Hey,
How do you identify between a nucleophilic . electrophilic reactions ? Meaning liking substitutions, eliminations, and additions.
Thanks
reactions themselves aren't nucleophilic or electrophilic. you hear of electrophilic aromatic substitution, nucleophilic aromatic substitution, electrophilic addition across an alkene, etc., but that's not saying that the reaction is nucleophilic or electrophilic. for example:
electrophilic aromatic substitution:
the name implies that you're using an electrophile to substitute something in an aromatic molecule. the aromatic ring is the nucleophile (because it donates an electron pair to the electrophile in the first step) and the new substitutent you're attaching is the electrophile because it accepts the electron pair.
for nucleophilic aromatic substitution:
the aromatic ring is now an electrophile, because a nucleophile (the one you're substituting into the ring) donates an electron pair to the ring.
for electrophilic addition across an alkene:
let's take Br2 addition, so the two electrons in the double bond attack the Br2, so the Br2 accepts a pair of electrons in the first step. so Br2 functions as an electrophile.
so it's all about your frame of reference. for aromatic substitution, since you're generally thinking about it from the standpoint of the aromatic ring, you call it nucleophilic or electrophilic substitution depending on the way you're substituting it. if you're subbing in an electrophile, then it's EAS. if you're subbing in a nucleophile, it's NAS.
