On the Preparation and Determination of Configurational Stability of Chiral Thio- and Bromo[D<sub>1</sub>]methyllithiums
作者:Anna Wieczorek、Friedrich Hammerschmidt
DOI:10.1021/jo301441g
日期:2012.11.16
Thio- and bromo[D1]methyllithiums (ee 99%) were generated from the respective stannanes by tin–lithium exchange at temperatures ranging from 0 to −95 °C. Thio[D1]methyllithiums 6 were found to be microscopically configurationally labile on the time scale of the thiophosphate-α-mercaptophosphonate rearrangement even at −95 °C. Thio[D1]methyllithiums 13a and 13b underwent a thia-[2,3]-Wittig rearrangement
硫代和溴代 [D 1 ] 甲基锂(ee 99%)是通过锡-锂交换在 0 到 -95 °C 的温度下从各自的锡烷中生成的。发现硫代[D 1 ] 甲基锂6在硫代磷酸盐-α-巯基膦酸盐重排的时间尺度上即使在-95°C 下在微观上也不稳定。Thio[D 1 ] 甲基锂13a和13b经历了低至 -95 °C 的 thia-[2,3]-Wittig 重排,而13b仅低至 -50 °C。前者在-95°C以下微观构型稳定,后者在-50°C下完全消旋。手性溴[D 1] 甲基锂在 -78 °C 时化学性质不稳定,但在其加入苯甲醛和苯乙酮的时间尺度上在微观结构上是稳定的。