Preferred Label : ambident;
IUPAC definition : A description applied to a chemical species whose molecular entities each possess
two alternative and strongly interacting distinguishable reactive centres, to either
of which a bond may be made in a reaction: the centres must be connected in such a
way that reaction at either site stops or greatly retards subsequent attack at the
second site. The term is most commonly applied to conjugated nucleophiles, for example
the enolate ion: (which may react with electrophiles either at the β-carbon atom
or at oxygen) or γ-pyridones, and also to the vicinally ambident cyanide ion, cyanate
ion, thiocyanate ion, sulfinate ion, nitrite ion and unsymmetrical hydrazines. Ambident
electrophiles are exemplified by carboxylic esters div class chemoverlay pop pop1
img A00258-2.png RC( O)OCR sub 3 /sub /div which react with nucleophiles either
at the carbonyl carbon or the alkoxy carbon. Molecular entities, such as dianions
of dicarboxylic acids, containing two non-interacting (or feebly interacting) reactive
centres, are not generally considered to be ambident and are better described as 'bifunctional'.
The Latin root of the word implies two reactive centres, but the term has in the past
also incorrectly been applied to chemical species with more than two reactive centres.
For such species the existing term 'polydent' (or, better, 'multident') is more appropriate.;
Origin ID : A00258;
See also
A description applied to a chemical species whose molecular entities each possess
two alternative and strongly interacting distinguishable reactive centres, to either
of which a bond may be made in a reaction: the centres must be connected in such a
way that reaction at either site stops or greatly retards subsequent attack at the
second site. The term is most commonly applied to conjugated nucleophiles, for example
the enolate ion: (which may react with electrophiles either at the β-carbon atom
or at oxygen) or γ-pyridones, and also to the vicinally ambident cyanide ion, cyanate
ion, thiocyanate ion, sulfinate ion, nitrite ion and unsymmetrical hydrazines. Ambident
electrophiles are exemplified by carboxylic esters div class chemoverlay pop pop1
img A00258-2.png RC( O)OCR sub 3 /sub /div which react with nucleophiles either
at the carbonyl carbon or the alkoxy carbon. Molecular entities, such as dianions
of dicarboxylic acids, containing two non-interacting (or feebly interacting) reactive
centres, are not generally considered to be ambident and are better described as 'bifunctional'.
The Latin root of the word implies two reactive centres, but the term has in the past
also incorrectly been applied to chemical species with more than two reactive centres.
For such species the existing term 'polydent' (or, better, 'multident') is more appropriate.
