Nickel(II)-Catalyzed Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Alkylidene Malonates
作者:Jiangting Li、Xiangjin Lian、Xiaohua Liu、Lili Lin、Xiaoming Feng
DOI:10.1002/chem.201203891
日期:2013.4.15
reaction conditions. The reaction could be carried out on a gram scale with the good results being maintained. Control experiments were performed to elucidate the specific diastereoselectivity of the reaction. The formation of single trans isomers was dominated by secondary orbital interactions between the ester groups of the dipolarophile and the azomethine imine. On the basis of the experimental results
我们通过使用手性N,N'-二氧化物-Ni II络合物作为催化剂,证明了亚甲亚胺甜菜碱与亚烷基丙二酸酯的不对称1,3-偶极环加成反应。发现芳族和脂族取代的亚烷基丙二酸酯都适合该反应。在温和的反应条件下,仅以优异的收率(最高99%的收率)和良好的对映选择性(最高97%ee)获得了一系列反式吡唑啉酮衍生物 。该反应可以以克为单位进行,并保持良好的结果。进行对照实验以阐明反应的特定非对映选择性。单一的形成反式亲核异构体主要由双极性亲子基团与偶氮甲亚胺的亚胺之间的次级轨道相互作用所决定。根据实验结果和以前的报告,假定可能的催化模型。