What is the difference between an electrophilic substitution reaction and a nucleophilic substitution reaction?

1 Answer
Oct 25, 2016

As the name implies, one involves replacement of a leaving group by an electrophile, the other involves replacement of a leaving group with a nucleophile.

Explanation:

Substitution reactions involve one atom/group in a molecule being replaced by another; the one that is replaced being known as the "leaving group". This is distinct from "addition" reactions in which a species adds onto a molecule, but doesn't replace a leaving group.

Electrophilic substitutions involve displacement of a functional group by an electrophile (generally a hydrogen atom). Electrophiles are species that are attracted to electrons.

Nucleophilic substitutions involve attack of a positively charged (or partially positively charged) atom or group by a nucleophile. Nucleophiles are species that can donate an electron pair.