Syntheses and Crystal Structures of Highly Diastereomerically Enriched Lithiated Benzylsilanes in the Presence of External Donor Molecules: Experiment and Theory
Syntheses and Crystal Structures of Highly Diastereomerically Enriched Lithiated Benzylsilanes in the Presence of External Donor Molecules: Experiment and Theory
复制标题
外部供体分子存在下高度非对映体富集的锂化苄基硅烷的合成和晶体结构：实验和理论
DOI：
10.1002/ejic.200300323
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发表时间：
2003
影响因子：
2.3
通讯作者：
Daniel Schildbach
中科院分区：
文献类型：
--
作者：
C. Strohmann;D. Buchold;Timo Seibel;K. Wild;Daniel Schildbach
锂化(氨甲基)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]的固态结构[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通过单晶X射线衍射方法测定。将 TMEDA 桥联二聚体 [(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（一种配位聚合物）的晶体结构进行了比较。通过计算方法[B3LYP/6−31+G(d)]，研究了起始化合物(氨甲基)苄基硅烷[(S)-1]的去质子化机制，以及(R,S)-2的锂化衍生物的构型稳定性。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构型的反转，并将其与量子化学研究的结果相关联。 (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 德国, 2003)
The 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 the TMEDA-bridged dimer [(R,S)-2]2·TMEDA and monomeric (R,S)-2·DABCO were compared to that of the parent compound (R,S)-2, a coordination polymer. By computational methods [B3LYP/6−31+G(d)], the mechanism of the deprotonation of the starting compound, (aminomethyl)benzylsilane [(S)-1], as well as the stability of configuration of the lithiated derivatives of (R,S)-2, were examined. For the highly diastereoselective substitution reactions of the derivatives of (R,S)-2 with iodomethane, inversion of the configuration at the metallated carbon centre was observed and correlated with the results of the quantum-chemical studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)