E1 Reaction
A two-step elimination proceeding through a carbocation, which then loses a proton to form an alkene.
Formula / equation
rate = k[substrate]
Unit
s⁻¹
In depth
E1 shares its rate-determining ionisation step with SN1, so the two always compete and the same conditions favour both: tertiary substrates, polar protic solvents, weak bases and heat. Higher temperature and a weaker nucleophile tip the balance towards elimination.
Examples in the real world
Heating 2-methylpropan-2-ol with concentrated sulfuric acid to give 2-methylpropene.