7.7 How to Distinguish Between Substitution and Elimination Reactions (SN2 SN1 E2 E1) | OChem

Chad begins this lesson comparing SN2, SN1, E2, and E1 reactions. Based upon the differences between substitution and elimination reactions, he then develops the method for how to predict the products of substitution and elimination reactions and how to distinguish between SN2, SN1, E2, and E1 reactions. SN1 and SN2 reactions were covered at length earlier in the chapter with a lesson showing how the nucleophile, substrate, and solvent can be used to predict the major substitution product (SN1 vs SN2). E1 and E2 reactions were also covered at length with a lesson showing how the base, substrate, and solvent can be used to predict the major elimination product (E1 vs E2). Now, Chad compares and contrasts SN2, SN1, E2, and E1 reactions simultaneously in terms of the nucleophile/base, substrate, and solvent and how the differences can be used to predict which of these reactions are likely to occur so that the major and minor products can be determined. He provides an SN1, SN2, E1, E2 chart that outlines what substitution and/or elimination reaction mechanism is likely based upon the combination of the particular substrate and nucleophile/base being used. Chad works five substitution and elimination practice problems to demonstrate how the chart is used to determine the major products.

00:00 Lesson Introduction
00:36 Comparing and Contrasting SN1, SN2, E1, E2
04:22 How to Predict the Products Example #1
06:13 How to Predict the Products Example #2
08:06 How to Predict the Products Example #3
09:17 How to Predict the Products Example #4
11:10 How to Predict the Products Example #5

[ksubra]

Some people who are very knowledgeable can't teach, and this happens to be the case with a lot of professors. Glad there are people like you out there making entire courses for subjects like this, for free - these videos are a lifesaver.

[matthewguerrero]

Chad, over the years of taking chemistry, I have found your videos a great resource and it has helped me learn concepts in minutes that would have otherwise taken hours. Thank you for creating this channel. Don't ever stop creating content!

[xXnutriaXx]

I’m watching this 30 minutes before my exam and it’s making so much sense!

[marianne_helena]

Thank you for all of these videos!! I finally understand this and feel confident about taking the OAT next week. Thank you Chad for making Organic Chemistry make sense and also somewhat enjoyable!!

[victoriai]

Hi Chad. I found your videos over a first year chemistry groupchat with students in my university class and since then, I have not stopped coming to your channel for these resources. I just wanted to say thank you for making these videos and for making this a resource available to everyone. God bless you and I hope you have been well.

[bryced]

Chad your channel and website are awesome. Give it some time and you will be one of the biggest chemistry youtubers out there. Thank you!

[mariaannovi]

Best video out there explaining substitution and elimination reactions. Thank you so much for making tricky subjects enjoyable to learn!

[ertyh]

you are the best Chad. Your explanations are really simple to understand. Thank you so so so much.

[naufalhanifkusuma]

O man your explanation really handy and easy to remember, you help me a lot at organic exam, 3000 thank you for you chad!

[reymundodeleon]

For the first example, would the reaction mainly favor elimination because there is heat involved? (delta symbol)

[hetmantermigen]

sorry for the question but why in the reaction of minute 8:02 it follow hofman rule and not zaitsev's rule and in the last reaction it follows the zaitesv's one ?

[raeanne]

im so sorry for the dumb question but for time stamp 12:13 you called that carbon a tertiary carbon, I am a bit confused on how that is tertiary? I took it as a secondary carbon and looking at the chart you'd still get e2 for your major product but could you please explain it a bit? Does the "Ph" have anything to do with that? I have never seen that before in these types of problems. I also just seem to struggle in general when questions have the structures showing stereochemistry like that haha

[hanainyousaff]

so much for the amazing lectureee....🎉

[jansentanu]

For the last example, why does the E2 reaction not occur on the primary beta carbon?

[baboom]

Hi at 9:55 why is one the leaving group and other is not ?

[bapiful]

Hi Chad, at 6:50 for E2 reaction why are we not first checking if the leaving group and hydrogen are anti peri-planar? Is there an exception to this rule for alkanes that are not in a ring? And thank you so much for making these videos, they are extremely helpful and I hope you gain more viewers!

[fatemehebrahimi]

Thank you for organic chemistry .It was really helpful for me

[furycapricorn]

Really good video, but the way my professor taught this made this so much more confusing. He didn't even provide practice problems in the style he taught it. I guess learning this more in-depth may help me later on down the line. Just hoping the final doesn't get too confusing

[호호잇-hc]

Hi Chad
Where does CH3CO2- belong in?
Is it strong nuc/strong base because it is RO- ??

[david.the.disaster]

How do you identify a strong vs a weak base? For example why is potassium tert-butoxide a strong base?