# Which attack occurs first: nucleophilic acyl substitution or nucleophilic substitution?

If there is a compound with a site for nucleophilic acyl substitution (i.e. an ester group or the like) as well as a nucleophilic substitution (i.e. a bromine group or the like), will a nucleophile preferentially attack one of them? How do i decide which one a nucleophile would prefer attacking?

• Based on the fact that the pi bond is more reactive, in the sense that it is more easily broken, nucleophilic acyl substitution may be more kinetically favourable and would thus occur first. – Tan Yong Boon May 30 '18 at 13:51