Question

Which Sn reaction is least reactive?

Answer 1

Nucleophilic Substitution Reaction

${\mathrm{CH}}_2=\mathrm{CHCl}$ is considered less reactive in nucleophilic substitution reactions. Because of its charge and partial double bond with carbon, the chlorine atom is strongly attracted to the nucleus. As a result, it is not replaced with nucleophile in the S_N reaction.