On the Configurational Stability of Chiral, Nonracemic Fluoro- and Iodo-[D<sub>1</sub>]Methyllithiums
作者:Dagmar C. Kail、Petra Malova Krizkova、Anna Wieczorek、Friedrich Hammerschmidt
DOI:10.1002/chem.201304766
日期:2014.4.1
fluoro‐[D1]methyllithium and iodo‐[D1]methyllithiums of up to 92 % ee were generated by transmetalation of the corresponding stannanes with MeLi in THF at various temperatures. The intermediate halo‐[D1]methyllithiums were trapped with benzaldehyde or acetophenone already present in excess in the reaction mixture to either give halohydrins or to disintegrate to carbene. The fluoro‐[D1]methyllithiums were
对映体纯的氟代[D 1 ]甲基锂和碘代[D 1 ]甲基锂高达ee的92%, 是通过将相应的锡烷与MeLi在THF中在不同温度下进行金属转移而生成的。中间体卤代[D 1 ]甲基锂被反应混合物中已经过量存在的苯甲醛或苯乙酮捕集,得到卤代醇或分解成卡宾。发现氟[D 1 ]甲基锂在-95至0°C的测试范围内在微观上是构型稳定的,但由于分解成卡宾的部分迅速增加,因此仅在低于-95°C的温度下才化学稳定。碘[D 1在所有测试温度(-95至-30°C)下,相对于PhCHO的添加速率,]甲基锂的构型不稳定。卡宾的分解也受到干扰。