Radical Substitution - Radical Substitution Reactions

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