either carboxylic acids or alcohols are normally needed. We found that the directcondensation of equimolar amounts of carboxylic acids and alcohols could be achieved using hafnium(IV) or zirconium(IV) salts. These metal salts are highly effective as catalysts for the selective esterification of primary alcohols with carboxylic acids in the presence of secondary alcohols or aromatic alcohols. The present
Esterification of free fatty acids (Biodiesel) using nano sulfated-titania as catalyst in solvent-free conditions
作者:Mona Hosseini-Sarvari、Esmat Sodagar
DOI:10.1016/j.crci.2012.10.016
日期:2013.3
Résumé Nano sulfated titania was tested as catalyst for esterification of free fatty acids, specially methanolic and ethanolic esterification of stearic acid (biodiesels). Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents on ester conversion. This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. This prepared sulfated titania showed high catalytic activity in direct esterification of fatty acids as well as benzoic acids with various alcohols and phenols under solvent-free conditions. This method is of great value because of its environmentally benign character, easy handling, high yields, convenient operation, and green. FT-IR studies are shown that the catalyst can be reused for acylation without loss of catalytic activity.
Esterification of sterically hindered acids and alcohols in fluorous media
作者:Badra Gacem、Gérard Jenner
DOI:10.1016/s0040-4039(02)02872-1
日期:2003.2
Sterically hindered esterification reactions are best performed in specific fluorous media in the presence of catalytic amounts of diphenylammonium triflate. Fluorous media, in addition to their positive effect on yields, have inherent favorable properties respecting environment and permitting simple work-up. Highly congested reagents, however, react only marginally.
Copper-Catalyzed Alkoxycarbonylation of Alkanes with Alcohols
作者:Yahui Li、Changsheng Wang、Fengxiang Zhu、Zechao Wang、Pierre H. Dixneuf、Xiao-Feng Wu
DOI:10.1002/cssc.201601587
日期:2017.4.10
Esters are important chemicals widely used in various areas, and alkoxycarbonylation represents one of the most powerful tools for their synthesis. In this communication, a new copper‐catalyzed carbonylative procedure for the synthesis of aliphatic esters from cycloalkanes and alcohols was developed. Through direct activation of the C −H bond of alkanes and with alcohols as the nucleophiles, the desired
Bulky diarylammonium arenesulfonates as mild and extremely active dehydrative ester condensation catalysts
作者:Akira Sakakura、Shoko Nakagawa、Kazuaki Ishihara
DOI:10.1016/j.tet.2005.09.059
日期:2006.1
especially large-scale, fundamental reactions like estercondensations, are highly desirable for many reactions. Bulky diarylammonium pentafluorobenzenesulfonates and tosylates serve as extremely active dehydration catalysts for the estercondensation reaction of carboxylicacids with equimolaramounts of sterically demanding alcohols and acid-sensitive alcohols. Typically, the esterification reaction is performed