Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic deriva...Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic derivative of dimethyl malonate in high yields in solvent-free condition. 2009 Mohammad Reza Shushizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
N-Sulfonic acid poly(4-vinylpyridinum) hydrogen sulfate has been developed as a recyclable solid acid catalyst for the acetylation of alcohols, phenols, thiols, and amines, as well as the 1,1- diacetylation of aldehyd...N-Sulfonic acid poly(4-vinylpyridinum) hydrogen sulfate has been developed as a recyclable solid acid catalyst for the acetylation of alcohols, phenols, thiols, and amines, as well as the 1,1- diacetylation of aldehydes under solvent-free conditions at room temperature. The acetylated products were formed in good to excellent yields over short reaction times, and the catalyst could be readily recovered by filtration and used several times without any discernible loss in activity. The hydrogen sulfate anion of the catalytic system was found to play a critical role in enhancing the reaction time and yield of the acetylation reaction.展开更多
A facile and efficient synthesis of new 1,4-dihydropyridine derivatives was reported via Hantzsch three-com- ponent condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium ace...A facile and efficient synthesis of new 1,4-dihydropyridine derivatives was reported via Hantzsch three-com- ponent condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium acetate in the presence of a catalytic amount of triethylamine under solvent-free conditions. The method described here of- fers several advantages including high yields, short reaction times, and simple work-up procedure.展开更多
Esterification or transesterification reactions are usually carried out in the presence of homogeneous or heterogeneous catalysts. However, recently a new method was reported for the esterification of carboxylic acids...Esterification or transesterification reactions are usually carried out in the presence of homogeneous or heterogeneous catalysts. However, recently a new method was reported for the esterification of carboxylic acids by tributyl borate under solvent- and catalyst-free conditions. In order to show the synthetic ability of trialkyl borate esters in the esterification reactions, here, the esterification of other carboxylic acids and diacids by tributyl-, triisoamyl-, and tribenzyl borate under the same conditions were reported. Some of the prepared ester and diester products have found wide applications as plasticizers and synthetic ester base lubricants. The esterification reactions have been cleanly carried out in the absence of any solvent under catalyst-free conditions. The maximum rate belongs to isoamyl trichloroacetate （VIb） which reached about 76% within about 6.5 h. On the basis of obtained findings, it seems that electron withdrawing groups on carboxylic acid facilitate the esterification reaction.展开更多
基金Science and Research University for financial support of this work
文摘Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic derivative of dimethyl malonate in high yields in solvent-free condition. 2009 Mohammad Reza Shushizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘N-Sulfonic acid poly(4-vinylpyridinum) hydrogen sulfate has been developed as a recyclable solid acid catalyst for the acetylation of alcohols, phenols, thiols, and amines, as well as the 1,1- diacetylation of aldehydes under solvent-free conditions at room temperature. The acetylated products were formed in good to excellent yields over short reaction times, and the catalyst could be readily recovered by filtration and used several times without any discernible loss in activity. The hydrogen sulfate anion of the catalytic system was found to play a critical role in enhancing the reaction time and yield of the acetylation reaction.
文摘A facile and efficient synthesis of new 1,4-dihydropyridine derivatives was reported via Hantzsch three-com- ponent condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium acetate in the presence of a catalytic amount of triethylamine under solvent-free conditions. The method described here of- fers several advantages including high yields, short reaction times, and simple work-up procedure.
文摘Esterification or transesterification reactions are usually carried out in the presence of homogeneous or heterogeneous catalysts. However, recently a new method was reported for the esterification of carboxylic acids by tributyl borate under solvent- and catalyst-free conditions. In order to show the synthetic ability of trialkyl borate esters in the esterification reactions, here, the esterification of other carboxylic acids and diacids by tributyl-, triisoamyl-, and tribenzyl borate under the same conditions were reported. Some of the prepared ester and diester products have found wide applications as plasticizers and synthetic ester base lubricants. The esterification reactions have been cleanly carried out in the absence of any solvent under catalyst-free conditions. The maximum rate belongs to isoamyl trichloroacetate （VIb） which reached about 76% within about 6.5 h. On the basis of obtained findings, it seems that electron withdrawing groups on carboxylic acid facilitate the esterification reaction.
