Question

Which of the following nucleophiles is going to promote an $S_{N^2}$ reaction?

• A. NaI
• B. Water
• C. $N{H}_{4}Cl$
• D. MeONa

Answer 1

The correct option is A NaI

The $S{N}^2$ reactions tend to proceed with strong nucleophiles; by this, generally means negatively charged nucleophiles such as $I^{-},C{H}_3{O}^{-},C{N}^{-},RS-,N_3-,H{O}^{-}$, and others.

The $S{N}^1$ tends to proceed with weak nucleophiles – generally neutral compounds such as solvents like $C{H}_{3}OH,H_{2}O,C{H}_{3}C{H}_{2}OH$

In the given options only $NaI$ has $I^{-}$ a negative nucleophile.So $NaI$ promotes $S{N}^2$ reaction mechanism.

Hence option A is correct.