Preparation of New Metallocene Ligands with Combined Chiralities and Their Application to Catalytic Asymmetric Synthesis

（R，R）-1，2-双[（1-乙酰氧基）苯甲基]二茂铁与叠氮基三甲基硅烷在CH_2Cl_2中，在催化量的刘易斯酸如Cu（OTf）_2和Sc（OTf）_3存在下反应，得到主要产物（R，R）-异构体和少量的内消旋-（R，S）-异构体。用LiAlH_4还原二茂铁基二叠氮可将其转化为相应的二茂铁基二胺，并分离得到稳定的二甲苯磺酰胺和二乙酰胺。以二茂铁二胺和二茂铁二酰胺为配体，钌配合物催化芳基酮的不对称转移氢化反应，得到1-芳基乙醇，产率高达75%ee.平面手性邻恶唑啉取代甲酰基二茂铁与SmI_2发生频哪醇偶联反应，得到1，2-双二茂铁-1，2-二醇的三种非对映异构体的混合物，（R，R）：（S：S）：（R：S）=24：31：45.通过柱层析分离得到3种非对映体，并通过X-射线衍射分析证实了它们的立体化学结构。用s-BuLi还原Sm（OTf）_3制得的二价三氟甲磺酸钐Sm（OTf）_2，可显著提高（R，R）异构体的选择性，选择性可达50%。Yb（OTf）_3与（R，R）-二茂铁二醇的配合物对3-酰基恶唑烷酮与环戊二烯的不对称Diels-Alder反应具有良好的催化作用，生成的内加成物ee值高达80%。

The treatment of (R,R)-1,2-bis[(1-acetoxy)phenylmethyl]ferrocene with azidotrimethylsilane in CH_2Cl_2 in the presence of a catalytic amount of a Lewis acid such as Cu(OTf)_2 and Sc(OTf)_3, gave, the major (R,R)-isomer as major product with a minor meso-(R,S)-isomer. The optically active ferrocenyl diazide could be converted into the corresponding ferrocenyl diamine by reduction with LiAlH_4, and its ditosylamide and diacetamide were isolated as stable compounds. The ferrocenyl diamine and diamides were applied to ligands for the ruthenium complex catalyzed asymmetric transfer hydrogenation of aryl ketones and the complex with ferrocenyl diamine gave 1-arylethanols in good yields with up to 75% ee.The pinacol coupling reaction of planar chiral ortho-oxazoline substituted formylferrocene by SmI_2 gave a mixture of three diastereomers of 1,2-diferrocenyl-1,2-diols; (R,R):(S:S):(R:S)=24:31:45. The tree diastereomers could be isolated by column chromatography, and their stereochemistries were confirmed by X-ray diffraction analysis. The use of divalent samarium triflate "Sm(OTf)_2", which was prepared by reduction of Sm(OTf)_3 with s-BuLi, remarkably improved the selectivity for the (R,R) isomer with 50% de. The combination of Yb(OTf)_3 and the (R,R)-ferrocenyl diol was revealed to be a good catalyst for the asymmetric Diels-Alder reaction of 3-acyloxazolidinone with cyclopentadiene, and the endo adduct was produced in up to 80% ee.