Skip to main content
Loading Explore guides…
SN1 vs SN2 vs E1 vs E2 Reactions · Acedra
Home
Explore
Chemistry
SN1 vs SN2 vs E1 vs E2 Reactions
Sign in to save
Chat
If YouTube asks you to sign in, open the video on YouTube.
Watch on YouTube
Reload player
Transcript
18 segments
Copy
Hide video
0:00
so we're going to keep it pretty simple where difficulty level one all we're focusing on is labeling each reaction as sn1 or sn2 mhm if we were looking at this one what do you think it would be how can we tell from this let's say this is sn2 why um well I'm looking at the nucleophile it's a strong nucleophile perfect I'm going to stop you right there you did that perfectly so you said okay I'm going to label this and I'm going to see that this is strong mhm so okay I have a strong
0:33
nucleophile and then from there another thing that we could look at is looking at the alal haly that we started off with what kind is it how would we classify that as secondary good so that's another thing I can look at it and see well I know that this is secondary those are two things that are going to tell me what type of reaction it is and you're completely right I know that when I do have something that has a strong nucleophile and it can work with it secondary alal halide that is going
1:02
to be sn2 mhm versus sn1 we would have really spotted it from the nucleophile this isn't weak it's strong so yep sn2 perfect op to a good start good good let's keep going go for it what do we think okay so I'm looking at it it's got a charge so I know it's a strong nucleophile good um and then I look at this and this alkal halide is primary so I know it have to [Music] be once again sn2 yep no trick here I know that this is sn2 because Yep this is primary I know
1:40
this is a strong nucleophile that checks out that's it yay what about this one okay so I have an alcohol which is neutral okay um and then on this guy right here it is secondary well really I guess the indicator would be the nucleophile because it's neutral it have to be sn1 this is a secondary which works for both sn1 and sn2 it does how else can we classify that alal halight as um alyc good so it is secondary and it's also alyc which makes it even faster when it
2:15
is ayc that's true so okay you're right it's s in one because this is neutral this still works with something that's secondary and especially works with something that's ayc yeah okay all right now let's look at this one this is a solvent right DMS okay it is which will be an sn2 solvent I guess that's kind of the biggest thing I'm looking at but I guess I can look at this up here which would have a charge good which would make it strong perfect that's strong I'm
2:42
going to go back to the solvent what type is it is it pric AIC it is AIC good we also knew that because it does work with an s& reaction because we saw that this was strong mhm so yep that's good AIC could have also seen that with going back back to our examples it's DMF yep I have DMF that works with sn2 reactions versus our pric solvents are something like water alcohol and amine carboxylic acid those are the common ones mhm but good yay and then also we could have
3:15
looked at the alal halide how would you classify that as that one would be secondary perfect so label it beautiful I'm also going to mention one thing we could have noticed because we are given the product there's version there's only one product here mhm because this is sn2 right that backside attack now we're going to see in a second something else okay with stereochemistry isn't it called racemization yes okay remember renion and version right yes good okay
3:48
good good so I'll bring this one it's exactly what you're saying mhm where we have two products now yes what do we think this is this one will be SN one good keep saying telling me why um so so there's an alcohol which again neutral which will be better in an aoic so like you know sn1 reaction I guess pric um pric yes sorry and then right here we have you know chyo Center but we have two like different bonds like we have a wedge and then we have dash at switch giving us two
4:20
reactions good what did we say that that was with stereochemistry uh rization good so and that was when we have retention just meaning that our first product will keep the same Bond so really the same configuration RS and then inversion completely change it and that's where we see here another thing is the fact that how would we label this alkal haly oh like what we categorizes yes classify it would be a tertiary good okay and that only works with SN one that's another one that we could have
4:52
seen okay that had to have been SN one SN two that doesn't work okay that's true that's true there's a lot of reasons that we can kind of pin Point what it is okay that's good a lot of support we're going to move on to this next question so it's still difficulty level one this time we're going to label each reaction as E1 or E2 okay so let's do the same thing what are you thinking um in this one I want to say it's E2 why cuz once again strong base MH um and then they both have like terish or
5:21
secondary that like would work for either but I think that's like the biggest one that I can think of that is and then yes you're right the fact that this is secondary mhm go ahead and label what you think it is E2 the main reason yep is because that is a strong base that's really it I know that for E2 and E1 it's really the same sort of substrates that we're going to have main difference is going to be the strong base and weak base plus we could have noticed the type of solvent that we had
5:48
that would have been AIC that's true but off to a good start what about this one NH3 with heat it'd be E1 why or is that a guess I feel like I F confid on it okay but I just this right here is kind of throwing me off but I guess I'm we're looking at this I don't know actually is it not E1 so looking at this it's not going to necessarily save you right because E1 E2 both have tertiary preer prefer tertiary right and secondary this is classified as what that one would be
6:19
um secondary oh actually no tertiary because the wedge good so I'll classify that does that part really matter no not like to it's not going to help you it's not going to save you at least with E1 and E2 yeah with all of them yes that's helpful the main thing again is looking at the base does this have a charge that one no no okay that's that's one thing next does this have any like na lithium potassium that's our our spectator ions right and then that would tell us there
6:51
is a charge yeah so the fact that that doesn't have anything this is going to be weak okay that's why so it would be E1 cuz it's weak yes and this goes way back to Jen Kem where this was a week base that's right a while ago I know but it comes a little bit it sneaks in there yeah but this would have been a weak base okay that's right that's right something else that you haven't necessarily seen with your textbook but maybe the ACs will throw it is heat whenever we do see heat we're going to
7:21
have some sort of elimination reaction it's preferred the main reason why heat is involved here is just to speed up the reaction oh okay yeah but just kind of throwing something new at you here cuz I know you're not familiar with this one but that's kind of like the checklist that you go down like okay I don't really know what this is I didn't memorize that that was the type right or I'm not familiar with it but does this have a charge no does it have a spectator ion like sodium lithium or
7:47
pottassium no okay it's weak okay that makes sense and he you said elimination both e went a yes that would have been an educated guess if you would to do that on an exam let's do this one o okay we got bulky base good it's E2 right good that's right what's another reason why like besides it being a bulky base how else could we have noticed from the base um from the base like is it strong or is it weak oh strong strong okay I see saying yeah that's all that's
8:19
all I'm looking for so in this case the bulky base is really just saying this is bulky this portion but this is telling me oh there is a negative charge there right so this is going to be strong that's why it's E2 perfect and then yes you are correct this would have been Huffman's product anti-f and it's the less sub suited alken that is the major product that's true good let's increase the difficulty level now moving on to the next one okay this says label each reaction as sn1 sn2 E1
8:53
or E2 some reactions of course can have multiple answers then predict the product for each reaction okay let's start here let's just identify what it is this would be
Here to help you learn
Sign in to keep a private conversation with your course tutor.
Ask me anything about the material…
Sign in to chat