Mechanisms of Transition Metal Catalyzed Reactions in Hydrocarbons

过渡金属催化烃类反应的机理

• 批准号: 1502616
• 负责人: Robert Grubbs
• 金额: $ 60万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1502616&HistoricalAwards=false
• 关键词: Mechanisms; Transition; Metal; Catalyzed; Reactions

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.

有了这个奖项，化学部的化学催化计划是资助教授罗伯特H。Grubbs的加州理工学院进行基础研究的烯烃复分解催化剂的基础上的元素，钌。烯烃（含有碳-碳双键的有机化合物）是许多重要有机化合物中的关键键，用于药物、日用化学品和聚合物材料。 烯烃复分解反应是一个由有机分子中碳-碳双键断裂和重排组成的反应。烯烃复分解反应已经彻底改变了与用于治疗疾病如丙型肝炎和艾滋病的天然和非天然产物相关的有机分子的合成，以及特殊材料的合成。 Grubbs教授正在研究如何使催化剂比以前的任何催化剂更具反应性和选择性。研究的更广泛的影响可能是广泛的，在促进烯烃复分解在化学科学中的作用，推进烯烃复分解的商业用途，以及培训和教育学生。Grubbs研究小组正在进行新设计的烯烃复分解反应催化剂的合成，机理，结构和反应性研究。 目前这一代催化剂是高活性的，但往往会产生不同异构体的混合物。 在过去的几年中，在开发用于以高产率和立体选择性合成烯烃的Z-异构体的催化剂方面已经取得了相当大的进展，但是制备选择性地制备E-异构体的催化剂已经被证明是更加困难的。 用于开发Z-选择性催化剂的策略正在修改，以理论建模为指导，设计新的络合物，目标是实现E-选择性系统。 金属配体上取代基的几何形状控制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乳糖和N-杂环卡宾配体在一起，使得中间体金属乳糖上的所有取代基被迫位于金属乳糖的一侧。在目前的工作中，Grubss教授正在使用相同的设计策略来形成配体阵列，这些配体阵列迫使金属乳糖中的取代基相互反式，从而产生的烯烃将是反式（E）。 除了E-选择性催化剂的应用外，它们的途径将测试和拓宽控制催化剂选择性和活性的因素的机理模型。