Which alkyl halide from the following pairs would you expect to react more rapidly by an S_N2 mechanism? Explain your answer.

Question

Which alkyl halide from the following pairs would you expect to react more rapidly by an S N 2 mechanism? Explain your answer. (i) (ii) (iii)

Philoid · Accepted Answer

In S_N2 Reaction, the product will be formed in a single step with no intermediates. Nucleophile attack will be easier for simple halides than hindered haloalkanes. Therefore,

Because of this in S_N2

i) Bromobutane (1°)reacts faster than 2-Bromobutane(2°)

ii) 2-Bromobutane(2°) reacts faster than 2-Bromo-2-methylpropane or tert-Butyl bromide (3°)

iii) 1-Bromo-3-methyl butane reacts faster than the 1-Bromo-2-methyl butane as the former is less hindered with respect to leaving halide than the later which is more hindered comparatively.

Which alkyl halide from the following pairs would you expect to react more rapidly by an SN2 mechanism? Explain your answer.(i) (ii) (iii)

Which alkyl halide from the following pairs would you expect to react more rapidly by an S_N2 mechanism? Explain your answer.
(i)

(ii)

(iii)