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    王岩, 马海燕. 导向配体辅助选择性合成rac-C2H4-(η5-Ind)2ZrCl2[J]. 华东理工大学学报(自然科学版), 2012, (5): 529-536.
    引用本文: 王岩, 马海燕. 导向配体辅助选择性合成rac-C2H4-(η5-Ind)2ZrCl2[J]. 华东理工大学学报(自然科学版), 2012, (5): 529-536.
    WANG Yan, MA Hai-yan. Selective Synthesis of rac-C2H4-(η5-Ind)2ZrCl2 Assisted by Ancillary Directing Ligands[J]. Journal of East China University of Science and Technology, 2012, (5): 529-536.
    Citation: WANG Yan, MA Hai-yan. Selective Synthesis of rac-C2H4-(η5-Ind)2ZrCl2 Assisted by Ancillary Directing Ligands[J]. Journal of East China University of Science and Technology, 2012, (5): 529-536.

    导向配体辅助选择性合成rac-C2H4-(η5-Ind)2ZrCl2

    Selective Synthesis of rac-C2H4-(η5-Ind)2ZrCl2 Assisted by Ancillary Directing Ligands

    • 摘要: 利用一系列含O、S、N配位原子的导向型辅助配体,与四氯化锆发生配位反应,生成具有一定空间导向作用的中间体配合物,用于研究其与亚乙基桥联双茚二锂盐C2H4[(η5Ind)Li]2反应时对络合产物非对映选择性合成的诱导作用。结果表明所合成的大多数辅助配体均导向选择性生成呈C2对称的一对外消旋异构体racC2H4(η5Ind)2ZrCl2,产物中外消旋异构体racC2H4(η5Ind)2ZrCl2与内消旋异构体mesoC2H4(η5Ind)2ZrCl2的摩尔比最高达到74∶26。进一步的研究表明,导向辅助配体与四氯化锆所形成的中间体配合物的结构、导向辅助配体配位原子类型及其取代基都对后续的导向选择性合成产生重要影响。

       

      Abstract: A series of ancillary directing ligands bearing O, S, N atoms were used to react with ZrCl4 to get the intermediate complexes, which showed certain diastereoselectivity when reacting with the dilithium salts of ethenebridged bis(indene). To carry out the selective synthesis, the ancillary directing ligand was firstly reacted with equal molar amount of ZrCl4 in toluene under argon overnight. The resultant suspension was transferred to the solid salts of C2H4[(η5Ind)Li]2 (molar ratio 1∶1) at 0 ℃. The reaction mixture was warmed up and stirred for 48 h at 30 ℃. Then the solvent was removed under vacuum and the residue was analyzed directly by 1HNMR spectroscopy to detect the relative amount of racC2H4(η5Ind)2ZrCl2 and mesoC2H4(η5Ind)2ZrCl2. Most of these ancillary directing ligands assisted the formation of racemic isomers, racC2H4(η5Ind)2ZrCl2, with the molar ratio of racC2H4(η5Ind)2ZrCl2 to mesoC2H4(η5Ind)2ZrCl2 as high as 74∶26. Further research demonstrated that the diastereoselectivity was significantly influenced by the structure, coordination atoms and substituents thereon of the intermediate complexes.

       

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