Fluxionality-Induced Enantiomerisation in Ligand Design

如果一个分子或材料在其镜像上是不可叠加的，那么它就是手性的。这一属性是控制治疗剂、催化剂和电子设备功能的关键手柄。手性有机分子中用途最广、用途最广的结构单元是SP3杂化碳中心。一方面，它们的四面体几何结构是制造形状持久、坚固的结构的理想选择，这些结构可以高保真地传递3D立体化学信息。但另一方面，它们缺乏其他立体合成元件(螺旋、手性平面等)所具有的能力。在它们的镜像形式之间来回切换。菲尔德通过开创以流动碳为中心的立体化学来弥合这一知识鸿沟。它开发了刚性小分子的合成、分析和应用，这些小分子在它们的镜像结构之间快速飞行，经历了流变性诱导的对映。菲尔德确立了获得和利用流动手性碳笼的基本规则。它列举了一系列预计将经历这种类型转化的分子结构，确定了调整动力学、改善对映体之间的3D区分以及将笼子连接到其他分子组件的方法。重要的是，它开发了将刚性笼子的动态性质传递给立体生成的过渡金属离子的方法，拓宽了它们的应用范围。由此得到的刺激响应型手性络合物具有潜在的性质，可用于放大不对称催化中的对映体诱导，以及用于手性材料的信息写入和读取。总体而言，菲尔德通过形成既是刚性笼子又具有可模塑手性的矛盾结构，重新思考了有机化学的一个基本方面。

A molecule or material is chiral if it is nonsuperimposable on its mirror image. This property is a key handle for controlling the function of therapeutics, catalysts, and electronic devices. The most versatile and widely used structural units in chiral organic molecules are sp3-hybridised carbon centres. On one hand, their tetrahedral geometry is ideal for making shape-persistent, inflexible structures that transmit 3D stereochemical information with high fidelity. But on the other hand, they lack an ability present in other stereogenic elements (helices, chiral planes, etc.) of flipping between their mirror-image forms. FIELD bridges this knowledge gap by pioneering fluxional carbon-centred stereochemistry. It develops the synthesis, analysis, and applications of rigid small molecules that rapidly flit between their mirror-image structures, undergoing fluxionality-induced enantiomerisation. FIELD establishes the ground rules for obtaining and exploiting fluxionally chiral carbon cages. It enumerates a series of molecular structures that are predicted to undergo this type of transformation, identifying ways to tune the dynamics, improve 3D differentiation between enantiomers, and connect the cages to other molecular components. Importantly, it develops ways to transmit the dynamic properties of the rigid cages to stereogenic transition metal ions, broadening the scope for their applications. The resulting stimulus-responsive fluxionally chiral complexes have properties that are potentially useful for amplifying the enantioinduction in asymmetric catalysis, and for writing and reading information with chiroptical materials. Overall, FIELD rethinks a fundamental aspect of organic chemistry by forming paradoxical structures that are simultaneously rigid cages, while also having mouldable chirality.