Preferred Label : leaving group;
IUPAC definition : An atom or group (charged or uncharged) that becomes detached from an atom in what
is considered to be the residual or main part of the substrate in a specified reaction.
For example, in the heterolytic solvolysis of benzyl bromide in acetic acid: the
leaving group is Br sup class minus /sup ; in the reaction: the leaving group is
NMe sub 3 /sub ; in the electrophilic nitration of benzene, it is H sup class plus
/sup . The term has meaning only in relation to a specified reaction. The leaving
group is not, in general, the same as the substituent group present in the substrate
(e.g. bromo and trimethylammonio in the substrates of the first two examples above).
A slightly different usage of the term prevails in the (non-mechanistic) naming of
transformations, where the actual substituent group present in the substrate (and
also in the product) is referred to as the leaving group.;
Origin ID : L03493;
See also
An atom or group (charged or uncharged) that becomes detached from an atom in what
is considered to be the residual or main part of the substrate in a specified reaction.
For example, in the heterolytic solvolysis of benzyl bromide in acetic acid: the
leaving group is Br sup class minus /sup ; in the reaction: the leaving group is
NMe sub 3 /sub ; in the electrophilic nitration of benzene, it is H sup class plus
/sup . The term has meaning only in relation to a specified reaction. The leaving
group is not, in general, the same as the substituent group present in the substrate
(e.g. bromo and trimethylammonio in the substrates of the first two examples above).
A slightly different usage of the term prevails in the (non-mechanistic) naming of
transformations, where the actual substituent group present in the substrate (and
also in the product) is referred to as the leaving group.
