The rate of `SN^2` reaction depends on the effectiveness of the nucleophile in ejecting the leaving group. Nucleophilicity is the affinity for `C` atom, while basicity is the affinity for proton.

In both cases, a new bond is formed. If a new bond is formed between the anion and proton, the specied acts as a base. If a new bond is formed between the anion and `C` atom, the species acts as nucleophile.
Which of the following compounds gives `SN^1, SN^2`, and `SN^2` mechanisms ?

Options

A.
B.
C. Ph-I
D.

Answer

B

Explanation

(b) Allyl halide can undergo `SN^1, SN^2`, and `SN^2'` reactions.