A Convergent Method for the Synthesis of Highly Enantiomerically Enriched Cyclic Silanes with Silicon-Centered Chirality
A Convergent Method for the Synthesis of Highly Enantiomerically Enriched Cyclic Silanes with Silicon-Centered Chirality
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DOI：
10.1002/chin.200411258
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发表时间：
2003-12
期刊：
影响因子：
--
通讯作者：
M. Oestereich;U. Schmid;G. Auer;M. Keller
中科院分区：
文献类型：
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作者：
M. Oestereich;U. Schmid;G. Auer;M. Keller
已经开发出一种制备简单的方法，该方法允许将含硅的碳环组装成非对映异构体的混合物，而硅是立体产生信息的唯一中心。在Barbier条件下，通过等摩尔二溴化二氯硅烷和手性修饰的二氯硅烷反应一步合成手性环硅烷，得到几个单官能化的1-硅烷-1，2，3，4-四氢萘和相应的菲衍生物。阐述了3-(2-溴芳基)丙基溴化物和二氯硅烷的简便大规模合成方法。这种高度收敛的方法依赖于新型的(-)-薄荷氧基取代的二氯硅烷，它们安装了用于后续光学拆分的手性助剂。这些对映体二氯硅烷是一种通用的、模块化的一步法合成具有硅手性的硅烷的有用的构建块，因为这种策略避免了文献中报道的线性序列。对1-苯基-1-西拉-1，2，3，4-四氢萘衍生物的光学分辨率进行了示例性优化，并通过X射线结晶学确定了绝对构型。手性助剂通过简单的还原进行立体特定取代，得到高对映体富集型硅烷(Er=98：2)，该硅烷通过在硅上的Walden反转证实是对映体特定氯化的。
A preparatively straightforward methodology has been developed which allows the assembly of silicon-containing carbocycles as mixtures of diastereomers with silicon as the sole center of stereogenic information. One-step construction of the chiral cyclic silanes is realized by reaction of equimolar amounts of a dibromide and a chirally modified dichlorosilane under Barbier conditions giving access to several monofunctionalized 1-sila-1,2,3,4-tetrahydronaphthalenes and a corresponding phenanthrene derivative. Facile large scale syntheses of 3-(2-bromoaryl)propyl bromides as well as dichlorosilanes have been elaborated. This highly convergent methodology relies on the novel (-)-menthyl-oxy-substituted dichlorosilanes, which have the chiral auxiliary for the subsequent optical resolution installed. These enantiopure dichlorosilanes are useful building blocks for a general and modular one-step approach to silanes with silicon-centered chirality since this strategy avoids the linear sequences reported in literature. The optical resolution has been exemplarily optimized for the 1-phenyl-1-sila-1,2,3,4-tetrahydronaphthalene derivative and the absolute configuration has been established by X-ray crystallography. The chiral auxiliary is stereospecifically displaced by simple reduction providing the highly enantioenriched silane (er = 98:2) which is enantiospecifically chlorinated as verified by a Walden inversion at silicon.