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Control of Stereoselectivity in Heterogeneous Catalysis by Functionalization of Pt Nanoparticles with Proline and Proline-derivatives

通过用脯氨酸和脯氨酸衍生物功能化 Pt 纳米颗粒来控制多相催化中的立体选择性

基本信息

批准号：
289757887
负责人：
Professor Dr. Marcus Bäumer, since 9/2018
金额：
--
依托单位：
Institut für Angewandte und Physikalische 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 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/289757887?language=en
关键词：
Control Stereoselectivity Heterogeneous Catalysis Functionalization

项目摘要

Chiral compounds in their enantiomeric pure form are of great importance e.g. as pharmaceutical ingredients. The demand for enantiomeric pure substances is continuously growing and as a result the need for sustainable preparation routes. Due to its ability to address this issue asymmetric catalysis is one of the most important research fields in chemistry and of great ecologic and economic relevance. It is a well-established topic in bio and metal-organic catalysis research. However, besides some few approaches asymmetric catalysis still remains a fundamental challenge for heterogeneous catalysis that requires new conceptional ideas and knowledge from basic research. Recently, the applicant demonstrated a proof of concept for a novel approach within the field of asymmetric, heterogeneous catalysis. Colloidal nanoparticles Pt were functionalized with hydrophilic ligands by coordinative or covalent binding, then supported and applied as heterogeneous catalysts. The potential of this concept was demonstrated and stereoselectivties were obtained already in the first investigations. So far, only little is known about what determines the catalytic properties of these materials. This is however prerequisite for developing novel stereoselective, active and stable catalysts based on ligand-functionalized nanoparticles. Recently, we were able to show that by functionalizing Pt nanoparticles with amine ligands the activity can be enhanced beyond the limit of ligand-free particles. Furthermore, the use of proline as ligands enabled us for achieving an enantiomeric excess of 34 % for the hydrogenation of a beta-ketoester (ethylacetoacetate). Based on these promising results the aim of the proposed project is to study the hydrogenation of beta-ketoesters over Pt nanoparticles functionalized with proline and proline derivatives. In order to tackle this challenge in a systematic manner we established a synthesis strategy that enables for the independent control of all catalytically relevant material properties (particle, ligand, and support). The influence of each of these as well as the reaction parameters on the stereoselectivity, activity, and stability shall now be investigated systematically. As ligand-functionalized nanoparticles exhibit characteristics of homogeneous metalorganic (ligand) as well as heterogeneous catalysts (particle, support) the guidelines for the studies are based on established knowledge of both fields. Thereby not merely the influence of the material characteristics on the catalytic properties will be investigated but furthermore to what extend concepts of the two catalysis areas are applicable to support ligand-functionalized nanoparticles.

对映体纯形式的手性化合物例如作为药物成分是非常重要的。对对映体纯物质的需求不断增长，因此需要可持续的制备路线。由于不对称催化能够解决这一问题，因此它是化学中最重要的研究领域之一，具有很大的生态和经济意义。它是生物和金属有机催化研究中的一个公认的主题。然而，除了一些方法，不对称催化仍然是一个根本的挑战，多相催化，需要新的概念和知识的基础研究。最近，申请人证明了在不对称多相催化领域内的新方法的概念证明。通过配位或共价键合的方式将亲水性配体功能化后的纳米Pt负载到纳米Pt上，并作为非均相催化剂应用。这一概念的潜力得到了证明，立体选择性已经在第一次调查。到目前为止，人们对这些材料的催化性能的决定因素知之甚少。然而，这是开发基于配体官能化纳米颗粒的新型立体选择性、活性和稳定催化剂的先决条件。最近，我们能够表明，通过用胺配体官能化Pt纳米颗粒，可以提高活性，超过无配体颗粒的极限。此外，使用脯氨酸作为配体使我们能够实现β-酮酯（乙酰乙酸乙酯）氢化的对映体过量34%。基于这些有希望的结果，所提出的项目的目的是研究在用脯氨酸和脯氨酸衍生物官能化的Pt纳米颗粒上的β-酮酯的氢化。为了以系统的方式应对这一挑战，我们建立了一种合成策略，该策略能够独立控制所有催化相关的材料特性（颗粒，配体和载体）。现在将系统地研究这些中的每一个以及反应参数对立体选择性、活性和稳定性的影响。由于配体功能化的纳米颗粒表现出均相金属有机物（配体）以及非均相催化剂（颗粒，载体）的特性，因此研究的指导方针是基于这两个领域的既定知识。因此，不仅将研究材料特性对催化性能的影响，而且还将研究两个催化领域的概念在多大程度上适用于支持配体官能化的纳米颗粒。