SN1 SN2 E1 E2

primary carbon

-SN2: good L.G.'s & good nuc.

-E2: strong, bulky bases

secondary carbon

-SN1/E1: good L.G.'s & poor nuc.

-SN2: good L.G.'s & good nuc.

-E2: good L.G.'s & good nuc.; favored w/ strong bases

tertiary carbon

-SN1/E1: good L.G.'s & good/poor nuc.

-E2: strong bases

good leaving groups

I-, Br-, Cl-, H2O, -OSO2R, ROH, N2, NR3, SR2

poor leaving groups

-OH, -OR, -NH2, -NHR, -NR2, -F (strong bases)

good nucleophiles

I-, RS-, CN-, N3-

strong bases (good nuc. & poor L.G.'s)

-OH, -OR, -NH2, -NR2

weak nucleophiles

H2O, ROH, RCO2H, F-

acid catalyzed dehydration of 2° and 3° alcohols

-expect to see heat

-E1: major pathway