question_answer 106)

  Aryl halides are extremely less reactive towards nucleophilic substitution. Predict and explain the   order of reactivity of the following compounds towards nucleophilic substitution :                             

Answer:

                  tert-Butyl bromide readily loses  ion to form stable fert-butyl carbocation. Therefore, it undergoes reaction by mechanism which occurs in two steps. In the first step, tert-butyl carbocation is formed. This step               is slow and hence is the rate determining step of the reaction. In the second step, the tert-butyl carbocation  is readily attacked by  ion to form tert-butyl alcohol.