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@tranlequoclinh2951 10 күн бұрын
Should we worry about hydrolysis of amide when using NaOH after thiourea
@CasualChemistry 10 күн бұрын
Not really - the amide hydrolysis is way slower. We can use the hydroxide without high temperature too to minimise problems.
@arminmh5427 21 күн бұрын
Your explanations are very great. You clarified the concept of asymmetric synthesis concisely.
@CasualChemistry 19 күн бұрын
🙂 Thanks - glad the video was helpful
@mohamedafrah7270 22 күн бұрын
I am really struggling to solve this problem. Could you give me the key to solve it (The Haber-Bosch process is the main industrial procedure to produce ammonia. Hydrogen reacts with nitrogen (derived from air) to form ammonia, in the presence of a heterogenous catalyst (e.g. Fe, Ru compounds). Assume that: 1) the reaction is carried out in gas phase in a closed reactor of volume V, kept at constant temperature T and pressure p 2) the gas mixture is perfect at all temperatures and pressures 3) initially the system is prepared with nN0 moles of nitrogen and nH0 moles of hydrogen. Perform a purely thermodynamic analysis to determine the amount of each species in the system at equilibrium. Solve, discussing your methods, data and approximations, the following problems: I. evaluate and plot the equilibrium constant as a function of temperature; assume constant but not zero thermal capacities II. suppose that an industrial plant works at T=300 K, p=150 bar, and at equilibrium the reactor contains 30 tons of ammonia: what mass of hydrogen is initially introduced, assuming that nitrogen and hydrogen are initially in stoichiometric ratio, i.e. nN0 / nH0 =1/3?)
@CasualChemistry 10 күн бұрын
Sorry - I can’t do exam question help as part of this channel
@rachananarayan4507 25 күн бұрын
You made the synthesis super easy. looking for more similar videos.
@CasualChemistry 24 күн бұрын
🙂 Glad it was helpful - hope you find some more you like on my channel
@triple_gem_shining Ай бұрын
Thats a beautiful reaction.
@CasualChemistry Ай бұрын
Usually works well too which is definitely a bonus
@finno-px6of Ай бұрын
Great video, thanks!
@CasualChemistry Ай бұрын
You’re welcome 🙂
@beatrice1645 Ай бұрын
how can i synthesize cyclopropane with metal catalysis?
@CasualChemistry Ай бұрын
Making the rhodium carbenoid from a diazo starting material and reacting with an alkene is a traditional method for this
@fakhernticha Ай бұрын
reference pls, Super interesting !
@CasualChemistry Ай бұрын
Thanks :) Whoops - I've just put a couple of references in the description (I must've forgotten to do that). One of the original papers and one that is most connected to the example that I've given in the video.
@fakhernticha Ай бұрын
@CasualChemistry Thanks !!
@cedt3468 Ай бұрын
Wouldn't that be more efficient to create the bond between the pyrazole moeity and the benzisoxazole using N-arylation (Chan-Lam or Buchwald) ? That would be more convergent and would by-pass the problem of regioselectivity as hydrazine without substituant can be used to create the pyrazole ring.
@cedt3468 Ай бұрын
Amazing content by the way. Very useful and well explained
@CasualChemistry Ай бұрын
Thanks 🙂
@CasualChemistry Ай бұрын
Fair - I’m sure there are other routes for sure. I’ve stayed with a very classical one here that was used on an industrial scale synthesis in reality. I’ve tried to justify the logic but I’ll admit the route might also be preferred cos of ease of purification stages etc just as much as convergency/step-count.
@cedt3468 Ай бұрын
@CasualChemistry That makes sense! Thank you for taking the time to reply and give additional details. Very appreciated!
@somebodyelse393 Ай бұрын
hey quick question, why is it that on the narasaka reaction, because we have two sp2 carbons the lowest conformation is going to be the half chair? thank you awesome video!
@CasualChemistry Ай бұрын
No worries 🙂 well those 2 sp2 carbons force the next 2 either side into the plane too. So essentially 4 of the atoms in the ring are co-planar at this point. The transition state essentially is quite early in the reaction journey across the energy profile so this model is aiming to reflect that.
@somebodyelse393 Ай бұрын
@@CasualChemistry ohhh thanks for the quick answer sir. its been also difficult for me to understand why in this case it is favoured the attack from the bottom. in the video you said its because the attack from the botton gives us a chair conf while the one from above is a twisted chair but its kind hard to visualise this. cant it be just because the OH is to the from, while having a ring with both oxygens, since one O is to the front the other tends to be that way as well, giving us both OH to the front? its cause I need to do a presentation about this and if I could explain this that way would be easier than using the chairs ahaha thank you very much once again!
@CasualChemistry Ай бұрын
I’m afraid you need to keep the arguments consistent with each other. This reaction is irreversible, so kinetic control is important (what the product is is irrelevant, even if “both equatorial” is correlated with the other overall transformation, it’s not the causation )
@somebodyelse393 Ай бұрын
@@CasualChemistry oh okok. so its kinetically better to be attacked from the bottom, cause the transition state is more stable this way correct? has nothing to do with hinderance from other groups? (im so sorry to bother you but im so lost visualising this stuff, thank you smm)
@CasualChemistry Ай бұрын
Yes - that’s correct
@ligmabaldrich485 Ай бұрын
Well explained vid! In the first step of the aldehyde synthesis, would it be possible to just use 2 equiv of BuLi to deprotonate the alcohol and then the alkyne, from which the alkynyl anion would react to form the ester first as it is more reactive?
@CasualChemistry Ай бұрын
Thanks 🙂 on paper yes, and sure on a small scale that might work. But there’s a big risk of the the ester forming as well, leading to mixtures as well. And here you couldn’t have excess buli in there either as it could add to the electrophile too. All in all, you’re wanting to maybe do this on 100g ish scale for an early step in a total synthesis so it’s not worth the hassle and the mega dry conditions to use so much BuLi. The cheap and high yielding protecting group is just much easier for handling for sure.
@ligmabaldrich485 Ай бұрын
@CasualChemistry Ahh fair enough. Thanks for the quick reply :)
@joshcantrell8397 2 ай бұрын
How do I know which transition state model to use?
@CasualChemistry 2 ай бұрын
That’s going to totally depend on each individual molecule. So a way to approach is to first identify if your aldehyde is chiral, and then see if each of the assumptions of any model apply. For pure Felkin-Anh, the reaction must be irreversible, and there must be a stereocentre alpha to the aldehyde carbonyl with 3 very distinct groups - this can be on size but electronegative groups can also play the role of “big” groups. If none of these are true, try a different model. If none model available fits, it’s likely the reaction will not be very selective or not selective at all.
@joshcantrell8397 2 ай бұрын
@ thank you.
@joshcantrell8397 2 ай бұрын
Well done!
@CasualChemistry 2 ай бұрын
Thanks 🙂
@BenjaminMenko 2 ай бұрын
what a video
@CasualChemistry 2 ай бұрын
😎 thanks
@_TranGiaBao_A-zy8gh 2 ай бұрын
At 18:35, how would tert-butoxide reduce the risk of elimination on the bromohexane?
@CasualChemistry 2 ай бұрын
Ah - actually I think I have mis-spoken there and haven’t noticed this before. Good spot! Should really say minimise alternative substitution reaction (ie using a non nucleophilic base)
@jeanmbelle7384 2 ай бұрын
your video just help me to solve a problem for my exam preparation. thanks a lot
@CasualChemistry 2 ай бұрын
🙂 You’re welcome - glad it was useful when you needed it
@Transendium 2 ай бұрын
How exactly does the amine on the tBuSONH2 regenerate at the end?
@CasualChemistry 2 ай бұрын
Depends on exactly how you do the work-up - a short video doesn’t give the scope for this. Point is it’s not a catalytic process . But by then end you spit out the main part of the auxiliary molecule, that you can the separate and convert back to the sulfonimide separately (like with any auxiliary), but this is more of a post-reaction admin thing, rather than the key process
@copycat2508 2 ай бұрын
Dear Casual Chemistry, thanks so much for these videos! I keep on finding myself rewatching the same vids of yours to help with my orgo knowledge. We are currently learning this in Professor Jacobsen's class so this is a nice refresher! Hope you are doing well！
@CasualChemistry 2 ай бұрын
😀 Brilliant! Thank you so much for this feedback. It’s exactly what I hoped to achieve by starting this channel that students and beyond will have it there when it’s useful, even if not obvious on a first watch. This type of hopefully evergreen type of video takes a quite a bit of thought on how to pitch the level. I have a few other asymmetric catalysis stuff on my planning board 😎
@thayhuongchuyenhoalekhietq6803 2 ай бұрын
Excellent! Thanks so much!
@CasualChemistry 2 ай бұрын
You’re welcome 🙂
@elmiranadirova2737 2 ай бұрын
One question. Ethylene oxide is gaseous, so is it obtained in situ or purchased in order to conduct a reaction with it?
@CasualChemistry 2 ай бұрын
Never used it myself but it’s boiling point it only about 10 degC so it to be a liquid in the fridge, and you could use it carefully when it’s cold (probably it’s also stored in a high pressure cylinder to help you handle like other things with similar problems). It’s pretty soluble too once you’ve got it into one.
@AB-fk8hl 3 ай бұрын
In the presence of aldehyde and amine, the imine by product is more possible, how its not happening?
@CasualChemistry 3 ай бұрын
Still possible to form the imine, but it can just reverse. The reaction is under thermodynamic control and pushing to the much more favourable product in terms of overall delta G, not restricted by any activation energy barriers.
@alexbeatson1887 3 ай бұрын
your so good man!! Love your explanations. Where in the UK are you working
@CasualChemistry 3 ай бұрын
🙂 Thanks. I teach at a College in Cambridge, some general intro Chem, but mainly organic stuff. Since the pandemic I started using shared whiteboards etc for teaching much more so figured I could put something out there into the wider world too.
@alexbeatson1887 3 ай бұрын
I just want to say you give the clearest explanations I have seen on this topic. Clearly you truly understand what your are teaching!! Sick of seeing others use stupid logic to predict products of asymmetric Aldo’s reactions. You bring everting back to fundamental concepts and I love it!
@CasualChemistry 3 ай бұрын
😎 Thanks. What you say was exactly my motivation for starting the channel in the first place. Making ‘tricks’ and ‘ways of remembering’ for organic chemistry is missing the whole point of the subject in my opinion.
@aurelius388 3 ай бұрын
Transforming the aryl bromide into the corresponding Grignard reagent, with F ortho to it, would have me worried about benzyne formation (around 13:30).
@CasualChemistry 3 ай бұрын
I think it’s safe under normal type conditions. The C-F bond enthalpy is very high and F- isn’t the best leaving group - I’d swap it for a bromide or triflate if I wanted the benzyne.
@mach10maddmikk71 3 ай бұрын
Gerudo valley ♥️
@CasualChemistry 3 ай бұрын
One of my favourites
@unlisted5685 3 ай бұрын
Hey this question might not be related but if 5 hydroxy 2 hexanone is reacted with Hg/Zn (Clemmensen Reduction) what will you get as the product ?
@CasualChemistry 3 ай бұрын
Hmm - to be honest, likely a bit of a mess. Assuming with acid present too, you might hope to get cyclic hemiacetal formation, followed by loss of water then reduction overall to the 2,5-dimethyl-tetrahydrofuran. Mess including, but not limited to, getting the 2,5-diol as well, some some level of separation of products required by the strategy even if you only get these two products. Also risk of elimination of the alcohol in the strong acid to various alkenes. Though it would be would be better to head to the (intended?) 5 membered ring product in a more controlled way, especially if you wanted to do the same mechanism on a more complex molecule. In which case the same mechanism by BF3 as a Lewis acid and Et3SiH as the oxycarbenium ion reducing agent would be much milder, and you might get some level of diastereoselectivity too.
@PoppiD93 3 ай бұрын
Thank you for these retrosynthetic videos. We student often do not have the time to do these exercises. We study a lot of reactions but then don't know how to use this knowledge effectively. It's like knowing all the rules of chess and never playing,
@CasualChemistry 3 ай бұрын
🙂 no worries - glad you find them useful. I am very much aware about exactly as you say about how this subject is taught, usually pretty poorly at universities. I wanted to make my contribution to help out people learning these topics.
@PoppiD93 3 ай бұрын
Excellent video, thank you!
@CasualChemistry 3 ай бұрын
🙂
@DamnBoiya 3 ай бұрын
Hydrogen substitution brother.. I hope I'm right.. please me right haha..
@DamnBoiya 3 ай бұрын
Be
@CasualChemistry 3 ай бұрын
🙂
@DamnBoiya 3 ай бұрын
Just a casual chemist you know how it is
@CasualChemistry 3 ай бұрын
😎
@johannesschneider1784 3 ай бұрын
10:00 Anren't alpha chlorinated ethers among the most hazardous substances? Another reason to use the alternative.
@CasualChemistry 3 ай бұрын
Well, this is true for most good alkylating agents - very not good for the body in lots of ways. But hazardous things can still be handled safely in a lab setting by a trained chemist. Personally, there are worse things that I would have on my avoid list - gases and explosives, for example, and biological agents are much less controllable.
@QWERTY-bc1uq 3 ай бұрын
Weird looking H you got there
@KhushiRohil 3 ай бұрын
Can you please make vedio on retrosynthesis of aceclofenac and diclofenac
@CasualChemistry 3 ай бұрын
I’ll have a think about them but I usually focus on an underlying teaching topic rather than a specific molecule. On a glance it looks like Buchwald-Hartwig couplings would be useful for these.
@safaidres9298 3 ай бұрын
Very helpful thank you so much 🙏🏻
@CasualChemistry 3 ай бұрын
🙂 You’re welcome - glad you enjoyed
@ucewillis 4 ай бұрын
Hello. Cool video cheers. I think is worth pointing out that the methyl and benzyl ether shouldn't be considered 'pretty similar' in size. The benzyl ether is much larger, and while it is more flexible and could adopt conformations to minimise steric hindrance, the methyl group would have a much smaller impact on sterics. Only mentioning this in case people get the wrong idea :)
@CasualChemistry 3 ай бұрын
Thanks 🙂 yes - agreed in hindsight I should’ve at least said locally statically similar or something. I will bear this in mind for future videos
@aurelius388 4 ай бұрын
Great, I've been looking forward to this one. Thank you for all your efforts in making these.
@CasualChemistry 3 ай бұрын
🙂 Thanks. A fiddly one to work out what I wanted to do with this topic.
@EquipteHarry 4 ай бұрын
Perez Mark Clark Anthony Robinson Scott
@Reaboian 4 ай бұрын
OMG Finally You Are Here Agaaaaaaain, hows ur day gooooooing?
@CasualChemistry 4 ай бұрын
🙂 Got more time back to pick up where I left off finally
@aidanlooby 4 ай бұрын
One of my favorite chemistry content creators is back!
@CasualChemistry 4 ай бұрын
🙂 Thanks. Am glad to have the time again to make more content
@hasankoybas1079 4 ай бұрын
Welcome back! Hope your channel grows since very few people teach graduate level organic chemistry on YT
@CasualChemistry 4 ай бұрын
🙂 Thanks. It’s an area I’m hoping I can expand into for sure and hopefully spark some curiosity beyond the usual topics
@triklettriklerbu1592 4 ай бұрын
didnt expect to recieve a notif, nice to see you back bro
@CasualChemistry 4 ай бұрын
🥳 Thanks. Too many work deadlines this year - feels good to be back and play with making these videos
@suneelgaur5246 4 ай бұрын
Great video! I learnt a lot from this.
@CasualChemistry 4 ай бұрын
Thanks 🙂 glad it was helpful
@miroslavstroka281 4 ай бұрын
Is it just me or someone else sees it the same? Should not have the product be the opposite enantiomer? 🤔
@CasualChemistry 4 ай бұрын
I think it’s correct. Note the it’s flipped over from the example in this paper with the aldehyde in the product on the right rather than the left - a rotation not a mirror image. macmillan.princeton.edu/wp-content/uploads/aldehyde-aldol.pdf
@miroslavstroka281 4 ай бұрын
@@CasualChemistry oh, now I see that! Thank you🫶🏻
@Afrin2005 4 ай бұрын
Need ribose
@Gurdeepsingh-wv5tn 4 ай бұрын
Very nice explanation. I have one question, if you are taking R group as a iPr, then enolisation occur from other side because, NEt3 is not that much strong and bulky base.
@CasualChemistry 4 ай бұрын
The main idea is there has to be a difference between the two sides of the carbonyl do differentiate between. The NEt3 is bulky enough but not too bulky to be able to get the H off the ethyl group but not the isopropyl group just on sterics. This is the dominant thing going on. I’m going to touch on this in my next video: another factor is the isopropyl group’s bulk favours the boron Lewis acid sitting on the ethyl group side. There’s also a Stereoelectronic effect that helps make the ethyl group’s protons a bit more acidic. These reactions are done at low temperatures when you need to be careful to select so small differences in activation energies are enough to get selectivity.
@eastofthegreenline3324 4 ай бұрын
The additional info on stereochemistry is helpful. Nice series, thanks!
@CasualChemistry 4 ай бұрын
You’re welcome 🙂
@UniCorneliusfan21 4 ай бұрын
the "magically functionalise an alcohol from an sp3 carbon anywhere" reaction hydrogenation still better imo
@CasualChemistry 4 ай бұрын
It has its place this one, though I’ll admit I’ve only ever done one of these and it was out of desperation. If going via an alkene and hydrogenation, there will be a problem if there’s an alpha stereocentre that you want to keep pure.
@victordonchenko4837 5 ай бұрын
Chemiolis used something similar to make truffle flavor!
@CasualChemistry 4 ай бұрын
Sulfur chemistry gets everywhere (!) 🙂
@jogandsp 5 ай бұрын
When possible, could you please put side products? Maybe like a "-MeOH" or something? It's helpful in thinking through the rxn
@CasualChemistry 5 ай бұрын
Sure - I’ll try and remember in future. It’s not so conventional with this sort of system but I get your point.
@iiscglimpses730 5 ай бұрын
❤❤