Question

Which of the following is least reactive in a nucleophilic substitution reaction?

• A. $C{H}_2=CHCl$
• B. $C{H}_{3}C{H}_{2}Cl$
• C. $C{H}_2=CHC{H}_{2}Cl$
• D. $(C{H}_3{)}_{3}C-Cl$

Answer 1

The correct option is A $C{H}_2=CHCl$

Vinyl chloride in option $A$ is least reactive in the nucleophilic substitution reaction as the carbocation formed is least stable. The positive charge is on the more electronegative $C$ atom ($s{p}^2$ hybridized carbon atoms.). In option $B$, the carbocation formed has positive charge on less electronegative $C$ atom ($s{p}^3$ hybridized carbon atom). In $C$, the carbocation formed is resonance. In $D$, tertiary carbocation is formed which is more stable.