Multiple Metal-Carbon Bonds, Metallacycles and Catalytic Olefin Metathesis Reactions

多重金属-碳键、金属环和催化烯烃复分解反应

• 批准号: 1463707
• 负责人: Richard Schrock
• 金额: $ 60万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1463707&HistoricalAwards=false
• 关键词: Multiple; Metal; Carbon; Bonds; Metallacycles

With this award, the Chemical Catalysis Program of the Division of Chemistry is funding Professor Richard R. Schrock of the Massachusetts Institute of Technology to carry out fundamental studies on olefin metathesis catalysts based on the two earth abundant elements, molybdenum and tungsten. 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 cancers and AIDS, as well as the synthesis of specialty materials. Professor Schrock is studying ways to make the catalysts more reactive, selective, and durable 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 Schrock research group is performing synthetic, mechanistic, structural, and reactivity studies of newly designed catalysts for the olefin metathesis reaction. Four new catalyst classes are being investigated with a focus on several specific challenges in olefin metathesis catalysis: synthesizing new oxo alkylidene complexes of tungsten that are activated through binding of a Lewis acid to the oxo ligand; supporting well-defined oxo alkylidene metathesis catalysts on silica; developing imido alkylidene catalysts that contain a sterically demanding 2,6-disubstituted phenylimido ligands in order to limit reactions to ones in which only anti-alkylidene isomers can form; and creating potentially more reactive, coordinatively unsaturated cationic complexes paired with a weakly coordinating anion. Heterogeneous metathesis catalysts are employed for the largest volume metathesis reactions, but the least is known about how to prepare them as single, well-defined species on the surface and to control their reactivity at a molecular level. This research has the potential to generate new classes of metathesis catalysts and advance the general understanding of metathesis chemistry.

有了这个奖项，化学系的化学催化计划是资助教授理查德R。马萨诸塞州理工学院的Schrock等人进行了基于两种地球丰富元素钼和钨的烯烃复分解催化剂的基础研究。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癌症和AIDS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。 Schrock教授正在研究如何使催化剂比以前的任何催化剂都更具反应性，选择性和耐用性。该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方面。Schrock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。四种新的催化剂类别正在研究中，重点是烯烃复分解催化中的几个具体挑战：合成通过将刘易斯酸结合到氧代配体上而活化的钨的新的氧代亚烷基络合物;开发了含有空间要求高的2，6-二取代的苯基亚氨基配体，以便将反应限制在仅可形成反亚烷基异构体的反应中;并产生与弱配位阴离子配对的潜在更具反应性的配位不饱和阳离子络合物。 非均相复分解催化剂用于最大体积的复分解反应，但关于如何将它们制备为表面上的单一的、明确定义的物种以及在分子水平上控制它们的反应性，知之甚少。这项研究有可能产生新类型的复分解催化剂并促进对复分解化学的普遍理解。