Why is SN2 mechanism chosen rather than SN1 in the preparation of primary alkyl halides?

Answer 1

In the preparation of primary alkyl halides, you usually create something more labile toward nucleophilic substitution than the halide itself.

SN1 is not a possible reaction pathway for the synthesis of a primary alkyl halide because primary carbocations are incredibly unstable ... they aren't formed. SN2 mechanisms proceed without an intermediate carbocation, which makes SN2 the predominant mechanism.

Answer 2

It isn't really a matter of choice at all. The reaction is (whether we like it or not) nucleophilic displacement of a leaving group from a primary site, and the fact is that this reaction proceeds by SN2, because it is not easy to form primary carbocations.

Answer 3

ahhh good question.

now i wish i was a physicist

then i could tell you.