Isolation and Racemization Mechanism of Optically Active Benzylmethylphenyltelluronium Salts
作者:Toshio Shimizu、Ryuuya Sakurai、Yoko Azami、Kazunori Hirabayashi、Nobumasa Kamigata
DOI:10.1002/ejoc.201000893
日期:2010.12
iodide, and tetraphenylborate, were also obtained by anion-exchange reactions of the separated diastereomers. The optically active telluronium salts possessing counteranions with a high nucleophilicity, such as bromide and iodide, were found to racemize in solution. The racemization of the telluronium salts was found to proceed either through the formation of a tellurane by the nucleophilic addition
合成了非对映异构苄基甲基苯基碲 (1S)-(+)- 和 (1R)-(-)-樟脑-10-磺酸盐,并通过分级重结晶进行拆分。异构体的绝对构型通过 X 射线晶体学分析确定。通过分离的非对映体的阴离子交换反应,还获得了具有非手性抗衡阴离子的对映体纯碲盐,例如四氟硼酸盐、4-氯苯磺酸盐、溴化物、碘化物和四苯基硼酸盐。发现具有高亲核性抗衡阴离子的旋光碲盐,例如溴化物和碘化物,在溶液中外消旋化。