Nucleophilic Substitution Reactions - SN1 and SN2 Mechanism, Organic Chemistry

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  • Опубликовано: 27 дек 2024

Комментарии • 277

  • @TheOrganicChemistryTutor
    @TheOrganicChemistryTutor  2 года назад +59

    Organic Chemistry PDF Worksheets: www.video-tutor.net/orgo-chem.html
    Full-Length Exams and Worksheets: www.patreon.com/MathScienceTutor/collections
    SN1 SN2 E1 E2 Reactions Test Review: bit.ly/3Bt4ghw
    Organic Chemistry Final Exam Review: bit.ly/2WCJ8GP

  • @liviachung7607
    @liviachung7607 2 года назад +307

    "let's not worry about stereochemistry in this example"
    I think that is the sexiest thing a chemistry teacher could ever say

  • @nizzlenotes3892
    @nizzlenotes3892 4 года назад +2275

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      @gigachad5029 4 года назад +45

      Its friking hard

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      @akashsunil7464 4 года назад +34

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      @dhruvavikas1632 3 года назад +23

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    @simrinsahota2398 Год назад +50

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  • @drewruble8027
    @drewruble8027 5 лет назад +332

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  • @sqectre
    @sqectre 6 лет назад +703

    @1:46 you say "the SN1 reaction occurs in a single step" For anyone else thatt might be reading this, it's supposed to say "the SN2 reaction" not "SN1"

    • @TheMOZADI
      @TheMOZADI 5 лет назад

      yes

    • @nkag545
      @nkag545 5 лет назад

      Yes

    • @PhoenixBlade538
      @PhoenixBlade538 4 года назад +10

      I was wondering about that. Thank you!

    • @pfeliciano4062
      @pfeliciano4062 3 года назад +1

      Yes, I just caught that as well!

    • @serenitylanclos2686
      @serenitylanclos2686 3 года назад +12

      I wish I would've read this comment 30 mins ago!!! I had to pop out my textbook cause I was so confused!!!! Thank you! two years later lol

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    @jasleendhillon8883 8 месяцев назад +55

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    @realdeal8452 3 года назад +343

    You teach better in 15 minutes then my "professors" who leave me so confused after 2 hours.

    • @kevinhan2581
      @kevinhan2581 2 года назад +8

      Sure. Same for me. Professor said: you will learn it later on lessons. For me, It feels like pre-view and "waste" of time.

    • @conchadeconchos
      @conchadeconchos Год назад +1

      @@kevinhan2581dude the amount of times my proff said “keep this in mind it doesn’t make sense now, but it’ll make sense later”
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    @jcarter7456 6 лет назад +542

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      lmfaooooo

  • @KushagraThakur.
    @KushagraThakur. 2 дня назад

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    @pilgrimsbrother3135 3 года назад +8

    My Doctorate lecturer, I just take this opportunity to express my sincere gratitude for enabling me to pass my exams and cats. Actually, you are a hero to be remembered. I revised all the problems and guess what. Exam was just a celebration!!. Long live my master.

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    @calebkimmel372 Год назад +12

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  • @edwinafrimpong1392
    @edwinafrimpong1392 5 лет назад +38

    You guys have no idea how I've been battling to get the Sn1 and Sn2 reactions. Thanks

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    @karimmiller-green6676 4 года назад +31

    Biology is my subject, i was never really good at chem, but watching your videos clarifies alot.

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    @hunterlongbrake6268 3 года назад +4

    This channel is doing the Lord's work. Thank you.

  • @sahilagarwal7752
    @sahilagarwal7752 5 лет назад +121

    I have to criticize a bit. Sn2 has 2 in its name not because it is second order overall but because it is a bimolecular nucleophilic substitution, emphasis on bi. Sn2 can occur as a pseudo-first order reaction in case of solvolysis(when the solvent is the nucleophile and is in excess)! But otherwise, thank you for this video.

    • @okayhaffy
      @okayhaffy 2 года назад +13

      bimolecular literally means it is a second order reaction

    • @pabloooooooooooo6621
      @pabloooooooooooo6621 2 месяца назад

      @@okayhaffy no rate = k [a]^2 you would say this is still second order ,I thought. (I could be wrong)

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    @cynr6406 5 лет назад +176

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    @baptizedInFire27 4 года назад +4

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    @basmamohammed888 6 лет назад +12

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    @vimch7264 2 года назад +11

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    @rochanhm 6 лет назад +13

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    @mingminglolrock 5 лет назад +9

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    @翁尧 5 лет назад +3

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    @lizdyel172 Год назад

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    @adamusmani 3 года назад +3

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    @aracelihernandez802 2 года назад +2

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  • @tfee1243
    @tfee1243 6 лет назад +125

    Good work, but it was very confusing when you switch from sn1 to Sn2 without saying anything so i cant tell which is which

    • @betelgueseromanicontidesu6671
      @betelgueseromanicontidesu6671 5 лет назад +29

      First look at the Alpha C. Is is a primary, secondary, or tertiary C? If it is Primary, it will always be Sn2 (minus a couple instances), if it is secondary you need to look at what you are reacting with and the protic/aprotic conditions along with the leaving group, if it is tertiary is always favors Sn1.

    • @yasssgawwwd5643
      @yasssgawwwd5643 4 года назад +8

      It’s implied when we discuss sn1/sn2. The biggest thing to remember (what I learned) is that sn1 is usually a 2 step process while sn2 are 1 step:) hope it helps. There’s basic rules to help you immediately see the rxn that will happen when u see the reagent with starting material. So primary, sec, and tertiary substrates helps me know whether the rxn will proceed in either sn1 or sn2. Check the Carbon:)

    • @kuewayneennis9521
      @kuewayneennis9521 4 года назад +4

      @@yasssgawwwd5643 bruh that message Is2 years ago, and he just made some mistakes in the video tbh said sn1 when he meant sn2

    • @k-l-a-r-a
      @k-l-a-r-a Год назад +2

      ​@kuewayneennis9521 Yes! I was also confused because at 1:47 he says "The SN1 reaction." while he meant SN2! I hope there aren't more confusions?
      Also how ironic rn, your comment is 2 yo for me 😂😂

  • @dvrsify1
    @dvrsify1 Год назад

    I love this channel so much

  • @ahmadjarrad2635
    @ahmadjarrad2635 3 года назад +2

    Why does the intermediate molecule at 14:21 let go of the hydrogen instead of the methyl group? What makes it more favorable? Why would the methanol want the hydrogen? Wouldn't it have to dissociate for the OH- to grab the H+ and become H2O, leaving a methyl ion CH3+, which is kinda unfavorable?

  • @kei6400
    @kei6400 5 лет назад +6

    In your first example, isn't iodine a better leaving group, and thus a weaker base, than bromine? So the reaction will not proceed, or will at least favor the reactants if the reactions is reversible

  • @Konstinho
    @Konstinho 4 года назад +2

    I hope you know how important your videos to us are. Thanks

  • @sajkdnsaklfhnj
    @sajkdnsaklfhnj 2 года назад +1

    I love your videos, they're informative and kinda asmr lol thank you so much.

  • @lizardperson2293
    @lizardperson2293 7 лет назад +70

    1:46 don't you mean Sn2?

    • @Oasix21
      @Oasix21 7 лет назад +11

      Yes SN2 is Concerted single step, while SN1 is multi step.

    • @BeautyByIris08
      @BeautyByIris08 6 лет назад

      That's what I was thinking too

    • @papaisduniyakapapa
      @papaisduniyakapapa 4 года назад

      Does Carbonation formation occur in SN1?

  • @lianasong9926
    @lianasong9926 3 года назад +3

    hi not sure if you can see this comment since this is a pretty old video,, but im open to anyone who can answer my question: for 17:43 product, is it not going to be a racemic mixture just like the previous example since H2O is a neutral nucleophile?

  • @PublicHealthForYou
    @PublicHealthForYou 2 года назад

    Its me from Nepal
    Your videos are extraordinary sir 🥰

  • @anshulramprasad5869
    @anshulramprasad5869 6 лет назад +7

    Hello! This was awesome, thanks alot for your tutoring!! It helps alot😁

  • @JamessProductionss
    @JamessProductionss 7 лет назад +9

    thanks for your videos dude, very helpful!

  • @bonbonpony
    @bonbonpony 3 года назад +2

    01:41 Dear Princess Celestia, today I learned that Iodide is a naughty backstabber :J (it's also a good nucleophile, they say)
    06:02 What do you mean "leaves"? It can't just break that bond, withdraw its electrons and leave all by itself, can it? It it's better off alone, why would it form a bond with that carbon to begin with? :q
    08:18 Is there any way to separate those two products from the mixture?

  • @jessicajane2400
    @jessicajane2400 2 года назад

    @7:48- how do we know if the Nu: attacks from the front or back?? I know that you said it should attack from the back and why, but is that always the case? Can you explain this further? Should it always attack from the back WBR the Nu: is a Br-?

  • @Jake0405
    @Jake0405 2 месяца назад

    magnificent, all 360p's of it

  • @ua4788
    @ua4788 4 года назад +1

    you are the best!!!!!

  • @kalei7599
    @kalei7599 4 года назад +2

    correct me if I'm wrong, but I'm pretty sure that the second example can only work with E2. SN1 does not work under strong basic conditions.

  • @tristan6773
    @tristan6773 7 лет назад +3

    Substitution reactions prefer formation of the more stable base. Reacting iodine with an alkyl-bromide would produce no reaction. Please clarify this

  • @Ghost-pr4fq
    @Ghost-pr4fq 5 лет назад +1

    at 4:05 you were drawing 2-bromo-2-methylpropane but as you can see that you made mistake for that methyl (to the left of this molecule.) C and H suppose to be switched or else I will think that the carbon in the center of the molecule is connected to the hydrogen and that hydrogen is connected to the other carbon which that is crazy.

  • @tg9521
    @tg9521 11 месяцев назад

    I need to know this for a test in less than 1.5 hour. Thanks.

  • @zubaidakhan4132
    @zubaidakhan4132 4 года назад

    Very good effort👍

  • @joshjaba4464
    @joshjaba4464 4 года назад

    this video helped me out a lot

  • @S_R_B-b9l
    @S_R_B-b9l 3 года назад

    My guy, you are a B L E S S I N G

  • @saracurato
    @saracurato 4 месяца назад

    Thank u so much for this video

  • @samli3294
    @samli3294 Год назад +1

    does SN2 and SN1 work for alkane, alkene and alkynes or only for alkyl halides?

  • @jacobchristensen6235
    @jacobchristensen6235 4 года назад

    Why will methanol remove the hydrogen and not the methyl Group on the oxygen? At 14:18
    Is there any law on why it pick that?

    • @bonbonpony
      @bonbonpony 3 года назад

      The simplest answer is: we've just done a nucleophile-electrophile reaction when that oxygen attacked the carbocation, so the next step shouldn't be another nucleophile-electrophile reaction, but an acid-base reaction instead. And acid-base reactions are all about giving/taking protons (hydrogen nuclei).
      Also hydrogens are relatively easy to detach, because they're very small when compared with any other atom. They can just lose one electron to the oxygen and leave when someone else offers them another electron. Bonds between carbon and oxygen are harder to break, because carbon is not very happy either when losing or gaining an electron.

  • @NA-so1ke
    @NA-so1ke 4 года назад +2

    Is this for the AS level?

  • @nkag545
    @nkag545 5 лет назад +2

    Thank you so much sir !

  • @kobyplays8840
    @kobyplays8840 2 года назад +1

    Not me checking how to do this 5 minutes before the exam 🎉

  • @adelapizha6885
    @adelapizha6885 3 года назад

    the fact that i can understand him and not my professor!!!!

  • @beastypie99
    @beastypie99 4 года назад +1

    For the last molecule, would it actually have 4 steroisomers? The methyl-substituted carbon is an asymmetric center, and I assume the methyl shift could add to either side.

  • @amoshunja5924
    @amoshunja5924 8 месяцев назад

    Very helpful

  • @BryanChege
    @BryanChege 8 месяцев назад

    so helpful!

  • @Rajeevnair1959r
    @Rajeevnair1959r 5 лет назад

    At 17:23, Why isnt the other carbon chiral? Also aren't the two carbons 4° and 3° respectively? Someone help!

    • @Julian-pq4lw
      @Julian-pq4lw 5 лет назад

      Well the 3° carbon is chiral and no because only carbon-carbon bonds count, so the 2° carbon is bonded with 2 other carbons thats why its 2° and the 3° is bonded with 3 carbons and so its 3°

  • @alondraherrera4170
    @alondraherrera4170 3 года назад +1

    how do you know if it attacks from behind or in front

  • @sarahmarcel9806
    @sarahmarcel9806 Год назад

    THANKYOU LIFESAVER!!!!

  • @yousafilyas3987
    @yousafilyas3987 2 года назад

    What is the link to video that has 75 practice problems?

  • @flannel7977
    @flannel7977 2 месяца назад

    on the last problem, how do you which is r and s? there's no methyl on a dashed or wedge bond.

  • @gabsantos601
    @gabsantos601 Год назад +1

    Did you mean to say Sn2 at 1:46?

  • @VoiceBox24
    @VoiceBox24 5 лет назад +1

    have my natural products test on Friday haha

  • @Dwanye01
    @Dwanye01 2 года назад +1

    at 1:46 you say "the SN1 reaction is a concerted reaction" when it should be SN2!

  • @NoOne-yv2ei
    @NoOne-yv2ei 2 года назад +1

    There are a few strange things:
    1. I is a better LG than Br so it shouldn’t react
    2. Methanol is acidic and would not accept protons

  • @jasontodd6850
    @jasontodd6850 5 лет назад +3

    i tought I- was a better abandonat group than Br- . but in the video you use Br- as the abandonat group. i am kinda cofused. can somebody explain?

  • @bobu5213
    @bobu5213 4 года назад

    14:10 wait why does this intermediate form? Oxygen seems to have 8 electrons so why does it bare a positive charge?

    • @rileymurtagh3365
      @rileymurtagh3365 4 года назад +1

      Formal charge of the electron is +1
      formal charge = valence electrons of the free atom - non bonding electrons - 1/2 of the bonding electrons
      oxygen has 6 valence electrons and here 2 are not bonded, and it has 3 bonds (each bond consists of 2 electrons)
      6 minus 2 minus 3
      +1 on the oxygen
      :)

  • @ro1882
    @ro1882 4 года назад

    do your videos have any order and organization? I don't want to jump from one video to the next.

  • @DeniseP
    @DeniseP 2 года назад +1

    1:46 is Sn2 (not Sn1)

  • @remi4712
    @remi4712 5 лет назад +11

    My exam on this is today 😂😂

  • @kengchiaming6471
    @kengchiaming6471 Год назад

    Any practice question for reaction with formic acid?

  • @moyinoluwaesther438
    @moyinoluwaesther438 Год назад

    So, what type of nucleophile will determine if it will be a SN1 reaction or a SN2 reaction?

  • @SI-23574
    @SI-23574 3 года назад

    Why does the oxygen develop a partial positive charge instead of negative when bonding to the carbocation?

  • @Praetor96
    @Praetor96 6 лет назад +4

    Guys, there is never a backside attack on an Sn1 reaction... Don't know what he was talking about there around 1:46

    • @StfuSiriusly
      @StfuSiriusly 6 лет назад +3

      He said it is SN2 not SN1

    • @nGUNNARp
      @nGUNNARp 6 лет назад +1

      @@StfuSiriusly nah he said sn1, he just misspoke there, he is talking about sn2

    • @xantherxavier5429
      @xantherxavier5429 6 лет назад +1

      Now, I could be wrong here, but maybe, just maybe, he meant to say SN2....Ever consider that, genius?
      Also, backside attacks can occur in SN1 reactions...Take a look at his example at 7:37

    • @jakedassan4117
      @jakedassan4117 6 лет назад +2

      @@xantherxavier5429 obviously, doesn't mean it's not gonna confuse the crap out of some students
      Ever consider that genius?

    • @Home-u6g
      @Home-u6g 5 лет назад +2

      @@xantherxavier5429 Why such a dick? A glaring mistake like that is the video makers fault, people are allowed to call him out on it

  • @dharanidhara1997
    @dharanidhara1997 3 года назад

    U said that "since bromide repels oxygen ....inverted product will be formed"....but this is Sn1 reaction so the leaving group have already expelled ...then there will be no repulsion for oxygen right ??? Kindly answer

  • @khurramjaved2580
    @khurramjaved2580 10 месяцев назад

    Hello
    How do you know what's front and what's back? Isn't that relative?
    Thanks

  • @FatimaKhazaal534
    @FatimaKhazaal534 3 года назад

    Thank you so much

  • @osasumwenoribo140
    @osasumwenoribo140 3 года назад

    What else could replace this method ? -In case it is needed.

  • @happypenguin64
    @happypenguin64 5 лет назад

    What type of stereoisomers are the molecules in the last example?

  • @marycu9066
    @marycu9066 6 лет назад +2

    Overall, this video is very helpful. However, I'd like to point out that at many points in the video, some terms are not very clearly pronounced.

  • @zanapavlovic2611
    @zanapavlovic2611 5 лет назад +1

    I don't get how the bromide affects the water if it attacks from the front of the molecule, but not the back? It's all in the same solution, right? So, why can't the bromide affect the water if it's attacking from the back?

    • @bonbonpony
      @bonbonpony 3 года назад +1

      It's not really about "front" and "back", but about "one side of the plane" and "another side of the plane". That carbocation is sp²-hybridized, so its geometry is trigonal planar, and normally the water molecule could attack it from both sides. But the negative bromide ion is still hanging around nearby, attracted by that positive carbocation, and partially blocking the way from one side for that water molecule. Therefore, that water molecule has still a better chance of attacking the carbocation from one side (the one without the bromide ion) than the other (where the bromide is still hanging around and blocking its way).

  • @Jayypee2
    @Jayypee2 6 лет назад

    Can you please reply asap. Is 1:46 right or not because I dont understand

    • @killer-yv1zp
      @killer-yv1zp 6 лет назад +1

      he made a mistake. SN2 reactions are always one step while SN1 are multi-step reactions. Hope it clears it up for you

  • @mekdelawitalemu1401
    @mekdelawitalemu1401 2 года назад

    Is there any influence in percent of racemic mixtures if the bromine is put in front or at the back of carbon atom?

    • @NoOne-yv2ei
      @NoOne-yv2ei 2 года назад

      No because all reasoning is reversed

  • @sara-ie8ri
    @sara-ie8ri 4 года назад +1

    hmm why these guys are explaining things to us on youtube?!! this should be my professor

  • @1515Wong
    @1515Wong 7 лет назад +4

    thanks!!!

  • @hamzaabbaszaidi8788
    @hamzaabbaszaidi8788 4 года назад

    Can someone explain what he does at 2:18?

    • @rileymurtagh3365
      @rileymurtagh3365 4 года назад

      He determines the rotation of the molecule, assigning power to the atoms of greatest atomic mass attached to the stereogenic center, Hydrogen is always 4 if present on a stereogenic center as it i's AMU is 1, Bromine is heavier than the other molecules so it is assigned as 1, then the Ethyl is 2 and the Methyl is 3.
      You don't do this if any of the substituents are the same, Ethyl and Methyl while both being carbon attached to the sterogenic center can be exempt as you just assign power to the next atom it is connected to for example
      Methyl vs Ethyl
      carbon vs carbon = no winner
      so we determine power with the next atoms
      hydrogen vs carbon = carbon wins as there is a second carbon in the ethyl group and thus assigned higher power.
      Feel free to correct me, but this is my understanding.

  • @hendanbm6572
    @hendanbm6572 Год назад

    Isn’t iodide weaker than bromide making it unable to remove it?

  • @eliasgermer8762
    @eliasgermer8762 2 года назад

    Thank you! But why does the carbocation forms? I mean, how come the carbon-bromide bond just splits?

    • @isaach8289
      @isaach8289 2 года назад

      you dont really need to know those but it is because of the dipole interaction between carbon and bromine.