chlorocarbonyls

Chlorocarbonyls are a class of organic compounds characterized by the presence of the chlorocarbonyl functional group, which has the general formula R-COCl. This group consists of a carbonyl group (C=O) bonded to a chlorine atom. Chlorocarbonyls are essentially acid chlorides, and they are highly reactive due to the electron-withdrawing nature of the chlorine atom, which makes the carbonyl carbon electrophilic.

The synthesis of chlorocarbonyls typically involves the reaction of a carboxylic acid with a chlorinating agent such as thionyl chloride (SOCl2), phosphorus trichloride (PCl3), or phosphorus pentachloride (PCl5). For example, acetic acid reacts with thionyl chloride to produce acetyl chloride.

Chlorocarbonyls are important intermediates in organic synthesis. They readily undergo nucleophilic acyl substitution reactions with a variety of nucleophiles. Reaction with alcohols yields esters, reaction with amines produces amides, and reaction with water generates the corresponding carboxylic acid. They are also used in Friedel-Crafts acylation reactions to introduce acyl groups onto aromatic rings. Due to their high reactivity, chlorocarbonyls are often prepared and used in situ or handled with care to avoid hydrolysis. They can be irritating and corrosive.