An ambident nucleophile is a type of nucleophile that can form new bonds at two or more spots in its structure, usually due to resonance contributors. It is an anionic species whose negative charge is delocalized by resonance on two unlike atoms or two like but non-equivalent atoms, and they act as two different nucleophilic centers. Ambident nucleophiles can execute nucleophilic attacks from two or more different places in the molecule or ion, resulting in the formation of more than one product.

Examples of ambident nucleophiles include:

• Thiocyanate ion (SCN-): It can execute nucleophilic attacks from either the sulfur atom or the nitrogen atom, resulting in the formation of a mixture of alkyl isothiocyanates and alkyl thiocyanates.
• Cyanide ion (CN-): It can attack through the carbon atom or the nitrogen atom, resulting in the formation of two different products.
• Nitrite ion (NO2-): It can attack through oxygen resulting in the formation of alkyl nitrites, or it can attack through nitrogen resulting in the formation of nitroalkanes.

Ambident nucleophiles are important in organic chemistry because they can lead to the formation of multiple products, which can be useful in the synthesis of complex molecules.