Copper and rhodium catalyzed dynamic kinetic asymmetric transformations

不对称合成催化方法的发展是化学领域最重要的成就之一。不对称催化是高效开发新药、香料、聚合物、材料和催化剂的关键技术。虽然存在许多广泛有用的催化不对称氧化和还原方法，但用于形成碳-碳键的不对称方法要少得多，碳-碳键是有机分子的骨架。通常在不对称催化中，使用前手性(通常是平坦的)起始原料，催化剂选择起始原料的一侧进行反应，该反应引入手性并选择性地产生产物的一个对映体。其中‘对映体’是特定的3D取向，通常被描述为一只‘手’，其中有两只可能的手，并且手或对映体是彼此的非重叠镜像。该项目旨在开发新的不对称反应，即外消旋起始物质(两个对映体或手性的50：50混合物)选择性地转化为产品的一个对映体，同时形成新的碳-碳键。与使用前手性起始材料相比，这是一个不那么直接的过程，而且只有极少数类型的反应可以使用这一策略。然而，由于有比前手性分子多得多的外消旋分子，使用外消旋起始物质的方法在不对称合成中将是非常有用的。使用外消旋起始材料的催化不对称碳-碳键的形成方法是已知的，但这些方法仅限于贵金属催化剂(钯、铱等)的组合。和一个特别稳定的反应伙伴。在这里，我们将开发不需要稳定反应伙伴的新方法。我们将使用核磁共振波谱来研究新的反应，并试图了解正在发生的化学途径。我们期望来自光谱研究的信息将对设计更多的反应非常有用。总体而言，这些研究将为快速合成具有广泛用途的各种分子提供重要的新方法。

The development of catalytic methods for asymmetric synthesis is one of the foremost achievements in chemistry. Asymmetric catalysis is a key technology in the efficient development of new medicines, fragrances, polymers, materials and catalysts. While many broadly useful methods for catalytic asymmetric oxidation and reduction exist, there are far fewer asymmetric methods for forming carbon-carbon bonds, which make up the framework of organic molecules. Typically in asymmetric catalysis, prochiral (usually flat) starting materials are used and the catalyst selects one side of the starting material for a reaction that introduces chirality and selectively produces one enantiomer of product. Where an 'enantiomer' is a specific 3d orientation, often described as one "hand" where there are two possible hands, and the hands or enantiomers are non-superimposible mirror images of each other. This project aims to develop new asymmetric reactions where racemic starting material (a 50:50 mixture of two enantiomers, or 'hands') is converted selectively into one enantiomer of a product at the same time that a new carbon-carbon bond forms. This is a much less straightforward process than using prochiral starting materials and there are only very few types of reaction that can use this strategy. However, as there are many more racemic than prochiral molecules, methods that use racemic starting materials would be very useful in asymmetric synthesis. Catalytic asymmetric carbon-carbon bond forming methods that use racemic starting materials are known, but these are limited to the combination of a precious metal catalyst (palladium, iridium, etc.) and an especially stabilized reaction partner. Here we will develop new methods that don't require stabilized reaction partners. We will use nuclear magnetic resonance spectroscopy to study the new reactions and try to understand the chemical pathways that are occurring. We expect that the information from the spectroscopic studies will be very useful in designing additional reactions. Overall, these studies will provide important new ways to rapidly synthesize a wide range of molecules with a wide variety of uses.