Acidic ionic liquid [NMP]H2PO4 as dual solvent-catalyst for synthesis of β-alkoxyketones by the oxa-Michael addition reactions
作者:Hui Guo、Xia Li、Jun-Liang Wang、Xiao-Han Jin、Xian-Fu Lin
DOI:10.1016/j.tet.2010.08.017
日期:2010.10
Acidic ionic liquid N-methyl-2-pyrrolidonium dihydrogen phosphate [NMP]H2PO4 was prepared and used as efficient catalyst and reaction medium to synthesize beta-alkoxyketones by the oxa-Michael addition reactions for the first time. The effect of anions and cations, amount of ionic liquid on the reaction was investigated. Various alcohols and phenols proceeded smoothly and led to corresponding beta-alkoxyketones with high yields under mild reaction conditions, O-selectivity addition of amino-ethanols was also achieved in this paper. Compared with traditional imidazolium ionic liquids, [NMP] H2PO4 gave the better results. The ionic liquid was stable and could be reused at least five times with a slight loss of activity. (C) 2010 Published by Elsevier Ltd.