Nef Reaction (Introduction to Umpolung Chemistry)

[@glennpearson9348]

Umpolung?! Saying the word reminds of the German bands I used to listen to in Bavaria during Oktoberfest. This one went way over my head, Professor Dave, but I enjoyed it all the same. More great science content from one of the best in the business.

[@neuropsidoc4670]

Now we got a Nef understanding.

[@michaelathens953]

Hey I remember this one. Haven't thought about the nef reaction in ages, cool refresher!

[@BradSchmor]

Another example of umpolung with nitroalkyl groups is the Henry reaction. If done under dehydrating conditions, the resultant nitroalkene is an excellent Michael acceptor and allows you to build up the chain quickly. Optimizing the Henry condensation can be seriously challenging sometimes, though.

[@Aero_JJ]

Thank you professor Dave Ghrol

[@markshort9098]

I thought you were going to say umpolumpa for a second 🤣

[@kd1419]

Hi professor, would this nitronate-carbonyl followed by nef reaction approach be preferred over the dithiane umpolung? i would think that, even though both would achieve the same 1,4-diketone, the dithiane approach would require lesser steps and give greater yields? i am aware that dithiane would require the handling of mecuric salts. may i know what are your thoughts?

[@galileog8945]

If you have a carbonyl, you can achieve umpolung by converting it to dithiane (or cyanohydrin), if you have a nitroalkane, you use that. Very simple.

[@Bunny99s]

As a trained electro-mechanic and now a software and games programmer, I have to say when it comes to chemistry I'm certainly trapped in the "valley of despair" :) Whenever you think you went up the slope of enlightenment just a little bit, you just slip down again to the bottom when a new video of Dave comes out :D. Nevertheless, even though I understood only 5%, I find it humbling to see what people have come up with and what they have figured out about our world. My former physics teacher always made fun of chemistry as it's just a subset of particle phyiscs. While this is technically true, it kind of missed the point. While phyiscs can explain how particles interact with each other, it's not suitable to reason about material properties and macro scale effects. It's like looking at individual bit in computer memory, seeing 1s and 0s and trying to reason about the story of the RPG game that is currently running. That would be pretty stupid. Drawing programming analogies, I would say when physics could be compared to machine code / assembler, chemistry would be a specialized high level language. All that happens in chemistry has its basis in plain physics, but it's much easier to work in the higher level language. Isn't it amazing what the internet can provide us? Every piece of information and knowledge is just some clicks away. Yes, there is a huge potential for misinformation spreading (antivax, flatearth, anit-science, anit-government, alternative medicine and even black people voting trump and denying racism), though I hope in the long run people understand the value of the scientific method... if they only would understand it. Even in my own family there always was a bit esoteric involved (like homeopathy). However since the corona pandemie they have gone full force anti establishment, anti vax and world conspiracy. At the moment I realised there's no hope to "convince" them or change their mind. They trapped themselfs in several echo chambers which is really sad. I just hope time will solve some of the issues. Though with the Ukraine war things are not getting better... Anyways, keep up the great work. Getting some insight into the work of other fields is just great. Perfect place to accumulate some dangerous sciolism :)

[@jeromebirth2693]

Have any of these chemical reactions been tested on the ISS in zero gravity to see if it is easier, or more difficult to net results?

[@ProfessorDaveExplains]

Doing chemistry in space would be extremely difficult and impractical with no apparent benefit or purpose.

[@BradSchmor]

​@@ProfessorDaveExplains actually, I can think of one. I know this sounds like something centuries in the future, but Boston U is setting up flow systems for the ISS to test this concept. Imagine a crew en route to Mars needs a specific chemical for some reason - perhaps a drug to treat an unforeseen illness, such as seizure medication. Having the ability to program robots to synthesize at least some things via instructions beamed from earth (and tested first on something closer by like the ISS) would be very beneficial. And yes I understand that the dizzyingly complex inventory of reagents needed to be somehow stored and potentially used sounds prohibitive. Obviously the lack of gravity would probably necessitate reactions to run entirely in flow-type systems, or some sort of gravity simulant (such as a slow-running centrifuge).

[@ProfessorDaveExplains]

I just think it would be dramatically easier to bring small amounts of every drug that could conceivably be needed with you. Tiny pills vs. big complicated machinery.

[@BradSchmor]

@@ProfessorDaveExplainsI'm thinking that's probably true. I was just pointing out that this idea is in the exploratory phase.

[@banu6091]

How to turn off incandescent torch light in present of which chemical reaction

[@Messmer_da_Impaler]

Hey, i just wanna know if you think kurgzgesagt are a good source of information or not

[@ProfessorDaveExplains]

Yeah I'm pretty sure they're solid.

[@Messmer_da_Impaler]

@@ProfessorDaveExplains ok, thanks

[@Sleepyboiwonder]

Go Matadors!!!

[@Mathew7245]

omg how many named reactions are there in organic chemistry

[@neuropsidoc4670]

More than you have time.

[@Mathew7245]

@@neuropsidoc4670 indeed

[@jbirdmax]

Isn’t umpolung what you get when you vape too much? 😂

[@tinfoilfreak]

My tin foil knows nothing of this.

[@abhay3016]

Hey, professor hope you are doing good as always, I already owe you a lot, however, a small request, I implore you to make a detailed playlist of videos, of ECOLOGY as there aren't many good sources to cover this portion.

[@ProfessorDaveExplains]

That's coming soon!

[@-JA-]

👏👍

[@HardToBeAPoopGod]

i'm German and didn't even read 'Umpolung' as a German word LOL i read it as some like, native Canadian last name

[@BenStJohn-rm3mp]

Small note: I'm pretty sure (given the German) it should be pronounced "oom-POLE-ung"

[@livomahmud6791]

First comment 🙋‍♀️

[@markshort9098]

🏆

[@Ilanos1030]

Me who did not understand a bit 😂