Stereoselective synthesis of dehydroamino acids using malonic acid half oxyester and aromatic aldehydes
作者:Yuttapong Singjunla、Silvia Colombano、Jérôme Baudoux、Jacques Rouden
DOI:10.1016/j.tet.2016.03.043
日期:2016.5
Amido-substituted Malonic Acid Half Oxyesters (MAHOs) have proven to be excellent partners of various aromatic aldehydes in the presence of secondary amine, trifluoromethanesulfonic acid to perform a Knoevenagel–Doebner condensation under mild conditions with good to excellent yields. A mechanistic study revealed that the sequence involved the formation of an iminium intermediate to provide stereoselectively Z-α,β-unsaturated
开发了一种有效且直接的方法来合成具有多种底物的α,β-脱氢氨基酸衍生物。事实证明,在仲胺,三氟甲磺酸存在下,酰胺基取代的丙二酸半含氧酸酯(MAHOs)是各种芳族醛的极好伙伴,可在温和的条件下以良好或极好的收率进行Knoevenagel–Doebner缩合反应。机理研究表明,该序列涉及形成亚胺基中间体以提供立体选择性的Z -α,β-不饱和氨基酸。