SN2 Reaction of Acetylide Ions with Alkyl Halides
Description: Alkyl halides treated with acetylide ions (the conjugate bases of acetylenes) will undergo SN2 reactions to give alkynes.
Notes: This works best for primary or methyl alkyl halides. Sodium (Na) is not crucial, it’s just a spectator ion.
Notes: Note how this works best for primary (or methyl) alkyl halides. With secondary alkyl halides, elimination reactions are more likely.
Mechanism: Acetylide ions are great nucleophiles. They will perform SN2 reactions on alkyl halides (Step 1, arrows A and B).
Notes: Really important! There aren’t many ways of making C–C bonds in Org 1, but this is one of them. This is one of the most USEFUL ways of making C–C bonds. Furthermore, alkynes are really versatile and can be turned into all kinds of other things.