Haloalkanes and Haloarenes - Result Question 17
####17. Which of the following undergoes nucleophilic substitution exclusively by $S_N 1$ mechanism?
[2005]
(a) Ethyl chloride
(b) Isopropyl chloride
(c) Chlorobenzene
(d) Benzyl chloride
Show Answer
Solution:
- (d) $S_N 1$ reaction is favoured by heavy groups on the carbon atom attached to halogen i.e Benzyl $>$ allyl $>$ tertiary $>$ secondary $>$ primary $>$ alkyl halides
Obtained from $S_N 1$ path.
(Benzyl cation)
This molecule is resonance stabilised.
