SN2 vs E2 vs SN1 vs E1

[EnginrTheFuture]

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In my orgo class, we learned a very nice elaborate web of conditions that leads the likely mechanism to be preferred. This was nice and all and it worked for my first run through the practice problems but it is hard to remember long-term and causes me to take more time than I would like on these types of problems.

Was anyone taught, or figured out on their own, a more clever or convenient way to remember what reaction conditions favor SN2 vs E2 vs E1 vs SN1. Better yet, does anyone have a clever way of determining what is considered a strong base/weak nucleophile vs strong base/strong nucleophile.

Thanks for the help!

 

[MedPR]

There are lots of lists of strong bases and weak bases.. You just need to memorize them for the most part.

SN2 = strong nucleophile, aprotic solvent, non-tertiary substrate.
E2 = strong base, aprotic solvent, anti-periplanar substrate
SN1 = weak nucleophile, protic solvent, non-primary substrate
E1 = weak base, protic solvent, any substrate (I think)

 

[chiddler]

There are lots of lists of strong bases and weak bases.. You just need to memorize them for the most part.

SN2 = strong nucleophile, aprotic solvent, non-tertiary substrate.
E2 = strong base, aprotic solvent, anti-periplanar substrate
SN1 = weak nucleophile, protic solvent, non-primary substrate
E1 = weak base, protic solvent, any substrate (I think)

e1 is also non primary substrate. remember first step for both is dissociation of LG