Ch24 - Acylation of phenols - Faculty of Science
O-acylation: acylating agent (acyl chloride or anhydride) The product of C-acylation is more stable and predominates under conditions of thermodynamic control (i.e. when AlCl 3 is present). The product of O-acylation forms faster and predominates under conditions of kinetic control
Friedel–Crafts reaction of phenol - Chemistry Stack Exchange
2016年5月24日 · Phenol can react via two pathways with acyl chlorides to give either esters, via O -acylation, or hydroxyarylketones, via C -acylation. However, phenol esters also undergo a Fries rearrangement under Friedel-Crafts conditions to produce the C -alkylated, hydroxyarylketones.
Comparisons of O-acylation and Friedel–Crafts acylation of …
2011年1月21日 · In this paper, we report the comparisons of O- and C-acylation for the phenol reaction with acyl halides, and Fries rearrangement of phenyl ester using TfOH. Furthermore, the established conditions were applied to effective synthesis of optically pure hTyr using stoichiometric amounts of unprotected phenol and acyl chloride derivative of Asp.
Acylation of phenols to phenolic esters with organic salts
Selective O-acylation of phenolic compounds to produce phenolic esters which possess diverse applications is very attractive. Herein, we report an efficient, convenient one-pot method for selective O-acylation of phenols at room temperature in air. For the first time, abundant, safe, stable organic salts are used as acylating reagents.
In order to improve this method, we developed the new modification of the Schotten-Bauman techniques for preparing phenolic esters using equimolecular amounts of phenol and various alkanoyl chlorides in the presence of aqueous sodium hydroxide solution and a phase transfer catalyst (PTC) under biphasic conditions.6 Thus far, although it has been...
O-Acylation of Substituted Phenols with Various Alkanoyl …
2011年11月11日 · Esterification of several types of mono- and disubstituted phenols with various mono- and dialkanoyl chlorides was performed in phase-transfer catalysis conditions, using tetrabutylammonium chloride in a mixture of aqueous NaOH and dichloromethane.
Efficient O‐Acylation of Alcohols and Phenol Using Cp2TiCl as a ...
2016年7月4日 · In this paper, we report our recent results on the first transesterification and O-acylation of alcohols mediated by Cp 2 TiCl in the presence of CH 2 I 2 and an ester or an acyl chloride. This method gives esters from primary, secondary, and tertiary alcohols, and from phenol, under mild conditions at room temperature.
Acylation of phenol with acetic acid. Effect of density and …
1997年1月1日 · Whatever the sample phenol undergoes two main reactions: O-acylation into phenylacetate and C-acylation selectively into ortho-hydroxyacetophenone. While the rate of metaxylene isomerization depends only on the acidity of the MFI samples (density and strength of the acid sites) the rate of ortho-hydroxyacetophenone production is also determined ...
Regioselective direct ortho C-acylation of phenol and naphthol ...
In this research, we examined the ortho-acylation of phenol and naphthol compounds with organic acids as acylating agents catalyzed by alumina supported-Lewis acid as a new catalyst under microwave irradiation and atmospheric pressure conditions.
Acetylation of Alcohols, Amines, Phenols, Thiols under Catalyst …
2019年7月10日 · In the present study, an easy and an efficient approach is reported for the acetylation of alcohols, amines, phenols, and thiols under solvent- and catalyst-free conditions. The experimental conditions were milder than conventional methods and the reactions were completed in shorter reaction time.
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