In organic and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of atoms called the leaving group; the positive or partially positive atom is referred to as an electrophile.
The most general form for the reaction may be given as
The electron pair (:) from the nucleophile (Nuc) attacks the substrate (R-LG) forming a new bond, while the leaving group (LG) departs with an electron pair. The principal product in this case is R-Nuc. The nucleophile may be electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged.
An example of nucleophilic substitution is the hydrolysis of an alkyl bromide, R-Br, under alkaline conditions, where the attacking nucleophile is the OH− and the leaving group is Br-.
- R-Br + OH− → R-OH + Br−
Nucleophilic substitution reactions are commonplace in organic chemistry, and they can be broadly categorised as taking place at a saturated aliphatic carbon or at (less often) a saturated aromatic or other unsaturated carbon centre.
Other articles related to "nucleophilic substitution, nucleophilic, substitution, substitutions, nucleophilic substitutions":
... The OH group is not a good leaving group in nucleophilic substitution reactions, so neutral alcohols do not react in such reactions ... protonated to give R−OH2+, the leaving group (water) is much more stable, and the nucleophilic substitution can take place ... the hydroxyl group is replaced by a chlorine atom by unimolecular nucleophilic substitution ...
... Nucleophilic substitution happens when the reagent is a nucleophile, which means, an atom or molecule with free electrons ... A nucleophile reacts with an aliphatic substrate in a nucleophilic aliphatic substitution reaction ... These substitutions can be produced by two different mechanisms unimolecular nucleophilic substitution (SN1) and bimolecular nucleophilic substitution (SN2) ...
... Nucleophilic substitution via the SN1 or SN2 mechanism does not generally occur with vinyl or aryl halides or related compounds ... Under certain conditions nucleophilic substitutions may occur, via other mechanisms such as those described in the nucleophilic aromatic substitution article ... When the substitution occurs at the carbonyl group, the acyl group may undergo nucleophilic acyl substitution ...
Famous quotes containing the word substitution:
“Virtue is the adherence in action to the nature of things, and the nature of things makes it prevalent. It consists in a perpetual substitution of being for seeming, and with sublime propriety God is described as saying, I A.”
—Ralph Waldo Emerson (18031882)