I think that rxn requires very strong acid like Sulfuric acid which can break the aromaticity. Maybe hydrogen is added on the para position from hydroxy group. At that time, carbocation of meta position is pretty stabilized because its resonance form makes carbonyl compound which is stable than carbocation.(due to octet rule) And then HSO4- eliminates a hydrogen from t-butyl group to afford products.(driving force : recovery of aromaticity)
this reaction is routinely performed by undergraduate students, but the product they isolate is dibenzylideneacetone. maybe you'd be able to get this product with excess acetone present
Wow, that next week reaction looks crazy! Seems like a kind of retro-Friedel Crafts alkylation. My guess is, acid protonates the aromatic carbon holding the tertbutyl (which has more electrinuc density due to OH donating group), then the aromatic ring is restored by kicking out the tertbutyl gropu as a tertiary carbocation, which then forms isobutene in an E1 reaction, libersting a proton
This is a really excellent question. I have a long answer that will likely be unsatisfactory to many organic chemists. To start, I'm an INORGANIC chemist by training, and that means that the way I think about chemical reactivity is a bit different than trained organic chemists. I like to think about elimination reactions as a spectrum. On one end of the spectrum are E1 mechanisms being unimolecular, E2 mechanisms being somewhere in the middle of the spectrum as I've shown in the video, and then E1cb mechanisms being on the opposite end of the spectrum. You're absolutely right that aldol condensation reactions are typically taught as E1cb mechanisms, but for me, I've never really understood the point. To me, the transformation and the pathway are the same, the existence of the intermediate enolate/carbanion is really the differentiating factor. As an inorganic chemist, this subtle difference is irrelevant to me, especially since I don't think the enolate formation would be reversible and I don't think the final step in the E1cb mechanism would be the rate-determining step. I also think E1cb mechanisms require very basic conditions and while NaOH is obviously a strong base, since the reaction is in EtOH, that base will only be sparingly soluble limiting the basicity of the solution. Therefore, I think it's an interesting discussion to have that, to me, isn't really important in the long run. Because you get the same thing no matter what. I'm sure these statements are offending the world of organic chemists, but I'm used to that as an inorganic chemist. To be fair, I'd also be willing to fight anyone who suggests something like the Jahn-Teller effect is real, thus offending a host of inorganic chemists as well.
@@rojaslab Can you make a video on Jahn Teller effects and why you disagree with it? I have watch some of your inorganic chemistry videos but haven't see a discusstion on this topic (maybe I should check again to make sure)
@@_TranGiaBao_A-zy8gh You're right that I haven't. I talk about it in my real live courses but it's a great idea to make a video about it. Honestly, I've probably just been trying to avoid to drama and arguments that will ensue haha
Great video as always, but the product is not cinnamaldehyde, it is not even an aldehyde
lmao. Now you've got me wondering what the heck was I thinking?!
Hi
yay, i this was the first mechanism i was able to come up with pretty much on my own!
Boom! That's awesome news. Excited to see you get next week's mechanism too!
@@rojaslab I'll try!
I think that rxn requires very strong acid like Sulfuric acid which can break the aromaticity.
Maybe hydrogen is added on the para position from hydroxy group. At that time, carbocation of meta position is pretty stabilized because its resonance form makes carbonyl compound which is stable than carbocation.(due to octet rule)
And then HSO4- eliminates a hydrogen from t-butyl group to afford products.(driving force : recovery of aromaticity)
You’ve got a keen eye for the nuance of that protonation step!
this reaction is routinely performed by undergraduate students, but the product they isolate is dibenzylideneacetone. maybe you'd be able to get this product with excess acetone present
I think it would depend on the stoichiometry and order in which the reagents were added. But that’s a great idea for a future mechanism problem!
Wow, that next week reaction looks crazy! Seems like a kind of retro-Friedel Crafts alkylation. My guess is, acid protonates the aromatic carbon holding the tertbutyl (which has more electrinuc density due to OH donating group), then the aromatic ring is restored by kicking out the tertbutyl gropu as a tertiary carbocation, which then forms isobutene in an E1 reaction, libersting a proton
You are absolutely crushing it!
Why do you suggest the E2 mechanism for the formation of the double bond instead of E1cb, which is typical of aldol condensation?
This is a really excellent question. I have a long answer that will likely be unsatisfactory to many organic chemists. To start, I'm an INORGANIC chemist by training, and that means that the way I think about chemical reactivity is a bit different than trained organic chemists. I like to think about elimination reactions as a spectrum. On one end of the spectrum are E1 mechanisms being unimolecular, E2 mechanisms being somewhere in the middle of the spectrum as I've shown in the video, and then E1cb mechanisms being on the opposite end of the spectrum. You're absolutely right that aldol condensation reactions are typically taught as E1cb mechanisms, but for me, I've never really understood the point. To me, the transformation and the pathway are the same, the existence of the intermediate enolate/carbanion is really the differentiating factor. As an inorganic chemist, this subtle difference is irrelevant to me, especially since I don't think the enolate formation would be reversible and I don't think the final step in the E1cb mechanism would be the rate-determining step. I also think E1cb mechanisms require very basic conditions and while NaOH is obviously a strong base, since the reaction is in EtOH, that base will only be sparingly soluble limiting the basicity of the solution. Therefore, I think it's an interesting discussion to have that, to me, isn't really important in the long run. Because you get the same thing no matter what. I'm sure these statements are offending the world of organic chemists, but I'm used to that as an inorganic chemist. To be fair, I'd also be willing to fight anyone who suggests something like the Jahn-Teller effect is real, thus offending a host of inorganic chemists as well.
@@rojaslab Can you make a video on Jahn Teller effects and why you disagree with it? I have watch some of your inorganic chemistry videos but haven't see a discusstion on this topic (maybe I should check again to make sure)
@@_TranGiaBao_A-zy8gh You're right that I haven't. I talk about it in my real live courses but it's a great idea to make a video about it. Honestly, I've probably just been trying to avoid to drama and arguments that will ensue haha
That next one looks similar to the cumene process.
The cumene process is pretty cool! This proceed through a more familiar and fundamental mechanism though!
So you want me to dissolve NaOH in EtOH😮💨
Haha. I didn’t say any of this would be fun!
Funny lol enolate chemistry I thinky
You got it! But do you remember what the reaction is called?
@@rojaslabis it a Michael addition ? Or aldol the product is a 1,3 relationship so I think aldol since Michael is 1,4 I think