Orgo question - some help needed

[drteeth]

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Hey all,

In regard to the orgo section and the SN1/SN2/E1/E2 rxns. I was wondering if someone can provide me with a list of all the good to bad leaving groups, as well as the strong to weak nucleophiles and bases that are important in these reactions...

Thanks for your help🙂

 

[student1985]

Do you have the Kaplan book? If so, it has a nice list of good/bad leaving groups, as well as strong/weak nucleophiles and bases. I believe it was in the chapter dealing with SN1/SN2 reactions.

If you don't have the book, then read below:

SN1
Its leaving groups should be more acidic than the incoming nucleophile so that the nucleophile can attach. Examples of good leaving groups for SN1 (Br, Cl, I)
Nucleophile not too important

SN2
Leaving groups not important, only strong nucleophiles are (RO-, CN-) so they can displace the leaving group easily.

E1
Leaving Groups are very important; they should be weak acids (Br, Cl)
Bases not important; weak bases are OK (H2O, NH)

E2
Strong bases are required to displace the leaving group; Strong bases are (RO-, CN-, etc.)
Leaving groups should be acidic (Br, Cl)

hope this helps