A highly reactive substance that replaces hydrogen by an alkyl group especially in a biologically important molecule (e.g. DNA).
Alkylating agents are grouped into nucleophilic and electrophilic:
- nucleophilic alkylating agents - the use of organometallic compounds such as Grignard (organomagnesium), organolithium, organocopper, and organosodium reagents.
- electrophilic alkylating agents - the use of alkyl halides with a Lewis acid catalyst to alkylate aromatic substrates in Friedel-Crafts reactions.
Alkylating agents are used clinically by inhibiting cell division and growth, thus, are used to treat some cancers. Alkylated DNA either does not coil or uncoil properly, resulting in cytotoxicity that further leads to cell growth inhibition and initiation of apoptosis.
See also: alkylation