2,2,6,6-Tetramethylpiperidinium triflate (TMPT): a highly selective and self-separated catalyst for esterification
作者:Lan Gao、Taoping Liu、Xiaochun Tao、Yongmin Huang
DOI:10.1016/j.tetlet.2016.09.061
日期:2016.11
An eco-friendly and readily accessible 2,2,6,6-tetramethylpiperidinium triflate was found as highly-selective and self-separated catalyst for esterification under solvent-free condition. The X-ray crystallography revealed that it formed a ‘hydrophobic wall’ which could effectively eliminate the generated water from the reactive sites. Moreover, it could precipitate from the reaction system with excellent
activity with the combined use of Hf(O-i-Pr)4 or Zr(O-i-Pr)4 and Fe(O-i-Pr)3 for direct esterification and a very simple method for their extraction with ionic liquids for their recovery and reuse are described. This Zr(IV)Fe(III) complex is an environmentally benign catalyst due to its high turnover number, extremely mild Lewis acidity, low toxicity, reusability, and commercial availability at low cost.
Iron(III)–Zirconium(IV) Combined Salt Immobilized onN-(Polystyrylbutyl)pyridinium Triflylimide as a Reusable Catalyst for a Dehydrative Esterification Reaction
is useful as a solid support to immobilize a zirconium(IV)–iron(III) binarymetalcomplex, which is a homogeneous catalyst for the dehydrative ester condensation of an equimolar mixture of carboxylic acids and alcohols. The immobilized zirconium(IV)–iron(III) complex is easily recovered by filtration after complete esterification, and is reusable without any loss of activity.
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
Bulky Diarylammonium Arenesulfonates as Selective Esterification Catalysts
作者:Kazuaki Ishihara、Shoko Nakagawa、Akira Sakakura
DOI:10.1021/ja050223v
日期:2005.3.1
large-scale, fundamental reactions such as 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