CATALYTIC METALLO-BIOMIMETIC SITES IN POROUS HOSTS

这项研究的目的是通过将金属络合物固定在多孔性有机载体上来开发新型仿生催化剂。这项研究将着重于加氧酶化学，特别是那些涉及C-H键活化和环氧化的反应，以产生具有潜在药用价值的光学纯分子。建议的体系将使用模板共聚方法，其中固定化中心的形成发生在聚合过程中。我们认为，这种方法是模拟蛋白质中发现的金属中心的一种有效方法，并且可以设计系统来模拟金属蛋白质中发现的各种结构特征，包括催化金属中心的位置隔离、孔隙度和金属络合物周围微环境的控制。催化金属中心周围独特的微环境是在聚合过程中产生的，并在体系形成后由有机主体保持。这些高度结构化的活性中心可用于调节外源配体与固定化金属络合物的结合(以及随后的化学作用)。因此，可以产生在溶液衍生的低分子量复合体中通常观察不到的仿生无机物种。这项工作的长期目标是设计和合成包含在蛋白质中发现的外源配体(底物)选择性的系统，但能够在大多数生物分子不稳定和不活跃的条件下发挥作用。金属蛋白执行尚未在合成系统中实现的化学反应。这种化学多样性至少部分源于蛋白质通过调节微环境来调节其金属中心的反应性的能力。因此，生物上重要的金属蛋白的功能和丧失功能可以在其微环境变化的背景下被理解。这种类型的分析需要进行基本的反应性研究，其中可以如本文所述单独分析单个组分的影响。

The aim of this proposed research is to develop new biomimetic catalysts by immobilizing metal complexes in porous organic hosts. The research will emphasize oxygenase chemistry especially those reactions involving C-H bond activation and epoxidation to produce optically pure molecules of potential pharmaceutical importance. The proposed systems will be made using a template copolymerization methodology where the formation of the immobilized sites occurs during polymerization. We propose that this method is an effective way to model metal sites found in proteins and that systems can be designed to simulate various architectural features found in metalloproteins, including site isolation of catalytic metal sites, porosity, and control of the microenvironments around the metal complexes. The unique microenvironments around the catalytic metal sites are created during polymerization and are maintained by the organic hosts after systems are formed. These highly structured active sites can be used to regulate exogenous ligand binding (and subsequent chemistry) to the immobilized metal complexes. Thus biomimetic inorganic species can be produced that are not normally observed in solution-derived, low molecular weight complexes. The long-range objective of this work is to design and synthesize systems that contain exogenous ligand (substrate) selectivity found in proteins yet are able to function under conditions where most biomolecules are unstable and inactive. Metalloproteins perform chemical reactions that have yet to be achieved in synthetic systems. This chemical versatility follows at least in part from the ability of the proteins to regulate the reactivity of their metal centers by adjustments of their microenvironment. Thus the function and disfunction of biologically-important metalloproteins can be understood in the context of changes in their microenvironments. This type of analysis necessitates basic reactivity studies in which the effects of single components can be analyzed individually as described herein.