Discovery and Development of Pyridine-bis(imine) and Related Catalysts for Olefin Polymerization and Oligomerization,Accounts of Chemical Research

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Discovery and Development of Pyridine-bis(imine) and Related Catalysts for Olefin Polymerization and Oligomerization
Accounts of Chemical Research ( IF 16.4 ) Pub Date : 2015-08-12 00:00:00 , DOI: 10.1021/acs.accounts.5b00252
Brooke L. Small ₁

Affiliation

For over 40 years following the polyolefin catalyst discoveries of Hogan and Banks (Phillips) and Ziegler (Max Planck Institute), chemists traversed the periodic table searching for new transition metal and lanthanide-based olefin polymerization systems. Remarkably, none of these “hits” employed iron, that is, until three groups independently reported iron catalysts for olefin polymerization in the late 1990’s. The history surrounding the discovery of these catalysts was only the beginning of their uniqueness, as the ensuing years have proven these systems remarkable in several regards. Of primary importance are the pyridine-bis(imine) ligands (herein referred to as PDI), which produced iron catalysts that are among the world’s most active for ethylene polymerization, demonstrated “staying power” despite over 15 years of ligand improvement efforts, and generated highly active polymerization systems with cobalt, chromium, and vanadium. Although many ligands have been employed in iron-catalyzed polymerization, the PDI family has thus far provided the most information about iron’s capabilities and tendencies. For example, iron systems tend to be highly selective for ethylene over higher olefins, making them strong candidates for producing highly crystalline polyethylene, or highly linear α-olefins. Iron PDI polymerizes propylene with 2,1-regiochemistry via a predominantly isotactic, chain end control mechanism. Because the first insertion proceeds via 1,2-regiochemistry, iron (and cobalt) PDI systems can be tailored to make highly linear dimers of α-olefins by “head-to-head” coupling, resulting from a switch in regiochemistry after the first insertion. Finally, PDI ligands, while not being surpassed in activity, have inspired the development of related ligand families and complexes, such as pendant donor diimines (PDD), which are also highly efficient at producing linear α-olefins.

中文翻译：

吡啶双（亚胺）及相关的烯烃聚合和低聚催化剂的发现与发展

在Hogan和Banks（Phillips）和Ziegler（马克斯·普朗克研究所）发现聚烯烃催化剂之后的40多年来，化学家们遍历了元素周期表，以寻找新的过渡金属和镧系元素为基础的烯烃聚合体系。值得注意的是，这些“命中物”均未使用铁，也就是说，直到1990年代后期三个小组独立报告了用于烯烃聚合的铁催化剂。这些催化剂发现的历史仅仅是其独特性的开始，因为随后的几年证明了这些系统在几个方面都非常出色。最重要的是吡啶-双（亚胺）配体（以下简称PDI），尽管在15年以上的配体改进工作中，吡啶-双（亚胺）配体生产的催化剂在世界上对乙烯聚合反应最为活跃，但仍显示出“保持力”，并生成了具有钴，铬和钒的高活性聚合体系。尽管许多配体已用于铁催化的聚合反应中，但迄今为止，PDI系列已提供了有关铁的能力和趋势的最多信息。例如，铁系统倾向于对乙烯具有比高级烯烃更高的选择性，使其成为生产高结晶度聚乙烯或高线性α-烯烃的强候选者。铁PDI通过主要是全同立构的链端控制机理，通过2,1-区域化学作用聚合丙烯。由于第一次插入是通过1,2-区域化学进行的，因此铁（和钴）PDI系统可以进行定制，以通过“头对头”偶联制备α-烯烃的高度线性二聚体，这是由于第一次之后的区域化学转换所致插入。最后，PDI配体

更新日期：2015-08-12

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