New Chiral Alignment Media based on Helically Chiral Synthetic Polymers and Graphene Oxides and Applications to Stereochemistry Elucidation

基于螺旋手性合成聚合物和氧化石墨烯的新型手性取向介质及其在立体化学阐明中的应用

• 批准号: 318391918
• 负责人: Professor Dr. Michael Reggelin
• 金额: --
• 依托单位: Arbeitsgruppe Organische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/318391918?language=en
• 关键词: New; Chiral; Alignment; Media; based

For many decades, the NMR-spectroscopic determination of the configuration and conformation of compounds in general and chiral compounds in particular was dominated by the evaluation of J-couplings and NOEs. At the end of the 90s, anisotropic NMR-parameters such as residual dipolar couplings (RDCs) started to being applied for struc-ture elucidation of biomolecules[1] and were later adopted in organic structure determination. RDCs are very powerful global parameters because they contain angular and distance information without the need for parametrization. How-ever, for their measurement an anisotropic environment preventing the analyte from tumbling isotropically, is neces-sary. This can be achieved either by stretched polymer gels or by lyotropic liquid crystalline (LLC) phases.[2] Some of these so called alignment media have been prepared in optically active form aiming at enantiomer differentiating orientation (sometimes called DOE: differential order effect) of chiral analytes to finally determine their absolute configuration. Preliminary studies around this topic have been conducted on three aspects in our groups: (i) develop-ment of graphene oxide liquid crystals as versatile and tunable alignment media in organic solvents (Conducted by Xinxiang Lei and Han Sun);[3] (ii) development of polyacetylenes and polyguanidines as enantiodifferentiating align-ment media (Conducted by Michael Reggelin);[4] (iii) methods development of absolute configurational determination in polyacetylene phases using MD simulations (Conducted by Han Sun and Michael Reggelin). The presented pro-posal will aim at transfering the strong enantiomer differentiating effect to other orienting systems and minimizing the amount of polymer needed per measurement (ca. 120 mg!) through a long-term established Sino-German research group. Both goals may possibly be attained by combining the favorable properties of graphene oxide with the ones offered by the polyarylacetylenes. To reach the final goal, the determination of absolute configurations, Han Sun will contribute with her expertise in modeling the polymer/analytes interactions.

几十年来，对一般化合物和特别是手性化合物的构型和构象的核磁共振波谱测定主要是通过评估 J 偶联和 NOE 来进行的。 20世纪90年代末，各向异性核磁共振参数如残余偶极耦合（RDC）开始应用于生物分子的结构解析[1]，后来被用于有机结构测定。 RDC 是非常强大的全局参数，因为它们包含角度和距离信息，而无需参数化。然而，为了进行测量，需要一个防止分析物各向同性翻滚的各向异性环境。这可以通过拉伸聚合物凝胶或溶致液晶 (LLC) 相来实现。[2]其中一些所谓的排列介质已以光学活性形式制备，旨在区分手性分析物的对映异构体方向（有时称为 DOE：微分级效应），以最终确定其绝对构型。围绕这一主题，我们课题组在三个方面进行了初步研究：（i）开发氧化石墨烯液晶作为有机溶剂中的多功能和可调配向介质（雷新祥和孙韩负责人）；（3）（ii）作为对映差异化配向介质的聚乙炔和聚胍的开发（Michael Reggelin负责人）；[4] (iii) 使用 MD 模拟确定聚乙炔相绝对构型的方法开发（由 Han Sun 和 Michael Reggelin 进行）。所提出的提案旨在通过长期建立的中德研究小组，将强大的对映体差异化效应转移到其他取向系统，并最大限度地减少每次测量所需的聚合物量（约120毫克！）。通过将氧化石墨烯的有利性能与聚芳基乙炔提供的性能相结合，可以实现这两个目标。为了实现最终目标，即确定绝对构型，Han Sun 将利用她在聚合物/分析物相互作用建模方面的专业知识做出贡献。