Mechanisms of Transition Metal Catalyzed Reactions in Hydrocarbons

有了这个奖项，化学系的化学催化项目将资助加州理工学院的Robert H. Grubbs教授开展基于钌元素的烯烃复分解催化剂的基础研究。烯烃（含有碳-碳双键的有机化合物）是许多重要有机化合物的关键链接，用于制药，商品化学品和高分子材料。烯烃复分解是有机分子中碳-碳双键断裂并重新排列的反应。烯烃复分解反应彻底改变了与治疗丙型肝炎和艾滋病等疾病的天然和非天然产物相关的有机分子的合成，以及特种材料的合成。Grubbs教授正在研究如何使催化剂比以往任何催化剂更具活性和选择性。这项研究的广泛影响可能是广泛的，在化学科学中进一步发挥烯烃转化的作用，推进烯烃转化的商业用途，以及培训和教育学生。Grubbs研究小组正在对新设计的烯烃分解反应催化剂进行合成、机理、结构和反应性研究。目前这一代的催化剂是高活性的，但往往产生不同异构体的混合物。近年来，在高收率、高立体选择性合成烯烃z型异构体催化剂的研究方面取得了很大进展，但制备能选择性合成e型异构体的催化剂却比较困难。在理论建模的指导下，用于开发z选择性催化剂的策略正在被修改，以设计新的配合物，目标是达到e选择性体系。金属环上取代基的几何形状控制了反应中产生的双键的几何形状。在z选择性催化剂中，螯合配体系统迫使金属环和n杂环碳配体在一起，使得中间金属环上的所有取代基都被强迫到金属环的一侧。在目前的工作中，Grubss教授使用相同的设计策略来形成配体阵列，迫使取代基在金属环中相互反式，从而得到反式(E)烯烃。除了e选择性催化剂的应用之外，通往它们的途径将测试并拓宽控制催化剂选择性和活性因素的机制模型。

With this award, the Chemical Catalysis Program of the Division of Chemistry is funding Professor Robert H. Grubbs of the California Institute of Technology to carry out fundamental studies on olefin metathesis catalysts based on the element, ruthenium. Olefins (organic compounds containing carbon-carbon double bonds) are a key linkage in many important organic compounds that are used for pharmaceuticals, commodity chemicals and polymeric materials. Olefin metathesis is a reaction that consists of breaking and rearranging carbon-carbon double bonds in organic molecules. The olefin metathesis reaction has revolutionized the synthesis of organic molecules relevant to natural and unnatural products for treatment of diseases such as hepatitis C and AIDS, as well as the synthesis of specialty materials. Professor Grubbs is studying ways to make the catalysts more reactive and selective than any previous catalysts. The broader impacts of the research could be wide ranging in terms of furthering the role of olefin metathesis in chemical science, advancing commercial uses of olefin metathesis, and training and educating students.The Grubbs research group is performing synthetic, mechanistic, structural, and reactivity studies of newly designed catalysts for the olefin metathesis reaction. The present generation of catalysts is highly active but tends to give a mix of different isomers. Over the past several years, considerable progress has been made in developing catalysts for the synthesis of Z-isomers of olefins in high yield and stereoselectivity, but to make a catalyst that selectively makes the E-isomer has proven to be more difficult. The strategies used to develop Z-selective catalysts are being modified, with guidance from theoretical modeling, to design new complexes with the goal of reaching an E-selective system. The geometry of the substituents on the metallacycle controls the geometry of the double bond produced in the reaction. In the Z-selective catalyst, chelated ligand systems force the metallacycle and the N-heterocyclic carbene ligand together so that all the subsitutents on the intermediate metallacycle are forced to one side of the metallacycle. In the present work, Professor Grubss is using the same design strategies to form ligand arrays that force the substituents trans to each other in the metallacycle so that the resulting olefin will be trans (E). In addition to the applications of the E-selective catalysts, the pathway to them will test and broaden the mechanistic model for the factors that control catalyst selectivity and activity.