Study on the separation of rac and meso isomers and the reactivity of group 4 bridged metallocene complexes

外消旋和内消旋异构体的分离及第4族桥联茂金属配合物的反应性研究

• 批准号: 11640544
• 负责人: YAMAZAKI Hiroshi
• 金额: $ 0.38万
• 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: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640544/
• 关键词: group 4 metallocene; polymerization catalyst; isotactic polypropylene; racisomer; meso isomer; separation; μ-oxo complex; 分離法; 4族メタロセン錯体

A C_2-symmetric group 4 bridged metallocene is known to be the excellent catalyst for isospeciic polymerization of propylene. However, the synthesis of the metallocene usually accompanies the formation of an achiral meso isomer which must be excluded before use because it catalyzes atactic polymerization. We found the convenient method to separate the meso isomer of silylenebis (trimethylcyclopentadienyl) zirconium dichloride (1) by selectively deriving it to the readily crystallizable μ-oxo complex. The method was also found to be applicable to the isomer separation of the related metallocenes. The μ-oxo complexes were readily converted to the original meso isomers and to an η^2-acetate complex by treating with hydrogen chloride and acetic acid, respectively. The reactions of meso isomer of 1 with methyllithium and phenylethynyllithium gave methyl and phenylethynyl derivatives and the corresponding μ-oxo complexes. The structures of μ-oxo complexes and η^2-acetate complexes were determined by X-ray crystallographic analysis. Attempts to convert meso isomer of 1 to the rac isomer were not successful.

已知C_2-对称基团4桥联茂金属是丙烯同种聚合的优异催化剂，然而，茂金属的合成通常伴随着非手性内消旋异构体的形成，该异构体在使用前必须排除，因为它催化无规聚合。找到了分离亚硅基双(三甲基环戊二烯基)二氯化锆内消旋异构体的便捷方法(1) 通过选择性地将其衍生为易于结晶的μ-氧配合物，该方法也适用于相关茂金属的异构体分离。μ-氧配合物很容易转化为原始内消旋异构体和η。分别用氯化氢和乙酸处理，1的内消旋异构体与甲基锂和苯乙炔基锂反应得到甲基。苯乙炔基衍生物和相应的μ-氧配合物通过X射线晶体学分析确定了μ-氧配合物和η^2-乙酸配合物的结构。将1的内消旋异构体转化为外消旋异构体的尝试没有成功。

项目成果

H.Yamazaki: "Novel High Performance ansa-Zirconocene Catalyets for IsospeciBic Polymerization of Propylene"Chem.Lett.,. No.12. 1311-1312 (1999)

H.Yamazaki：“用于丙烯同种聚合的新型高性能 ansa-Zirconocene 催化剂”Chem.Lett.，。

M.Koyama: "Synthesis of μ-Qxo Complexes of Group4 Bridged Metallocenes : a convenient separation of meso and racemo Isomers"Chem.Lett.,. No.11. 1139-1140 (1998)

M.Koyama：“第 4 族桥连茂金属的 μ-Qxo 配合物的合成：内消旋异构体的方便分离”Chem.Lett.，1139-1140（1998）。

M.Koyama, K.Kimura, M.Nakano, H.Yamazaki: "Synthesis of μ-Oxo Complexes of Group 4 Bridged-Metallocenes : A Convenient Separation of meso and racemo Isomers"Chem.Lett.. 1139-1140 (1998)

M.Koyama、K.Kimura、M.Nakano、H.Yamazaki：“第 4 族桥接金属茂的 μ-Oxo 配合物的合成：内消旋和外消旋异构体的方便分离”Chem.Lett.. 1139-1140 (1998)

H.Yamazaki: "Novel High Performance ansa-zirconocene Catalysts for Isospecific Polymerization of Propylene"Chem.Lett.,. No.12. 1311-1312 (1999)

H.Yamazaki：“用于丙烯等规聚合的新型高性能柄型锆茂催化剂”Chem.Lett.，。

H.Yamazaki, K.Kimura, M.Nakano, T.Ushioda: "Novel High Performance ansa-Zirconocene Catalysts for Isospecific Polymerization of Propylene"Chem.Lett.. 1311-1312 (1998)

H.Yamazaki、K.Kimura、M.Nakano、T.Ushioda：“用于丙烯等规聚合的新型高性能 ansa-Zirconocene 催化剂”Chem.Lett.. 1311-1312 (1998)