Thiourea catalysed reduction of α-keto substituted acrylate compounds using Hantzsch ester as a reducing agent in water
作者:Guanglin Weng、Xiaobo Ma、Dongmei Fang、Ping Tan、Lijiao Wang、Linlin Yang、Yuanyuan Zhang、Shan Qian、Zhouyu Wang
DOI:10.1039/c7ra00995j
日期:——
The first method for the reduction of α-keto substituted acrylate compounds by Hantzsch ester in water under the catalysis of thiourea has been developed. The products were isolated in moderate to high yields (38–95%). These products are important intermediates in the synthesis of a series of natural products and other biologically active molecules.
The reaction cascade consisting of deprotection/decarboxylation/asymmetric protonation of enolic species, starting from open-chain benzyl β-oxo esters, has been studied. When carried out in the presence of catalytic amounts of cinchonine, the reaction gave optically active α-aryl ketones with up to 75% ee. Enantio-enriched (S)-3-phenyl-2-butanone can be converted into 2-phenylpropionic acid without