7.2 SN1 Reactions | Organic Chemistry
Chad comprehensively covers SN1 reactions beginning with the SN1 reaction mechanism and the SN1 rate law. He shows how the leaving group leaves forming a carbocation in the slow step, and how the substrate is the only reactant in the rate law as SN1 reactions are 1st order. He then explains SN1 reaction stereochemistry, how and why racemization occurs in SN1 reactions when a chiral center is formed, and how the SN1 reaction reactivity order for substrates is from most substituted to least substituted as more substituted carbocations are stable intermediates and form faster in the slow step.
Chad then shows the energy diagram for a typical SN1 reaction and explains how most SN1 reactions involve a weak nucleophile. He then explains how carbocation rearrangements are possible in SN1 reactions, how to predict when they should occur, and the arrow-pushing needed to represent the carbocation rearrangement in the mechanism including for both hydride shifts and alkyl shifts. Finally, Chad concludes the lesson by showing that a polar protic solvent is required in SN1 reactions to stabilize the carbocation intermediate, and that a good leaving group (Cl, Br, I, OTs) is also required.
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00:00 Lesson Introduction
00:53 SN1 Reaction Mechanism and SN1 Rate Law
06:30 SN1 Reaction Stereochemistry - Racemization
09:24 Substrate Effects in SN1 Reactions
11:44 Energy Diagrams for SN1 Reactions
14:45 Nucleophile Effects in SN1 Reactions
16:16 Carbocation Rearrangements in SN1 Reactions
21:38 Polar Protic Solvents in SN1 Reactions
23:37 Good Leaving Groups in SN1 Reactions
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This Thanksgiving I am thankful for Chad and his musical mnemonics.
@ChadsPrep
3 жыл бұрын
Haha! I recognized how bad they really are to the point that I almost didn't include them! 😂👍
@Optometrynerd
9 ай бұрын
I'm so glad you did!@@ChadsPrep
@ChadsPrep
9 ай бұрын
@@Optometrynerd Next time, with harmonica or recorder!
when the wizard is also a bard
@ChadsPrep
3 жыл бұрын
😂😂😂
Chad thank you so much, for having such organized, well-structured videos. These make me feel so confident in organic chemistry and really carry me throughout the units. :) You make hard concepts seem so simple!!
@ChadsPrep
Жыл бұрын
Glad to hear it, Janapriya - Happy Studying!
someone get this man an award!!!!!
@ChadsPrep
2 жыл бұрын
Thank you for your kind words!
I ACTUALLY DO GET OUT MUCH!!! THANK U VERY MUCH, CHAD
@ChadsPrep
Жыл бұрын
You're welcome!
Simply masterful! Thanks Chad
@ChadsPrep
2 жыл бұрын
Glad you enjoyed it!
thank you for making these videos available for everyone
@ChadsPrep
11 ай бұрын
You're welcome
I used to love organic chemistry so much in high school, but my (real-life) organic chef professor is doing a terrible job. I've been studying organic chemistry with you for almost a month now, and you are making me ENJOY the beauty of organic chemistry all over again. Even sometimes my subconscious thinks that you're my real professor because I follow with you more than I do with the "real one" XD. Thanks a lot prof. Chad!
@ChadsPrep
2 жыл бұрын
Very kind words - thank you, Ahmad Saeed.
Chad, a year ago you saved me from failing my General Chemistry course, and this year I hope the same will happen with Organic Chemistry! You are the best in terms of science explanation. Thanks for what you are doing!
@ChadsPrep
7 ай бұрын
Glad the channel is helping you out so much - all the best in your studies!
Chad, you are a real God send. thank you
@ChadsPrep
11 ай бұрын
You're welcome and Thank You.
Thank you for the great content! I have my exam tomorrow and your videos have been really helpful! If I get an A its because of you. 😆😊
@ChadsPrep
2 жыл бұрын
Glad the channel could help you achieve your goals - hope you did well and continue doing so!
You are amazing teacher! Thank you so much for making this it helps me a lot!
@ChadsPrep
Жыл бұрын
You're welcome and Thank You!
I was recommended your videos by another student and man, I'm impressed! These reactions gave me so much trouble since I missed out on the lectures and my professor is a bit all over the place so her explanations are a bit wonky (she's amazing but a bit inexperienced unfortunately). I'm finally understand what's actually going on! And I do have a final soon and I'm actually confident I'm gonna pass! Thank you for doing these!
@ChadsPrep
Жыл бұрын
You're welcome and I hope you do well on your final!
Excellent video. Congrats.
@ChadsPrep
8 ай бұрын
Thank you
Thank you! you are amazing!
@ChadsPrep
Жыл бұрын
You're welcome and Thank You.
Thank you so much 😻❤️you really are a life saver
@ChadsPrep
10 ай бұрын
You're welcome and Thank You.
Sn2 backside attack, sn1 carbocation! 🤩I will always remember them.🤩
@ChadsPrep
10 ай бұрын
👍👍👍
I love the song it's a hit
@ChadsPrep
3 жыл бұрын
Excellent! I think we can safely say that I should give up teaching and pursue a career where my real talent lies!😜
Super sir excellent explanation, iam from India ❤
@ChadsPrep
6 ай бұрын
Thanks and welcome from the USA!
05:55 Wouldn't it be better for the bromide ion to deprotonate that oxonium? It is negatively charged, while the solvent (methanol) has no charge. Taking the proton would give it a positive charge, which I don't think it's willing to have. I mean, sure, the solvent may intermediate in carrying that proton from one molecule to another, but eventually, shouldn't it end up on the negatively-charged bromide and stick there to neutralize all the charges?
At 20:05 does the product have an internal plane of symmetry therefore its achiral? Or just bc its the same around the ring
I thought more substituted carbocations would be more stable and therefore lower in energy (also more substituted is favored). Why is it at 15:27 you mention that the carbocation is higher in energy and less stable?
in 19:52 , isn't the product of proton transfer produce CH2? Not CH3?
i'm literally only passing thanks to you lol thanks
@ChadsPrep
3 ай бұрын
Very welcome!
omg your song is stuck on my mind loll
@ChadsPrep
3 жыл бұрын
Making a difference in as many lives as I can, Julia! 😛🤣
why in the major product do we add a OCH3 instead of just OH?
@awesomeperson3161
2 жыл бұрын
hello, i am by no means a professional...just another student taking the class. But I think this is because it is being deprotonated (losing a proton/hydrogen) to the Ch3OH (also works a solvent) and so if you remove a hydrogen from CH3OH it just becomes OCH3 (with a neg charge). OH is not as a result of this. I think the instance you are think of when it becomes OH is when it is in a strong base (but here we are looking at it as a nucleophile).
Best song ever
@ChadsPrep
9 ай бұрын
You're for FREEEE!
21:09 For this part do we need to show the substituents as a wedge or dash? Or is it okay to write them in a flat position?
@ChadsPrep
Жыл бұрын
Hey - around 20:15 I explain that since this is not a chiral center we don't have to show the wedge/dash
why fluoride is a good nucleophile in polar aprotic solvent? as we know the negative charge is stable on highly electronegativeatom.shouldnot iodine be good nucleophile due to high polarazibity.
@betul1860
8 ай бұрын
Aprotic solvents are not capable of forming hydrogen bonds. In a polar aprotic solvent, F can not be surrounded by solvent molecules thus it can attack the leaving group. Since F is more electronegative than Iodine, it would be a better nucleophile.
i wish i had u as a professor
@ChadsPrep
9 ай бұрын
Thank you
Why does the nitrate ion of the AgNO3 not perform as a nucleophil?
@ChadsPrep
9 ай бұрын
Hey Nils, Nitrate is actually a very weak nucleophile due to stabilization by induction to electronegative atoms and considerable resonce. Remember stable negative ions are poor nucelophiles because they are happier on their own and don't readily attack anything via substitution
that vacation joke really feels hurt
@ChadsPrep
3 жыл бұрын
😜😎
I will never forget the song🫡
@ChadsPrep
5 ай бұрын
Mission accomplished!