Synthesis of non-racemising twofold benzanullated fluorenide complexes and their application in stereoselective catalysis

非外消旋双苯并无效芴配合物的合成及其在立体选择性催化中的应用

• 批准号: 244035852
• 负责人: Professor Dr. Werner R. Thiel
• 金额: --
• 依托单位: Fachrichtung Anorganische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/244035852?language=en
• 关键词: Synthesis; non; racemising; twofold; benzanullated

The synthesis of intrinsically chiral cyclopentadiende ligands is in the focus of this project. In this context, the meaning of intrinsically chiral is that the element of chirality is part of the cyclopentadienide ring. Transition metal compounds derived from these ligands will be investigated in stereoselective catalysis.Anullation of e.g. fluorenide with further ring structures in the right position leads to extended pi-systems, which contain both, a cyclopentadienide unit and a helicene type structure. Such ligands are of axial chirality, the axis is on one of the C-C bonds of the cyclopentadienide. From preliminary investigations we know, that the basic structure of this type of ligands, the 7H-dibenzo[c,g]fluorene, will equilibrate rapidly at room temperature. Analogue ligands with an increased barrier of racemisation will be interesting for stereoselective catalysis. They will be accessible by increasing the steric hindrance in the ligand backbone. By screening the literature we have identified three different possible routes leading to such ligands. Furthermore there are precursors or analogue systems in the literature for which the resolution of the racemates have been described. Catalytic activity of cyclopentadienide complexes is well-known for many transition metals. As far vas we know, there is no example for an intrinsically chiral cyclopentadienide that was applied in stereoselectiv catalysis. With this project we will be able to elucidate for the first time, whether this strategy will lead to success.

本课题重点研究了固有手性环戊二烯配体的合成。在这种情况下，内在手性的含义是手性元素是环戊二烯环的一部分。从这些配体衍生的过渡金属化合物将在立体选择催化中进行研究。例如，对氟化物进行模拟，使其在正确位置上具有更多的环状结构，从而得到扩展的pi系统，其中既包含环戊二烯单元，又包含螺旋型结构。这种配体具有轴向手性，其轴位于环戊二烯的一个C-C键上。从初步的研究中我们知道，这类配体的基本结构，7h -二苯并[c，g]芴，在室温下会迅速平衡。具有增加外消旋势垒的类似配体对于立体选择性催化将是有趣的。它们可以通过增加配体主链中的位阻来接近。通过筛选文献，我们已经确定了三种不同的可能的途径导致这样的配体。此外，文献中还描述了外消旋体的分解的前体或类似体系。环戊二烯配合物的催化活性是众所周知的许多过渡金属。就我们所知，还没有一个固有手性环戊二烯被应用于立体选择性催化的例子。有了这个项目，我们将能够第一次阐明，这个策略是否会成功。

项目成果

Cyclopentadienide Ligand CpC– Possessing Intrinsic Helical Chirality and Its Ferrocene Analogues

具有固有螺旋手性的环戊二烯配体 CpCâ 及其二茂铁类似物

• DOI: 10.1021/acs.organomet.5b00673
• 发表时间: 2015
• 期刊: Organometallics
• 影响因子: 2.8
• 作者: J.-Y. Chung;C. Schulz;H. Bauer;Y. Sun;H. Sitzmann;H. Auerbach;A. J. Pierik;V. Schünemann;A. Neuba;W. R. Thiel
• 通讯作者: W. R. Thiel

Titanium(IV) complexes bearing the (Cp C ) − ligand

带有 (Cp C ) â 配体的钛 (IV) 配合物

• DOI: 10.1016/j.jorganchem.2016.10.035
• 发表时间: 2017
• 期刊: Journal of Organometallic Chemistry
• 影响因子: 2.3
• 作者: J.-Y. Chung;Y. Sun;W. R. Thiel
• 通讯作者: W. R. Thiel