Question
Explain reactivity order towards $SN^2$ reaction of alkyl halides.

Answer

$\rightarrow$ Reactivity order of primary secondary and tertiary halides toward $SN^2$ reaction is $CH_3-X > 1^\circ -$ halide $>$ $2^\circ -$ halide $> 3^\circ -$ halide.
$\rightarrow$ The presence of bulky substituents on or near the carbon atom have a dramatic inhibiting effect.
$\rightarrow$ Of the simple alkyl halides, methyl halides react most rapidly in $SN^2$ reactions because there are only three small hydrogen atoms.
$\rightarrow$ Tertiary halides are the least reactive because bulky groups hinder the approach nucleophiles.
$\rightarrow$ Thus, the order of reactivity followed is: Primary halide $>$ Secondary halide $>$ Tertiary halide.
Image
Image

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free