nucleophilic addition

A nucleophilic addition is a chemical reaction where an atom or group of atoms is added to a molecule. This typically occurs with unsaturated organic compounds like alkenes and alkynes, which have carbon-carbon double or triple bonds, as well as aldehydes and ketones with carbon-oxygen double bonds.1

In this reaction, a nucleophile, which is an atom or molecule with an available electron pair, seeks a positive center. The nucleophile attacks the molecule, often at a carbon atom involved in a double bond. This breaks the double bond and allows the nucleophile to attach to the molecule, effectively saturating it with additional atoms or groups. This process is fundamental in organic chemistry for building more complex carbon skeletons.213