Asymmetric C–C bond formation via Darzens condensation and Michael addition using monosaccharide-based chiral crown ethers
作者:Péter Bakó、Zsolt Rapi、György Keglevich、Tamás Szabó、Péter L. Sóti、Tamás Vígh、Alajos Grűn、Tamás Holczbauer
DOI:10.1016/j.tetlet.2011.01.094
日期:2011.3
phase asymmetric Darzens condensations were promoted by d-glucose- and d-mannose-based crown ethers. The corresponding aromatic and heteroaromatic α,β-epoxyketones were obtained with moderate to high enantioselectivities (up to 96%) as well as diastereoselectivities (up to 98:2) under mild reaction conditions. The absolute configurations of several of the epoxyketones were determined by single crystal
d-葡萄糖和d-甘露糖基冠醚促进了液相-液相不对称Darzens缩合反应。在温和的反应条件下,获得了具有中等至高对映选择性(最高96%)以及非对映选择性(最高98:2)的相应芳族和杂芳族α,β-环氧酮。通过单晶X射线分析确定几种环氧酮的绝对构型。乙酰氨基丙二酸二乙酯在反式-β-硝基烯烃中的迈克尔加成反应是在固-液两相系统中,在以d-葡萄糖为基础的冠状催化剂存在下,ee高达99%。