Microwave-Assisted Acetylation of Alcohols Using Acidic Ethyl Acetate in Five Minutes

Fe3O4@SiO2/Schiff base complex of Co (II) nanocatalyst was used as a novel, efficient catalyst for acetylation of alcohols and phenols with acetic anhydride in high yields under solvent-free conditions. Various primary, secondary and tertiary alcohols were acetylated under solvent-free conditions in the presence of catalytic amount of the nanocatalyst at room temperature. Also, Fe3O4@SiO2/Schiff base/Co (II) can catalyze the acetylation of various alcohols by the reaction of alcohols with ethyl acetate under reflux conditions. The nanocatalyst can be simply recovered by a magnetic field and reused over 5 times without any significant loss of its catalytic activity.

Selective acetylation of primary alcohols by ethyl acetate

Fe3O4@SiO2/Schiff base complex of Co(II) nanocatalyst was used as a novel, efficient catalyst for acetylation of alcohols and phenols with acetic anhydride in high yields under solvent-free conditions. Various primary, secondary and tertiary alcohols were acetylated under solvent-free conditions in the presence of catalytic amount of the nanocatalyst at room temperature. Also, Fe3O4@SiO2/Schiff base/Co(II) can catalyze the acetylation of various alcohols by the reaction of alcohols with ethyl acetate under reflux conditions. The nanocatalyst can be simply recovered by a magnetic field and reused over five times without any significant loss of its catalytic activity.

A wide variety of alcohols were reacted with acetic anhydride at room temperature in the presence of a catalytic amount of N,N,N-trimethylanilinium tribromide to produce the corresponding alkyl acetates in good to excellent yields. Following this procedure, acetylation of primary, secondary, and tertiary alcohols has been performed under neutral conditions.

Preparation of sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester: A new and recyclable catalyst for the formylation and acetylation of alcohols under heterogeneous conditions

Microwaves in Organic Synthesis

Esters are demanded in a varied range of human industries and, although the classical methods for their production have been known since the late 19 th century, the search for improved and sustainable protocols to prepare this class of compounds is yet invaluable. An efficient, fast and straightforward method has been stablished, using TsOH and EtOAc for the acetylation of primary alcohols, with yields ranging from 81 to 98 %, depending on the groups near the hydroxyl group. A slight variation of the protocol might also be applied to secondary alcohols with moderate to high yields (65 to 91 %). Finally, the methodology can be used to selectively acetylate primary and secondary alcohols in the presence of tertiary or phenolic hydroxyl groups.

A variety of primary alcohols and phenols were reacted with acetic anhydride at room temperature in the presence of sodium bicarbonate to produce corresponding esters in good to excellent yields. The acetylation of 4-nitrobenzyl alcohol was also carried out using other bicarbonates and carbonates. The reaction in the presence of cesium bicarbonate and lithium carbonate gave 4-nitrobenzyl acetate in excellent yield, while in the presence of Na2CO3, K2CO3, Cs2CO3, or KHCO3 the yield was in the range of 80%–95%. Calcium carbonate and cobaltous carbonate did not promote the acetylation of 4-ntirobenzyl alcohol using acetic anhydride. The acetylation of 4-nitrobenzyl alcohol was carried out using ethyl acetate, THF, toluene, diethyl ether, dichloromethane and acetonitrile, and gave good yields ranging from 75%–99%. Toluene was the best solvent for the reaction, while diethyl ether was the poorest.

Highly efficient and selective acetylation of alcohols and phenols with acetic anhydride catalyzed by a high-valent tin(IV) porphyrin, Sn(TPP)(BF 4) 2

Investigation of catalytic activity of high-valent vanadium(IV) tetraphenylporphyrin: A new, highly efficient and reusable catalyst for acetylation of alcohols and phenols with acetic anhydride

Tribromo melamine as novel and versatile catalyst for the formylation and acetylation of alcohols

Highly efficient acetylation and benzoylation of alcohols, phenols, amines and thiols with acetic and benzoic anhydrides catalyzed by new and reusable zirconyl triflate, ZrO(OTf)2, is reported. The high catalytic activity of electron deficient ZrO(OTf)2 can be used for the acetylation and benzoylation of not only primary alcohols but also sterically-hindered secondary and tertiary alcohols with acetic and benzoic anhydrides. Acetylation of phenols with acetic and benzoic anhydrides was achieved to afford the desired acetates and benzoates efficiently. This catalyst also efficiently catalyzed the acetylation and benzoylation of amines and thiols whereby the corresponding amides and thioesters were obtained in good to excellent yields. This catalyst can be reused several times without loss of its activity.

Efficient esterification of primary and sterically-hindered secondary or tertiary alcohols with acetic anhydride was achieved in the presence of ammonium decatungestocerate(IV) icosahydrate, (NH4)8[CeW10O36]·20H2O, as catalyst in high yields. Primary and secondary alcohols were also converted to their corresponding acetates and formates with acetic acid and ethyl formate in the presence of this catalyst. Easy work-up, non-toxicity, reusability, and stability of the catalyst are noteworthy advantages of this method.

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Modified attapulgite: An efficient solid acid catalyst for acetylation of alcohols using acetic acid