Multisubstituted <i>C</i><sub>2</sub>-symmetric <i>ansa</i>-metallocenes bearing nitrogen heterocycles: influence of substituents on catalytic properties in propylene polymerization at higher temperatures
作者:Pavel S. Kulyabin、Vyatcheslav V. Izmer、Georgy P. Goryunov、Mikhail I. Sharikov、Dmitry S. Kononovich、Dmitry V. Uborsky、Jo Ann M. Canich、Alexander Z. Voskoboynikov
DOI:10.1039/d1dt00645b
日期:——
2′-dibromobiaryls with 4-aminoindenes, which were synthesized via Buchwald–Hartwig reaction or electrophilic amination of 4-indenyl Grignard reagents with trimethylsilylmethyl azide. By a number of examples, the anion-promoted rac-to-meso isomerization method was shown to work reliably well for preparation of rac-ZrMe2-complexes. Certain zirconocenes among the 21 tested in propylene polymerization at
在这项工作中,我们系统地研究了取代基修饰对基于异特异锆茂催化剂的Me 2 Si(2-Alk-4-(N -carbazolyl)Ind)ZrX 2(X = Cl,Me)性能的影响。 ,其中前体被证明特别适用于高温丙烯聚合工艺。为了获得所需的锆茂,我们开发了一种新的合成途径,即通过Pd催化2,2'-二溴联芳基与4-氨基茚的环化反应,生成4-(N-咔唑基)茚,这是通过Buchwald-Hartwig反应或亲电法合成的用三甲基甲硅烷基甲基叠氮化物将4-茚基格氏试剂胺化。通过许多例子,阴离子促进了外消旋-到-内消旋异构化方法被证明工作良好可靠制备的外消旋-ZrMe 2个-complexes。在MAO或硼酸盐活化下于70和100°C的丙烯聚合中测试的21种茂金属中,某些锆茂在分子量能力,区域选择性或立体选择性方面优于母体催化剂。