A short access to 3,5-disubstituted piperazinones based on the aza-Michael addition of α-amino esters to β-substituted nitroalkenes
作者:Takayuki Kudoh、Seiji Isoyama、Sachiko Kagimoto、Katsutoshi Kurihara、Akira Sakakura
DOI:10.1016/j.tetlet.2016.09.015
日期:2016.10
A simple procedure for the synthesis of chiral 3,5-disubstituted piperazinones is described. The aza-Michael addition of α-amino esters to β-substituted nitroalkenes in an organic/aqueous biphasic solvent system followed by reduction of a nitro group with zinc nanopowder in acidic media and intramolecular ester–amide exchange under heating conditions gives piperazinones in good overall yields. This
描述了合成手性3,5-二取代哌嗪酮的简单方法。在有机/水性双相溶剂体系中,将α-氨基酯的aza-Michael加成到β-取代的硝基烯烃上,然后在酸性介质中用锌纳米粉还原硝基,并在加热条件下进行分子内酯-酰胺交换,从而使哌嗪酮具有良好的整体性能产量。通过改变起始硝基烯烃和α-氨基酯的组合,这种新颖的三步法可提供短距离接触各种手性3,5-二取代哌嗪酮的方法。该方法可用于简明合成含哌嗪酮的天然产物6',6''-二溴溴顺式-3,4-二氢金刚烷胺B。