SN2 reaction between azide ion and alkyl halides to give alkyl azides
Description: Alkyl halides (or tosylates) will react with azide ions (such as NaN3 or KN3) in an SN2 reaction to give alkyl azides.
Notes: X here is a halide (Cl, Br, I) or sulfonate (OTs, OMs)
Although Na is often shown as the counter-ion any alkali metal can also be used (e.g. Li, Na, K)
Notes: Note that since this is an SN2 reaction and proceeds via backside attack, there will be inversion of configuration at the carbon (note the last two examples).
Mechanisms: In the SN2 reaction the nucleophile (N3-) attacks the carbon with the good leaving group, forming a C–N bond and breaking the C–I bond (Step 1, arrows A and B).
Notes: For more information on the SN2 see the summary sheet on this reaction. For our purposes using Na or K is immaterial.