Insights into the diastereoselective control in the sulfa-Michael addition of thiols to nitroalkenes: stereoelectronic effect in the cyclic chelated transition state
作者:Jiandong Wang、Pingfan Li、Zhanhui Yang、Ning Chen、Jiaxi Xu
DOI:10.1016/j.tet.2015.11.030
日期:2016.1
two approximately 1,2-diaxial substituents due to stereoelectronic effect control. The stereoelectronic effect in the cyclic chelated transition state was probed and verified by tuning the steric bulkiness of the corresponding substituents. The reaction involving 1-nitrocyclohexene provided perfect support for the proposed diastereoselective control model. The current investigation provided not only
研究了磺胺-迈克尔加成硝基烯烃和硫醇锂后进行质子化的非对映选择性控制。首先将硫醇锂添加到硝基烯烃中,得到环状的锂螯合的硝酸盐。由于具有立体电子效应,通过螯合物控制的六元半椅过渡态带有两个大约1,2-双轴取代基,证明了随后的硝酸盐动力学质子化是立体化学决定因素。通过调节相应取代基的空间体积,探索并验证了在环状螯合过渡态下的立体电子效应。涉及1-硝基环己烯的反应为提出的非对映选择性控制模型提供了完美的支持。