Question

Arrange the following halo compounds in decreasing order of reactivity towards SN1 nucleophilic substitution reaction.
Vinyl chloride , Benzyl chloride , Iso propyl chloride

Answer 1

Dear student,


The order of stability of carbocation is:

allyl carbocation > n-propyl carbocation > vinyl carbocation

Therefore, the decreasing order of reactivity towards nucleophilic substitution reactions is

allyl chloride > n-propyl chloride > vinyl chloride

Allyl carbocation is resonance stabilized; n-propyl carbocation is stabilized by inductive effect whereas the vinyl cation is unstable due to positive charge on double bonded carbon.
Order:
benzyl chloride > iso-propyl chloride > vinyl chloride

Regards