Question

Predict in order of reactivity of the following compounds in $S_{N^1}and{S}_{N^2}$ reactions

$$\begin{gathered} 1)C_6{H}_{5}C{H}_{2}Br \\ 2)C_6{H}_{5}CH\left(C_6{H}_5\right)Br \\ 3)C_6{H}_{5}CH(C{H}_3)Br \\ 4)C_6{H}_{5}C\left(C{H}_3\right)\left(C_6{H}_5\right)Br \end{gathered}$$

Answer 1

Dear Student,

The order of reactivity are expressed below,

C₆H₅C(CH₃)(C₆H₅)Br > C₆H₅CH(C₆H₅)Br > C₆H₅CH(CH₃)Br > C₆H₅CH₂Br

​As per SN₁ and SN₂ the halide with 3 degree of highly reactive, followed by two degree and one degree halides where first degree is least stable based on it the increasing order are expressed above.

for S_N1 is 3 > 2 > 1
for S_N2 is 1 > 2 > 3

Regards.