Question

Is there a formation of carbocation in both elimination reactions, E1 and E2?

Answer 1

No, a carbocation is formed only in `E1`eliminations.

In an `E1` elimination, the leaving group departs first to form an intermediate carbocation. Then a base attacks a β hydrogen in the carbocation to form the alkene.

In an `E2` elimination, the leaving group departs at the same time as the base attacks.

There is a single transition state that consists of both the base and the substrate.

At no time does a carbocation form in an `E2` elimination.