Chemistry - Halogen Derivative Question with Solution | TestHub

The electronegativity order of hybridized carbons is$\mathrm{s}\mathrm{p}>\mathrm{s}{\mathrm{p}}^2>\mathrm{s}{\mathrm{p}}^3$. So in an allylic halide, such as$\mathrm{C}{\mathrm{H}}_2=\mathrm{C}\mathrm{H}-\mathrm{C}{\mathrm{H}}_2-\mathrm{I}$, the alpha carbon is much more partially positive than the alpha carbon in$\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2-\mathrm{C}{\mathrm{H}}_2\mathrm{I}$. Therefore, the attacking nucleophile will be attracted to the alpha carbon more in the allylic halide compound than in the primary halide. Hence, allylic halides tend to follow${\text{S}}_{\text{N}}\text{2}$pathways more than primary halides.