Making Dibenzo[a,e]cyclooctene - an Emerging Ligand?
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- čas přidán 29. 09. 2022
- In this video I am synthesizing the ligand dibenzo[a,e[cyclooctene, employing various methods including cold finger sublimation to purify the products!
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Xylene bromination:
www.orgsyn.org/demo.aspx?prep=...
Dibenzo[a,e]cyclooctene synthesis:
www.orgsyn.org/demo.aspx?prep=...
More information about NBS bromination:
chem.libretexts.org/Bookshelv...
en.wikipedia.org/wiki/Wohl%E2...
Synthesis of some complexes with the ligand (where I got structure from):
doi:10.1016/j.ica.2007.12.007 - Věda a technologie
I absolutely love watching vacuum sublimations, seeing the beautiful crystals in this video was a treat !
I really really enjoy watching your videos. You are doing a great job. I appreciate you taking the time to make, edit, upload, and do the reactions. I know it must take up a bunch of your time to do such excellent videos! Ty!! 😀
I'm a spectator chemist with a basic knowledge of chemistry. My interests are wide so I watch it all. I've worked in a material science labs a few times and it left me hungry for understanding. Grunt work, CNC work, specifically ceramics. I worked with brilliant people and learned a lot. I love channels like this that are purely educational. Transition metal chemistry is absolutely fascinating. This was beautiful chemistry!
you're the first chemical youtuber that actually cares about the enviroment and others coming into contact with the chemicals, thank you.
Good job making this videos! Just found out about your channel and the videos I’ve seen we’re already very educative. Keep it up!
Qualities of the videos becomes so excellent!
How are you able to put out so many awesome videos?! Love your work man, I wish I could make stuff this great.
Amazing! Hope you have lots of views for your vídeos! Excellent work and editing
I appreciate the longer run time. Thanks.
first time I see this cold finger apparatus
your videos are amazing
Nicely done. You do good work.
Variants of this, mainly dibenzocyclooctyne groups, are very useful in click chemistry applications! Great video
You honestly could write an entire Chemistry Lab Manual. And I would buy.
Really nice work!
I loved to see the sublimation of your compounds! It is so beautiful! I tried to use this technique in the lab to purified some compounds in the past but it never worked out very well :s.
What about making some organometallic complexes with this ligand? Might get some nice colors like with metallocenes? Mayby some catalysis even?
Please keep going with these incredibly high quality videos.
These are awesome vids man.
I studied organic chem a few years back and this video made me remember all of it, I even predicted the solvants and steps for 2 different synthetic pathways. You get my like sir.
I would love to see some properties or further reactions of it.
I was very impressed that the solid is white, nice video as always mate
You could also try using a green DPSS laser for the radical initiation.
Interesting methods and cool rxn. Also jealous of the chems :)
You continue to impress me with your synthetic ambitions, productivity and fine lab skills! Every video depicts a real challenge. They are educational, but definitely have a good piece of chemical drama. Thank you very much for sharing your amazing chemical adventures! We all appreciate it.
⚗️👍🏻🙂
So cool!!! Great work!!!
Nice vids. Feels like I am watching the methods section of a paper.
This molecule looks fascinating! And today I learned what a ligand is.
The crystals seem to follow that lense shape, forming slopes that end in points.
Two criticisms of this (otherwise excellent) video: first, the mechanism in the dimeriztion of the dibromide almost certainly involves 1,4-elimination of the monolithio species to give 1,2-quinodimethane, which may either dimerize to give the final product directly, or trap a benzylic radical and then cyclize. Second, the potassium tert-butoxide does not remove a hydrogen atom, it removes a proton. in an E2 elimination.
Great video keep it up. I think you sped up the voice over which I think was good
Great vid! How do you get your chemicals? Or is this done in an academic lab?
Can you do the nickel complex out of it? Since Ni(Cod)2 is really prevalent
Is it possible to create a fully planar and aromatic dianion from this, like with plain cyclooctatetraene?
Very interesting process. @13:40 What happens, if you would have 3-4 bromine ligands on the cyclooctocene? Would it hinder the further synthesis and get lost ? Does the benzene get brominated as well, or would it need a catalyst ?
The bromination process is known as "allylic bromination", and it usually leaves di/tri brominated reagents, but it is known to be trace. Also, to brominate the benzene, as you mentioned, needs other catalysts such as FeBr3.
If there are 3-4 bromine attatched to the cyclooctane, elimination of HBr might still happen, but the desired product would be mono-brominated alkene. I believe this could undergo another dehalohydrogenation, or removal of HBr, and yield cyclooctyne ring.
Cyclooctyne could be reduced to cyclooctene using yne->ene reducing agents such as Lindlar catalyst.
Can hexanes be replaced with heptane, CCl3 instead of carbon tet and Sodium be used instead of Li ?
Is it a lithium-halogen exchange if the product is left as a radical instead of R-Li?
how can I mix the RuCl3 compound into this dibenzo solution? can you make a tutorial?
this is an EXTREMELY cool reaction sequence and product ♥♥ made me feel like watching certified hood classic Nurdrage videos again ♥ great work man.
P.S. - what does the product smell like? 🤓
it smells disgusting similar to benzene :(
@@Chemiolis Man, I love the smell of benzene lol. Even though it’s one of those guilty pleasure ones that you just know are giving you cancer 🥴
To remove LiCl, I think water washing might be more straightforward? Add water into THF, then back-extract with DCM.
How did you characterize your product? MP? NMR? IR?
I know you likely dont have access to an NMR but that would elevate these videos to then next level.
Yea I wish 🥲
Does it fluoresce?
Appreciate the mechanisms (when reaction is not straightforward)
After the coupling step with lithium, can you simply do extraction with water (of course removing the Lithium metals first) to remove LiBr?
I think it's possible, I just followed how they did it in the procedure. Perhaps there is a reason they did it this way.
I wonder if this works with cis but-2-ene as well as it does with o-xylene?
if so, it'd be a handy way to make cyclooctratetraene that doesn't involve high-pressure acetylene chemistry
Treating 2-butene with bromine will result in addition of the halogen to the double bond.
Can you make indol 3-acétic acid
any alternatives to carbon tet?
Can chloroform be used instead of CCl4 ?
Wonderful video and clear explanation of the steps and mechanism! Out of curiosity, why was NBS used in the first bromination step of o-xylene? Wouldn’t it be easier to have access to Br radicals over a possible EAS reaction with Br2? Also, in the last step of the reaction, your tBuOK was slightly purple in THF, any reason why that happened?
???? The first bromination is an radical bromination with br2 just like you mentioned, the 2nd is s Wohl-Ziegler-Bromination with NBS
@@lukassorowka2672 NBS is still viable for bromination of toluyl carbons.
@@slimp4644 yeah it is, but I don't get the point of your comment. He didn't use NBS for the first bromination
Bromine is much cheaper than NBS
@@nitrgnlab9400 yeah thats a good point
Has the inner ring a resonance structure similar to that of benzene (pi electrons) ? Or is it "static" ?
no, it's a boat shape rather than flat like benzene - if it were flat, it would have 8 pi electrons and be anti-aromatic (i.e. too unstable to exist)
You said NBS reacts in CCl4 with trace HBr to produce bromine as the active brominating agent. Can you give me a source to read more about that? I thought it was just bromine radicals formed through homolytic cleavage of the N-Br bond, and usually the reaction doesn't work very well unless you freshly recrystallize NBS so it's counter-intuitive to think that the impurities drive the reaction.
Likewise, in my experience I use recrystallized NBS (from boiling water) and DMF or some other cheaper and more friendly solvent than carbon tet. No additives
Once I had some problems with pure white NBS, the reaction didn't start. Then I used 30-year old yellow NBS instead and it worked fine
You should make the equivalent cyclic azobenzene where two of the bridging carbons are nitrogens ;) Would be great to demonstrate photochromism.
Small error, the cyclic azobenzene I'm thinking off has an N=N bridge with a saturated C-C bridge on the other side... so slightly different from the octene here.
Why did you used N-bromosuccinimide, if you could just use bromine instead? Bromine cation could give some side products with phenil rings.
Handling bromine on its own is a lot more unwieldy than NBS.
Can't you get rid of the LiBr with a water wash? Love the video.
P. S. How safe is it to mix tBuOK with ethers in your experience?
I almost always use strong bases in ethereal solvents. Metal hydrides, alkoxides, organolithiums, organosodiums, organomagnesium, organozinc, etc.
No issues. Occasionally, depending on the reaction, I'll avoid ethereal solvents as other reagents will react with (organoborohalides or just borohalides), and opt for a hydrocarbon solvent like toluene.
@@brandonwatson883 thanks for the reply
also to quickly add, yes water washing will remove LiBr, when applicable. This was done with THF which I usually prefer to diethyl ether, but the one issue with THF is that it is miscible with water. Usually if I want to do aqueous work up I'll remove thf, reddisolve in diethyl ether/ethyl acetate/dcm etc before moving forward.
@@brandonwatson883 yeah so this was predominantly DCM at the end, that's why
Great Video! Can someone tell me how to calulate the yield ? Thanks.
The yield is how much product you actually make divided by how much you theoretically expected to make. Then multiplied by 100 to express as percentage.
Where the hell did you get carbon tet??
Nice iStock images
Radical chemistry is so messy. What about the multibrominated groups on the same methyl group? Why is it favoured/disfavored?
the bromine radical yoinking a hydrogen atom needs the proton to come with one electron. bc there is already a bromine on the methyl group, the carbon is more electrophilic, making it harder for the hydrogen radical to be abducted.
A uranium-containing sandwich complex can be made using cyclooctatetraene. I wonder if the same can be done using dibenzo[a,e]cyclooctene?
By the way, thanks for the video, I love aromatic compounds, especially symmetric ones!
I haven’t seen any literature on it, I wonder as well, but I don’t have any uranium compounds sadly ;(
@@Chemiolis I decided to watch this video again, and I was wondering what impurity or impurities caused the dibromoxylene to take on that dark colour? Could it be caused by some of the o-xylene radicals reacting with each other and forming various compounds? Could it be possible oxidation from the air as well?
If you can reduce the cyclooctatetraene you can do that.
38% overall is nothing to scoff at as someone who does this shit for a living. Your technique is already better than most youtube chemists, couple thoughts: The LiBr would've been easily removed by a quick wash with 1M NaCl (20% of organic layer volume) instead of doing so many filtrations. Also brave to one-shot all the material...
What is a google roar distillation? (That’s how the CC translated what you said)
Kugelrohr distillation, done with a Kugelrohr apparatus
@@Chemiolis thank you
How did your hands on carbon tet?
From old fire extinguishers (see old vid)
The forbidden sour lollipop
Wow! How did you get CCl4?
Just buy it I have some too
Why are cycles still drawn with double bonds when it's known that it's just a common electron cloud between all carbons? At least in benzene.
why not use NBS for the first step as well?
Bromine is much cheaper
Why is the distilled thf pink?
The flask I used as a receiver was the dirty reaction flask, likely something that was left behind.
Yoo this guy has an access to carbon tet!
Chemloli manage to recreate ligma. very nice.
That stir bar be my pills rn. (i have Tonsillitis)
cool
Nilered vibe🙌
Metal complex chemistry is some black magic to me. Only orgo.
DBCOD is great. Dibromoxylane is a lacrimogenic nightmare
I experienced it with my own eyes, burned like I'd imagine hell for 1-2 hours
I’m constantly amazed at how intelligent humans are.
прекурсия к амитриптилину всеми любимому и проверенному средству от икоты🙏☝️
hexagons are the bestagons
Why do all CZcams chemists drop the stirrer bar into the flask with no care for the glass flask -_-
It’s an outdated ‘rule’. Magnetic stir bars used to be a lot heavier because they contained a different magnet. Nowadays the stir bar has a lighter magnet inside and can’t break glass.
@@Chemiolis It depends on a size of the stirfish. I don't want to drop an AA battery size bar into a 2 l RBF(
@@Chemiolis of course it can. Last winter I had to clean my hood for all day long after dropping the stir bar into the reaction mixture (yep, it was a stupid idea, but I thought the precipitate at the bottom of the flask would amortize it. No it didn't). Wish I could attach the photos.
Casual carbon tet
PAHs always make me nervous.
Mmmmm carbon tet
Can't you just wash out the libr? Seems more logical to me ...
carbon tet! carbon tet!!!!!
Boop
Drinking game: Shot every time short path vacuum distillation is mentioned.
The ending was a bit... abrupt....
Я наверно здесь один русский
Нет
That looks like cancer.
Reminds me of this: en.wikipedia.org/wiki/Cyclooctadiene_rhodium_chloride_dimer
benzene: 🆑orinated
o-xylene: 🅱rominated
fingers: Nitrated
Yep,it's chemistry time 😎