Alquilación deFriedel-Craft HELEN MORALES SEBASTIAN ROCHA ALEX VILLAMIL La alquilación de Friedel-Craft es la adición de grupos alquilo a un. Obtencion de 2-fenil lepidinas durante la alquilacion de friedel-crafts asistida por microondas de N-([alfa]-alilbendl) anilinas soportadas en silica-acido sulfurico. The purpose of this experiment is to perform a Friedel-Crafts alkylation using two different methods on two different aromatic compounds. A Friedel-Crafts.
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Reacciones de Friedel y Crafts by Cid Alejandro Almazán González on Prezi
Berichte der deutschen chemischen Gesellschaft. The Haworth reaction is a classic method for the synthesis of 1-tetralone. The Friedel—Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in to attach substituents to an aromatic ring.
The net result is the same as the Friedel—Crafts alkylation except that rearrangement is not possible. Reactions, Mechanisms, and Structure 6th ed.
Also, there are no carbocation rearrangements, as the acylium ion is stabilized by a resonance structure in which the positive charge is on the oxygen. Replacing resorcinol by N,N-diethylaminophenol in this reaction gives rhodamine B:. Secondly, the Friedel-Crafts alkylation reaction crqfts conducted with anhydrous Fe[Cl.
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. Asymmetric Functionalization of C-H Bonds.
Alkylations are not limited to alkyl halides: This reaction has several advantages over the alkylation reaction.
Friedel—Crafts acylation involves the acylation of aromatic rings. Examples are given below of the interaction of benzene with the ethyl chloride and the acid chloride of acetic acid: Both proceed by electrophilic aromatic substitution. The general mechanism is shown below. An electrophilic substitution of a proton on the aromatic ring by a halogenated alkane or olefin can be realized in the presence of a strong Lewis acid, which is known as the Friedel-Crafts alkylation reaction .
Friedel-Crafts alkylation is used in industry to produce high-octane fuels, antioxidants, surfactants, perfumes, ethylbenzene starting material in styrene manufactureand other important products, such as cumene and thymol. 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.
The Friedel-Crafts reaction was discovered by C.
Due to the electron-withdrawing effect of the carbonyl group, the ketone product is always less reactive than the original molecule, so multiple acylations do not occur. Friedel—Crafts acylation is also possible with acid anhydrides.
This reaction suffers from the disadvantage that the product is more nucleophilic than the reactant. If desired, the resulting ketone can be subsequently reduced to the corresponding alkane substituent by either Wolff—Kishner reduction or Clemmensen friedwl.
However, the actual reaction product is 1,3,5-triethylbenzene with all alkyl groups as a meta substituent. Typical Lewis acid catalysts are acids and aluminium trichloride. Catalytic asymmetric Friedel-Crafts alkylations. Friedel—Crafts alkylation has been hypothesized to be reversible.
For example, in a multiple addition of ethyl bromide to benzeneortho and para substitution is expected after the first monosubstitution step because an alkyl group is an activating group. 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.
Craftd Friedel James Crafts. As usual, the aldehyde group is more reactive electrophile than the phenone.
Furthermore, the reaction is only very useful for tertiary alkylating agents, some secondary alkylating agents, or ones that yield stabilized carbocations e. The general reaction of Friedel-Crafts alkylation reactions is 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.