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.

本征手性环戊二烯配体的合成是本项目的重点。在这种情况下，本质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性催化剂中进行研究。例如，在合适的位置上进一步的环结构导致扩展的pi-体系，其中包含一个环戊二烯单元和一个螺烯类型的结构。这种配体具有轴向手性，轴在环戊二烯的一个C-C键上。从初步研究可知，这类配体的基本结构7H-二苯并[c，g]荧会在室温下迅速平衡。外消旋势垒增加的模拟配体在立体选择性催化方面将是很有兴趣的。通过增加配基主链中的空间位阻，它们将是可获得的。通过对文献的筛选，我们已经确定了通向这种配体的三种不同的可能途径。此外，文献中还描述了外消旋体的拆分的前体或类似体系。环戊二烯配合物对许多过渡金属的催化活性是众所周知的。据我们所知，还没有本征手性环戊二烯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