The E1 reaction - A Nucleophilic Elimination in which the Rate Determining Step involves 1 component.
-E1 reactions are stepwise and unimolecular, proceeding throught an intermediate carbocation.
-E1 reactions do proceed through an intermediate. -The first step is slower and therefore determines the rate.
-Note that elimination and substitution are often competing reactions.
-E1 reactions are preferential with a weak base.