Friedel-Crafts Reaction

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Friedel-Crafts reaction

[frē¦del ′krafs rē‚ak·shən]
(organic chemistry)
A substitution reaction, catalyzed by aluminum chloride in which an alkyl (R‒) or an acyl (RCO‒) group replaces a hydrogen atom of an aromatic nucleus to produce hydrocarbon or a ketone.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Friedel-Crafts Reaction

 

a method of alkylating and acylating aromatic compounds in the presence of acidic catalysts, such as AlCl3, BF3, ZnCl2, FeCl3, mineral acids, oxides, and cation-exchange resins. The alkylating agents used are alkyl ha-lides, olefins, alcohols, and esters. The acylating agents include carboxylic acids and their acid halides and their anhydrides.

The Friedel-Crafts reaction is a typical electrophilic substitution reaction in the aromatic nucleus; the role of the catalyst amounts to the generation of an attacking particle—an alkyl or acyl cation.

Examples are given below of the interaction of benzene with the ethyl chloride and the acid chloride of acetic acid:

Friedel-Crafts alkylation is used in industry to produce high-octane fuels, antioxidants, surfactants, perfumes, ethylbenzene (starting material in styrene manufacture), and other important products, such as cumene and thymol. Friedel-Crafts acylation is a basic method of synthesizing aromatic and aliphatic-aromatic ketones, many of which are intermediate products in the manufacture of pharmaceuticals and various dyes, such as Michler’s ketone.

The Friedel-Crafts reaction was discovered by C. Friedel and J. Crafts in 1877–78.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Although numerous methologies of indole derivation were explored, the general methods for Friedel-Crafts alkylation of heteroaromatic compounds with activated carbonyl compounds to form C-C bond reactions are still in demand.
Feng, Highly Enantioselective Zinc-Catalyzed Friedel-Crafts Alkylation of Indoles with Ethyl Trifluoropruvate, Adv.
This includes polypropylenes, ethylenepropylene copolymers, polyisobutylenes, polydienes, propylene-based elastomers or ethylene-based plastomers Grafting occurs by Friedel-Crafts alkylation of solutions in special reactors.
Secondly, the Friedel-Crafts alkylation reaction was conducted with anhydrous Fe[Cl.sub.3] as catalyst.
The imidazolium salts functional hypercrosslinked polymers (ILHCPs) were synthesized via the free radical cross-linking copolymerization and Friedel-Crafts alkylation reaction (shown in Scheme 1).
They cover asymmetric C-H bond insertion reactions, symmetric cross-dehydrogenative coupling reactions, asymmetric oxidative biaryl coupling reactions, asymmetric [1,5]-hydride transfer reactions, asymmetric functionalization of C-H bonds via a transient carbon-metal species, asymmetric Friedel-Crafts alkylation reactions, N-heterocyclic carbene-catalyzed asymmetric functionalization of aldehyde C-H bonds, asymmetric hydroacylation reactions, and asymmetric hydrovinylation reactions.
In the presence of Al[Cl.sub.3] catalyst, the PS-graft-POE copolymer is formed by Friedel-Crafts alkylation in PS/POE blends, which strengthens the interaction between molecules and limits the macromolecular chain movement.
Microwave accelerated facile synthesis of fused polynuclear hydrocarbons in dry media by intramolecular Friedel-Crafts alkylation. Organic & Biomolecular Chemistry 2, 514-523.
Discovered in 1877, and its versatility exploited widely since then, Friedel-Crafts alkylation is well-covered in numerous comprehensive treatises; but editors Bandini and Umani-Ronchi (both affiliated with the U.
Other projects explore preparative and mechanistic aspects of heterogeneous organic reactions such as Friedel-Crafts alkylation catalyzed by silica gel, aldol condensation catalyzed by zeolites, ether formation from sterically hindered alcohols through phase-transfer catalysis, and oxidations with solid-supported reagents.
Friedel-Crafts alkylation of mesylate or tosylate with isobutylbenzene for single step synthesis of ethyl-2-(4-isobutylphenyl) propanoate was carried out by heating with Silica-Supported Preyssler Nanoparticles ([H.sub.14][Na[P.sub.5][W.sub.30][O.sub.110]]/Si[O.sub.2]) (SPNPs) under neat reaction conditions.