Radical Substitution Reactions
In free radical halogenation reactions radical substitution takes place with halogen reagents and alkane substrates. Another important class of radical substitutions involve aryl radicals. One example is the hydroxylation of benzene by Fenton's reagent. Many oxidation and reduction reactions in organic chemistry have free radical intermediates, for example the oxidation of aldehydes to carboxylic acids with chromic acid. Coupling reactions can also be considered radical substitutions. Certain aromatic substitutions takes place by radical-nucleophilic aromatic substitution. Auto-oxidation is a process responsible for deterioration of paints and food and lab hazards such as diethyl ether peroxide.
More radical substitutions are listed below:
- The Barton-McCombie deoxygenation is a way to substitute a hydroxyl group for a proton.
- The Wohl-Ziegler reaction involves the allylic bromination of alkenes.
- The Hunsdiecker reaction converts silver salts of carboxylic acids to alkyl halides.
- The Dowd-Beckwith reaction involves ring expansion of cyclic β-keto esters.
- The Barton reaction involves synthesis of nitrosoalcohols from nitrites.
- The Minisci reaction involves generation of an alkyl radical from a carboxylic acid and a silver salt and subsequent substitution at an aromatic compound
Read more about this topic: Radical Substitution
Famous quotes containing the words radical, substitution and/or reactions:
“When we dream about those who are long since forgotten or dead, it is a sign that we have undergone a radical transformation and that the ground on which we live has been completely dug up: then the dead rise up, and our antiquity becomes modernity.”
—Friedrich Nietzsche (1844–1900)
“To play is nothing but the imitative substitution of a pleasurable, superfluous and voluntary action for a serious, necessary, imperative and difficult one. At the cradle of play as well as of artistic activity there stood leisure, tedium entailed by increased spiritual mobility, a horror vacui, the need of letting forms no longer imprisoned move freely, of filling empty time with sequences of notes, empty space with sequences of form.”
—Max J. Friedländer (1867–1958)
“In this Journal, my pen is a delicate needle point, tracing out a graph of temperament so as to show its daily fluctuations: grave and gay, up and down, lamentation and revelry, self-love and self-disgust. You get here all my thoughts and opinions, always irresponsible and often contradictory or mutually exclusive, all my moods and vapours, all the varying reactions to environment of this jelly which is I.”
—W.N.P. Barbellion (1889–1919)