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.

C2对称的4族桥联茂金属催化剂是丙烯等规聚合法的优良催化剂。然而，茂金属的合成通常伴随着非手性介孔异构体的形成，在使用之前必须排除它，因为它催化无规聚合。我们找到了一种简便的方法来分离二氯化硅双(三甲基环戊二烯)二氯化锆(1)的介晶异构体，方法是选择性地将其衍生为易结晶的μ-氧代络合物。该方法也适用于相关茂金属的异构体分离。分别用氯化氢和醋酸处理后，μ-氧代络合物很容易转化为原始的介晶异构体和η^2-醋酸酯络合物。1的介孔异构体与甲基锂和苯乙炔基锂反应，得到甲基和苯乙炔基衍生物以及相应的μ-氧代配合物。用X-射线单晶分析确定了μ-氧代配合物和η^2-乙酸酯配合物的结构。将1的介孔异构体转化为RAC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, 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)

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.，。