyne."

On the console, while expressing his thoughts, Xu Yun made a mistake to a tool man, and the junior said:

"Li Yan, this task is entrusted to you."

"clear!"

The Li Yan that Xu Yun was talking about was a graduate student, 24 years old this year, with a cropped haircut, and immediately started to operate upon hearing this.

At the same time, Xu Yun looked at Tang Yiqiu again:

"Little Tang, you are in charge of following up, trying to capture the optically active fragment of epoxy sulfonate!"

"clear!"

well known.

Under the catalysis of L-(+)-diisopropyl tartrate and tetraisopropyl titanium oxide, allyl alcohol will undergo Sharpless asymmetric epoxidation reaction to obtain (2S,3R)-2,3-epoxy- 1-tetradecyl alcohol.

Epoxy alcohol (2S, 3R)-9 is ring-opened by p-toluenesulfonylation and perchloric acid, and the absolute configuration of carbon atom 3 is reversed from R to S to obtain (2S, 3S)-p-toluenesulfonic acid 2,3 -Dihydroxy-1-tetradecyl alcohol ester; then through potassium carbonate ring closure and p-toluenesulfonylation, you can get (2S, 3S)-p-toluenesulfonic acid 1,2-epoxy-3-tetradecyl Alcohol esters, the yield can reach 89%.

Very simple and very easy to understand.

A few minutes later, Tang Yiqiu raised her hand again, but this time she didn't ask why Xu Yun wanted to kill cockroaches:

"Senior, epoxy sulfonate has captured it!"

"Very good, how much is ee worth?"

"The epoxy alcohol and dinitrobenzoyl chloride are still reacting during the determination. Oh, it came out, 93%!"

Xu Yun couldn't help but heaved a sigh of relief when he heard that.

The so-called ee value refers to the enantiomeric excess. The theoretical ee value of the chiral epoxy sulfonate is 90%, and the 93% measured by Xiao Tang is above the level line. Right now, it is the first small step of success.

After completing the synthesis of key optically active intermediates, the next step is to study the asymmetric synthesis of target pheromones.

The operation of this step is to react the epoxy sulfonate with trimethylsilyl acetylene first, the epoxy ring-opening occurs, and then the ring-closing and de-TMS are treated with potassium carbonate to obtain (4S,5R)-4,5- Epoxy-1-hexadecyne, and the yield of this step is .

60%.

That's right, the first step is 89%, and the second step is 60%.

Yields almost halved.

This is a very common situation in biochemistry. The yield decreases as the process progresses, from 90% to 60%, and then 30%.

After Qibahuan, the yield of abnormal compounds may even be only single digits.

So why do you say that scientific research burns money? In the ten minutes since Xu Yun and his team started, including machine wear and tear, they have already spent at least 1,000 yuan, which is a whole leader.

The preparation of 5-epoxy-1-hexadecyne went well, just when Xu Yun and others were going to take another step forward

I saw another graduate student in charge of nucleophilic substitution suddenly let out an 'ah' and sighed:

"Senior, the nucleophilic substitution reaction failed."

All experimental reagents:

2-Phenylpyridine, p-methylphenylboronic acid, p-vinylphenylboronic acid, 4-hydroxymethylphenylboronic acid, 4-vinylphenylboronic acid, 2-naphthaleneboronic acid, 3-furanboronic acid, 3-benzothiopheneboronic acid, N-phenylpyrazole, benzoquinoline, [Ru(p-cymene)2Cl2]2.

and paraformaldehyde, DCM (dichloromethane), DCE, CHCl3 (chloroform), MeOH (methanol), EtOH (ethanol), Ac OEt (ethyl acetate), THF (tetrahydrofuran), DMF (N,N- Dimethylformamide), DMSO (dimethyl sulfoxide), 1,4-dioxane (1,4-dioxane), CH3CN (acetonitrile), n-hexane (n-hexane) and toluene (toluene), etc. wait.

2-bromopyridine, 2-bromo-4-chloropyridine, 2-bromo-3-methylpyridine, 2-bromo-5-methylpyridine, 2-bromo-3-fluoropyridine,