Enantiopure Chiral (2,4,6-Triisopropylbenzoyl)oxy-[D<sub>1</sub>]methyllithium: Configurational Stability, Reactions, and Mechanistic Studies
作者:Dagmar C. Kapeller、Friedrich Hammerschmidt
DOI:10.1021/jo802625q
日期:2009.3.20
The configurationalstability of enantiopure chiral (2,4,6-triisopropylbenzoyl)oxy-[D1]methyllithium generated by a tin−lithium exchange was tested on the macroscopic time scale, employing trapping experiments with benzaldehyde. It was found to be configurationally stable for minutes at −78 °C and to be an appropriate substitute for the carbamoyloxy-substituted analogue in terms of cleavage. Its addition
在宏观时间尺度上测试了由锡-锂交换产生的对映纯手性(2,4,6-三异丙基苯甲酰基)氧基-[D 1 ] 甲基锂的构型稳定性,采用苯甲醛捕获实验。发现它在 -78 °C 下构型稳定数分钟,并且在裂解方面是氨基甲酰氧基取代类似物的合适替代品。研究了将其添加到几种亲电子试剂中,从而得出了制备手性伯氘化醇的方案,例如合成 2-苯基-[1-D 1]98% 对映体过量 (ee) 的乙醇。此外,通过标记底物的光谱研究解决了这种芳酰氧基甲基锂的对映异构化和分解机制。它通过形成乙烯(次要途径)和n- BuLi同系化最多三个亚甲基单元而分解,然后交换为 Bu 4 Sn的丁基。