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.

本项目的重点是合成具有内在手性的环己基双氧杂环己基配体。在本文中，固有手性的含义是手性元素是环戊二烯环的一部分。由这些配体衍生的过渡金属化合物将在立体选择性催化中进行研究。例如，芴在正确的位置上具有进一步的环结构，导致扩展的π-体系，其包含环戊二烯单元和螺烯型结构。这类配体具有轴向手性，轴在环己烯的C-C键之一上。从初步研究中我们知道，这种类型的配体的基本结构，7 H-二苯并[c，g]芴，将在室温下迅速平衡。具有增加的外消旋化屏障的手性配体对于立体选择性催化将是令人感兴趣的。它们将通过增加配体骨架中的空间位阻而可接近。通过筛选文献，我们已经确定了三种不同的可能途径导致这样的配体。此外，在文献中有前体或类似物系统，其中已经描述了外消旋体的拆分。环戊二烯配合物的催化活性是众所周知的许多过渡金属。迄今为止，还没有本征手性环戊二烯化合物用于立体选择性催化的实例。有了这个项目，我们将能够第一次阐明，这一战略是否会导致成功。

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