49619-44-5Relevant articles and documents
Size-Driven Inversion of Selectivity in Esterification Reactions: Secondary Beat Primary Alcohols
Mayr, Stefanie,Marin-Luna, Marta,Zipse, Hendrik
, p. 3456 - 3489 (2021/03/01)
Relative rates for the Lewis base-mediated acylation of secondary and primary alcohols carrying large aromatic side chains with anhydrides differing in size and electronic structure have been measured. While primary alcohols react faster than secondary ones in transformations with monosubstituted benzoic anhydride derivatives, relative reactivities are inverted in reactions with sterically biased 1-naphthyl anhydrides. Further analysis of reaction rates shows that increasing substrate size leads to an actual acceleration of the acylation process, the effect being larger for secondary as compared to primary alcohols. Computational results indicate that acylation rates are guided by noncovalent interactions (NCIs) between the catalyst ring system and the DED substituents in the alcohol and anhydride reactants. Thereby stronger NCIs are formed for secondary alcohols than for primary alcohols.
Cu-MOF: An efficient heterogeneous catalyst for the synthesis of symmetric anhydrides: Via the C-H bond activation of aldehydes
Ahmadzadeh, Zahra,Mokhtari, Javad,Rouhani, Morteza
, p. 24203 - 24208 (2018/07/25)
In this paper, an efficient and straightforward synthetic approach for the preparation of a number of symmetric carboxylic anhydrides was reported using Cu2(BDC)2(DABCO) as an efficient heterogeneous catalyst via the C-H bond activation of aldehydes with excellent yields and simple work up. This C-H bond activation reaction appears simple and convenient, has a wide substrate scope and makes use of cheap, abundant, and easily available reagents. The Cu-MOF catalyst was recycled and reused four times without any loss of catalytic activity.
An investigation on practical synthesis of carboxylic acid derivatives using p-toluenesulfonyl chloride
Eskandari, Parvin,Kazemi, Foad
, p. 431 - 439 (2017/07/24)
Carboxylic acid derivatives are well recognized as important class of reagents frequently used in the preparation of a variety of fine or special chemicals such as amides, esters, peptides, drugs, and dyes. Although several methods were developed for the preparation of these compounds, many of them present difficulties, including low yield, high reaction temperature, harsh reaction conditions, tedious work-up, and incompatibility with scale-up. Methods: The synthesis of carboxylic anhydrides is developed through the reaction of carboxylic acids with TsCl in the presence of K2CO3 and acetonitrile as a solvent under ultrasound irradiation and conventional conditions. In addition, one-pot synthesis of acyl azides was carried out in the presence of produced carboxylic anhydrides and the addition of sodium azide under identical condition. Results: A series of carboxylic anhydrides and acyl azides were synthesized using TsCl under ultrasound irradiation and conventional stirring with simple procedure, mild reaction conditions, high yields, and scale-up ability without any restriction. In most cases, the reaction under ultrasound irradiation was better in both yields and the reaction times compared to the conventional method. Conclusion: A convenient method has been developed for the preparation of carboxylic anhydrides and acyl azides under ultrasound irradiation and conventional stirring. The present method is practical and a highly effective alternative for previous reports. The major advantages of this method are: (i) simplicity of the procedure (ii) high yields and high purity of product (iii) scale-up capacity without considerable limitation in conventional system. Under ultrasound irradiation short reaction times as compared to conventional method are observed; yields are comparable to or better than conventional method.
