Syntheses and Crystal Structures of Highly Diastereomerically Enriched Lithiated Benzylsilanes in the Presence of External Donor Molecules: Experiment and Theory
作者:Carsten Strohmann、Daniel H. M. Buchold、Timo Seibel、Kerstin Wild、Daniel Schildbach
DOI:10.1002/ejic.200300323
日期:2003.9
solid-state structures of the lithiated (aminomethyl)benzylsilanes Me2Si[(R)-(CHPhLi·0.5TMEDA)](CH2SMP) [(R,S)-2}2·TMEDA] and Me2Si[(R)-(CHPhLi·DABCO)](CH2SMP) [(R,S)-2·DABCO] [CH2SMP = (S)-2-(methoxymethyl)pyrrolidinomethyl] and the absolute configurations at the stereogenic metallated carbon centres of these compounds were determined by single-crystal X-ray diffraction methods. The crystal structures of
锂化(氨基甲基)苄基硅烷 Me2Si[(R)-(CHPhLi·0.5TMEDA)](CH2SMP)[(R,S)-2}2·TMEDA] 和 Me2Si[(R)-( CHPhLi·DABCO)](CH2SMP)[(R,S)-2·DABCO][CH2SMP = (S)-2-(甲氧基甲基)吡咯烷甲基]和这些化合物的立体金属化碳中心的绝对构型由单-晶体X射线衍射方法。将 TMEDA 桥连二聚体 [(R,S)-2]2·TMEDA 和单体 (R,S)-2·DABCO 的晶体结构与母体化合物 (R,S)-2 的晶体结构进行比较,聚合物。通过计算方法 [B3LYP/6−31+G(d)],起始化合物(氨基甲基)苄基硅烷 [(S)-1] 的去质子化机制,以及锂化衍生物的构型稳定性(R,S)-2,进行了检查。对于 (R,S)-2 衍生物与碘甲烷的高度非对映选择性取代反应,观察到金属化碳中心的构型反转,并与量子化学研究的结果相关联。(©