Michael Addition Reactions between Chiral Ni(II) Complex of Glycine and 3-(<i>trans</i>-Enoyl)oxazolidin-2-ones. A Case of Electron Donor−Acceptor Attractive Interaction-Controlled Face Diastereoselectivity<sup>1</sup>
作者:Chaozhong Cai、Vadim A. Soloshonok、Victor J. Hruby
DOI:10.1021/jo0014865
日期:2001.2.1
noyl)oxazolidin-2-ones was found to depend exclusively on the steric bulk of the alkyl group on the starting Michael acceptor. In contrast, the face diastereoselectivity in the reactions of aromatic oxazolidin-2-ones with the Ni(II) complex of glycine was shown to be controlled predominantly by the electronic properties of the aryl ring. In particular, the additions of the Ni(II) complex of glycine
这项研究表明,具有高亲电性和构象均一性的,容易获得且便宜的3-(反式3'-烷基/芳基丙烯酰基)恶唑烷-2-酮是合成的迈克尔受体,优于常规使用的烷基烯醇酸酯,因此与甘氨酸的手性席夫碱的Ni(II)配合物与(S)-o- [N-(N-(苄基脯氨酰基)氨基]二苯甲酮的加成反应的反应活性和大多数情况下的非对映选择性显着提高。系统地研究了甘氨酸的Ni(II)配合物和恶唑烷-2-酮之间相应的迈克尔加成反应中的动力学控制的非对映选择性,它是取代基对起始迈克尔受体的空间,电子和位置效应的函数。在脂族和芳族系列中,发现简单的非对映选择性实际上都是完整的,从而通过相应的TS生成了具有类似进场几何形状的产物。发现甘氨酸的Ni(II)配合物与3-(反式3'-烷基丙烯酰基)恶唑烷丁-2-酮之间的反应的表面非对映选择性仅取决于起始迈克尔受体上烷基的空间体积。相反,芳族恶唑烷-2-酮与甘氨酸的Ni(II)配合物的反应中的