Stereoselective Control of Planar α-Dimethylsulfonium Benzyl Carbanions. Synthesis of Optically Pure <i>trans</i>-Aziridines
作者:Yolanda Arroyo、Ángela Meana、J. Félix Rodríguez、M. Ascensión Sanz-Tejedor、Inés Alonso、José L. García Ruano
DOI:10.1021/jo900381b
日期:2009.6.5
(R)-N-Sulfinylimine and (S)-N-sulfinylimine react with the ylide derived from (S)-dimethyl-[2-(p-toluenesulfinyl)phenyl]sulfonium salt, affording trans-2,3-disubstituted aziridines. A complete trans selectivity in low facial diastereoselectivity is observed when the configuration at the sulfur atoms of the reagents is the same. Otherwise, when their configurations are different, the reaction evolved
(R)-N-亚磺酰亚胺和(S)-N-亚磺酰亚胺与衍生自(S)-二甲基-[2-(对甲苯亚磺酰基)苯基] ulf盐的叶立德反应,得到反式-2,3-二取代的氮丙啶。当试剂的硫原子处的构型相同时,可以观察到低的非对映选择性的完全反式选择性。否则,当它们的构型不同时,反应会随着面部总非对映选择性和顺/反式而发展。比率介于1 / 4.2和1/9之间。理论计算表明反应主要是通过平面自由碳负离子的演化而进行的。过渡态的相对稳定性预测反式/顺式比与实验结果非常吻合。