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The Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877 to attach substituents to an aromatic ring. [1] Friedel–Crafts reactions are of two main types: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution. [2] [3] [4] [5]
While nucleophilic acyl substitution reactions can be base-catalyzed, the reaction will not occur if the leaving group is a stronger base than the nucleophile (i.e. the leaving group must have a higher pK a than the nucleophile). Unlike acid-catalyzed processes, both the nucleophile and the leaving group exist as anions under basic conditions.
Oxalyl chloride reacts with aromatic compounds in the presence of aluminium chloride to give the corresponding acyl chloride in a process known as a Friedel-Crafts acylation. [ 15 ] [ 16 ] The resulting acyl chloride can be hydrolysed to form the corresponding carboxylic acid .
Freund reaction; Friedel–Crafts acylation; Friedel–Crafts alkylation; Friedländer synthesis; Fries rearrangement; Fritsch–Buttenberg–Wiechell rearrangement; Fujimoto–Belleau reaction; Fujiwara–Moritani reaction; Fukuyama coupling; Fukuyama indole synthesis; Fukuyama reduction
In chemistry, acylation is a broad class of chemical reactions in which an acyl group (R−C=O) is added to a substrate. The compound providing the acyl group is called the acylating agent. The substrate to be acylated and the product include the following: alcohols, esters; amines, amides; arenes or alkenes, [1] ketones
It can be used to promote reactions of carboxylic acids, including Friedel-Crafts acylation and acylation of other unsaturated compounds. Other electrophilic aromatic substitution reactions can also be promoted with trifluoroacetic anhydride, including nitration, sulfonation and nitrosylation. [2]
This hydrolysis is the most heavily exploited reaction for acyl halides as it occurs in the industrial synthesis of acetic acid. an alcohol to form an ester; an amine to form an amide; an aromatic compound, using a Lewis acid catalyst such as AlCl 3, to form an aromatic ketone. [7] See Friedel-Crafts acylation.
In the Friedel–Crafts acylation, acid halides act as electrophiles for electrophilic aromatic substitution. A Lewis acid – such as zinc chloride (ZnCl 2), iron(III) chloride (FeCl 3), or aluminum chloride (AlCl 3) – coordinates to the halogen on the acid halide, activating the compound towards nucleophilic attack by an activated aromatic ...