Size Selective Macrocyclic Catalysts

通过这个奖项，美国国家科学基金会化学部的化学催化和化学合成项目支持纽约州立大学布法罗分校的Steven T. Diver教授的研究。戴弗教授正在研究新催化剂的开发，它们的反应方式，以及使用新方法合成生物活性化合物，如来自大自然的产品（天然产品）。这个项目采用了一种受酶启发的催化新方法。在有机合成中，催化剂用于加速反应并使新的化学转化成为可能。在自然界中，酶是基于蛋白质的催化剂，它在三维空间中定位其反应基团以促进化学反应。酶在与之结合的起始物质中具有很强的特异性，因为它们创造了一个识别和促进化学反应的微环境。在这个项目中，戴弗博士将一个著名的金属结合基团定位在一个巨大的合成分子腔中。该空腔为结合金属催化的反应创造了独特的化学和空间环境。活性金属中心周围的环境被用来根据分子的大小来区分分子。这种方法提供了一种获得选择性的方法，而不是以前的非选择性化学反应。这个项目是在一个多样化和激发智力的研究环境中培养科学家。戴弗教授正在实施一项新的教师认证计划，旨在为新的博士毕业生提供教学经验，以改善小型学院和社区学院的教学效果，因为这些地方需要高质量的教师。在初级一级的其他推广工作包括发展对分子及其在社会中的功能和用途的科学认识。有机合成中的一个主要挑战是区分两个相同官能团的反应性的能力。该奖项旨在通过开发位于大环腔内的新型催化剂，在交叉烯烃复分解和其他反应的背景下解决这一问题。取向和金属结合是由一个n -杂环碳配体（NHC）提供的，它被纳入到大环中。NHC配体用途广泛，存在于许多不同的过渡金属配合物中，包括用于烯烃复分解的钌（Ru）催化剂。虽然这是一种应用广泛且重要的反应，但具有相似反应活性的两种烯烃之间的交叉复合反应存在局限性。这个项目是利用大小控制，可能与酶，区分烯烃-一个新的方法来解决选择性交叉烯烃复分解问题。尺寸选择性原理也被应用于其他金属催化反应，如钯催化的交叉偶联，其中尺寸控制可以防止副反应。交叉偶联反应和烯烃复合反应是合成药物化合物、分子探针、天然产物和材料等新分子的两种最重要的反应。最终，催化技术的进步将使先进的化工生产变得更便宜、更可预测、更高效。除了这些更广泛的科学影响外，该项目还促进了不同背景学生的招募，鼓励小学生的科学素养，并实现了一项专门针对化学教师的培训计划，旨在改善新博士毕业生进入大学教学职业的准备和安置。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemical Catalysis and Chemical Synthesis Programs of the NSF Division of Chemistry are supporting the research of Professor Steven T. Diver of the State University of New York at Buffalo. Professor Diver is studying the development of new catalysts, the ways they react, and the use of new methods for the synthesis of biologically-active compounds such as products derived from nature (natural products). This project takes a new approach to catalysis inspired by enzymes. In organic synthesis, catalysts are used to speed up reactions and make new chemical transformations possible. In Nature, enzymes are protein-based catalysts that orient their reactive groups in three-dimensional space to facilitate a chemical reaction. Enzymes have great specificity in the starting materials they bind with as they create a microenvironment that recognizes and facilitates chemical reactions. In this project, Dr. Diver is positioning a well-known metal binding group inside a large, synthetic, molecular cavity. The cavity creates a unique chemical and spatial environment for reactions catalyzed by the bound metal. The environment surrounding the reactive metal center is being used to differentiate molecules based on their size. This approach is providing a way to gain selectivity over previously unselective chemical reactions. This project is educating scientists in a diverse and intellectually-stimulating research environment. Professor Diver is implementing a new teacher certification program designed to give new Ph.D. graduates experience in teaching that will improve outcomes at small colleges and community colleges, where quality teachers are needed. Additional outreach efforts at the elementary level include developing scientific awareness of molecules and their functions and uses in society.A major challenge in organic synthesis is the ability to differentiate reactivity between two of the same functional group. This award is addressing this problem in the context of cross alkene metathesis and other reactions through the development of new catalysts located inside macrocyclic cavities. The orientation and metal binding is provided by an N-heterocyclic carbene ligand (NHC), which is incorporated into the macrocycle. NHC ligands are highly versatile and found in many different transition metal complexes, including ruthenium (Ru) catalysts for alkene metathesis. Though a widely used and important reaction, there are limitations in cross metathesis between two alkenes that have similar reactivity. This project is utilizing size control, possible with enzymes, to differentiate alkenes - a new approach to the problem of selective cross alkene metathesis. The principle of size-selectivity is also being applied to other metal-catalyzed reactions such as palladium-catalyzed cross couplings, where size control can prevent side reactions. Cross coupling and alkene metathesis are two of the most important reactions for synthesizing new molecules such as medicinal compounds, molecular probes, natural products, and materials. Ultimately, improvements in catalysis make advanced chemical manufacturing cheaper, more predictable, and more efficient. In addition to these scientific broader impacts, this project facilitates the recruitment of students of diverse backgrounds, encourages science literacy in elementary schoolers, and enables a chemistry-specific teacher training program designed to improve preparedness and placement of new Ph.D graduates into college teaching careers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.