Acylation Of Aromatic Compounds Research Articles

Friedel-Crafts Reactions Catalyzed by Rare Earth Metal Trifluoromethanesulfonates

Abstract Rare earth metal trifluoromethanesulfonates (rare earth metal triflates, RE(OTf)3) were found to be efficient catalysts for Friedel-Crafts acylation and alkylation. In the presence of a catalytic amount of RE(OTf)3, acylation of aromatic compounds having electron-donating substituents such as anisole, thioanisole, and mesitylene with acid anhydrides proceeded smoothly to afford the corresponding aromatic ketones in high yields. Although RE(OTf)3 alone is not effective for acylation of less reactive aromatics such as toluene, the combination of RE(OTf)3 and lithium perchlorate (LiClO4) enhanced the catalytic activity dramatically. Friedel-Crafts acylation reactions using rare earth metal perfluoroalkanesulfonates were also successfully performed in supercritical carbon dioxide (scCO2). Moreover, in the presence of a catalytic amount of RE(OTf)3, aromatic compounds reacted with benzyl chloride smoothly to afford the corresponding alkylation products in high yields. In these reactions, RE(OTf)3 could be easily recovered after the reactions were completed and could be reused without loss of activity.

Highly active Si-MCM-41-supported Ga 2O 3 and In 2O 3 catalysts for friedel-crafts-type benzylation and acylation reactions in the presence or absence of moisture

Ga2O3 and In2O3 (which are amphoteric and basic in nature, respectively) supported on mesoporous Si-MCM-41, or even on micro- or macroporous inert catalyst carriers, are highly active and reusable catalysts for the benzylation of benzene and acylation of aromatic compounds, even in the presence of moisture. Moisture has a beneficial effect, more particularly for the acylation reaction. It causes an increase in the reaction rates for both the reactions and also a large increase in the induction period for the benzylation reaction but not for the acylation. The induction period is due to the presence of moisture adsorbed on the catalyst, which is to be replaced by the reactant(s) to start the catalytic reaction.

Acylation of aromatic compounds on H-Beta zeolites

Friedel–Crafts acylation of anisole by acetic anhydride and the Fries rearrangement of phenyl acetate were investigated in the liquid phase using the H-form of various zeolites. Zeolite Beta was found to be the most active catalyst for acylation reactions compared to Y- and ZSM-5 zeolites. The reactions were found to be controlled by mass transfer limitations caused by coke deposition. Two types of coke (extractable and non-extractable) were identified. Combining liquid phase reaction with continuous extraction of the catalyst with refluxing reaction mixture in a Soxhlet-like reactor led to a higher conversion of phenyl acetate in the Fries rearrangement. The ratio of protonated to acylated surface centres strongly determines the selectivity. The formation of o-hydroxyacetophenone proceeds both via intramolecular rearrangement and intermolecular acylation. On the other hand, p-hydroxyacetophenone is formed entirely by intermolecular acylation.

Friedel-Crafts Alkylation and Acylation in the Absence of Solvent

A short and efficient synthetic route, for alkylation and acylation of aromatic compounds in the absence of solvent is developed. According to the reaction system and conditions used, different alkyl-, and acyl arenes are obtained in moderate to good yields. The structures are assigned by 1H and 13C NMR spectroscopy.

ChemInform Abstract: Regioselectivity of Friedel‐Crafts Acylation of Aromatic Compounds with Several Cyclic Anhydrides.

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The First Unequivocal Evidence of the Reacting Electrophile in Aromatic Acylation Reactions1

The acylation of aromatic compounds with aroyl triflates can be performed in organic solvents (1,2-dichloroethane) without Friedel−Crafts catalysts. These reaction conditions allow kinetic investig...

ChemInform Abstract: Electrophilic Aromatic Substitution. Part 33. Ferric Chloride‐Catalyzed Acylation of Aromatic Compounds with N‐Phthaloyl‐α‐amino Acyl Chlorides Without Racemization.

AbstractAcylation of the arene (II) with the acid chlorides derived from (I) yields the ketones (III) without racemization.

ChemInform Abstract: Acylation of Aromatic Compounds in the Presence of Sulfodifluoro Acetic Acid.

AbstractSulfodifluoressigsäure (IIIa) oder ihr Methylester (IIIb) katalysieren die Acylierung der Aromaten (I) zu den Ketonen (IV).

Electrochemical acylation of aromatic compounds

Acylation of a range of aromatic compounds has been effected by the in situ generation of an energetic acylating species during the anodic oxidation at vitreous carbon of 2,3,5,6-tetramethoxyquinol diacetate in trifluoroacetic acid solution.

Catalytic Friedel‐Crafts Acylation of Aromatic Compounds

For the synthesis of aryl ketones from aromatic compounds and acid chlorides or anhydrides at least one equivalent of Friedel-Crafts catalyst is required. Highly activated arenes such as mesitylene or anisole may be acylated also with strong Bronsted acids, though in poor yields.

417. The reaction between aromatic compounds and derivatives of tertiary acids. Part IV. Preliminary kinetic data on the acylation of aromatic compounds by pivaloyl chloride

417. The reaction between aromatic compounds and derivatives of tertiary acids. Part IV. Preliminary kinetic data on the acylation of aromatic compounds by pivaloyl chloride

Hydrogen Fluoride as a Condensing Agent. VII.1 The Acylation of Aromatic Compounds

Hydrogen Fluoride as a Condensing Agent. VII.¹ The Acylation of Aromatic Compounds