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

新型组合手性茂金属配体的制备及其在催化不对称合成中的应用

基本信息

批准号：
16550044
负责人：
FUKUZAWA Shin-ichi
金额：
$ 2.37万
依托单位：
Chuo University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

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.

在CuOTf_2和Sc(OTf)_3催化下，(R，R)-1，2-双[(1-乙酰氧基)苯甲基]二茂铁在CH2Cl2中与叠氮三甲基硅烷反应，得到主要产物为(R，R)-主要异构体和少量的中-(R，S)-异构体。光学活性的二茂铁基二叠氮化物可被LiAlH4还原为相应的二茂铁二胺，其二甲基酰胺和二乙酰胺为稳定的化合物。以二茂铁二胺和二酰胺为配体催化芳基酮的不对称转移加氢反应生成1-芳基乙醇，产率高达75%。平面手性邻恶唑啉取代甲酰基二茂铁与SnI_2的片呐醇偶联反应得到3种非对映异构体1，2-二茂铁基-1，2-二醇的混合物；(R，R)：(S：S)：(R：S)=24：31：45。用柱层析法分离得到树状非对映异构体，用X-射线衍射法确定了它们的立体化学结构。用S-BuLi还原Sm(OTf)_3制备的二价三氟化钐“Sm(OTf)_2”显著提高了对De含量为50%的(R，R)异构体的选择性。Yb(OTf)_3和(R，R)-二茂铁基二醇的组合对3-酰氧唑烷酮与环戊二烯的不对称Diels-Alder反应具有很好的催化作用，并且在高达80%ee的条件下生成内加合物。