Asymmetric Catalysis by Chiral-Polymer-Induced and Stabilized, Chiral-Surface Nanoclusters

0756633陈，尤金Y. 总体目标。该提案解决了催化的巨大挑战：开发多金属，纳米簇“多相”催化剂，可以实现高%ee催化不对称合成的目标。新型螺旋手性聚合物将被合成和开发，因为它们能够诱导和稳定手性表面纳米团簇用于不对称催化。这些进展将反过来推动对科学界及其所服务的行业具有重要意义的新型不对称催化剂的合理开发。此外，本文的研究将发现多金属不对称催化剂的关键原理和概念。本提案的具体目标是调查三个主要假设：（i）在特别设计的新型手性聚合物存在下，Pt和Ir纳米团簇的成核和生长将允许手性表面纳米团簇的上级诱导以及比迄今可能的更好的稳定化，由于手性聚合物的nm长度尺度与纳米团簇的手性扭结点表面的nm长度尺度相匹配，（ii）已知的多金属优选反应，例如苯氢化催化，也已知在Pt和Ir纳米簇中，可以扩展到前手性间烷基酚的纳米簇不对称还原，作为多金属不对称催化的原型测试反应，一个感兴趣的有机社区和他们服务的行业的反应;和（iii）的性质的手性催化剂将是纳米团簇与螺旋手性，扭结网站表面的惠顿型，目前，一个未被识别的，未研究的，因此完全未开发的新类别的多金属不对称催化剂。一个NSF团队已经组装了所需的科学专业知识和物理方法的广度为这个大挑战：3个共同PI从科罗拉多州立大学（CSU），教授。E.陈河，巴西-地Finke和T. Rovis和来自太平洋西北国家实验室（PNNL）的合作者J. Linehan博士以及他的三位同事J.富尔顿、W. Shaw和S.凯斯曼这个NSF团队的综合协同专业知识涵盖：纳米科学;材料、无机、有机和聚合物化学;催化;不对称、纳米簇和手性聚合物合成;动力学和机理;先进的操作表征方法;和计算化学。拟议研究的智力价值至少包括3个组成部分：首先，概述的研究将检查和利用在手性配体存在下生长纳米团簇将产生一类新的多金属、不对称催化剂的高可能性，所述催化剂是固有手性的;第二，本NSF建议的前所未有的方面包括开发新型的官能化手性螺旋聚合物，用于手性表面纳米团簇的上级诱导和更好的稳定，其可用于催化重要的不对称反应;第三，概述的研究也将有望推进多金属表面位置的基础知识，该研究的更广泛的影响至少有4个方面，包括：（i）通过阐明多金属不对称催化的指导原则和概念来发现和理解;（ii）通过将研究与教育结合起来进行教学，培训和学习，这些领域涵盖了现代化学科学家在解决当今广泛问题时所需的大部分内容。此外，代表性不足、多样化和本科生将接受上级科学方法的培训，这种方法最能发展当今问题所要求的思维和分析的深度，即对多种备选假设的反证;（iii）将发展网络和伙伴关系，以加强研究和教育的基础设施，特别是与国家实验室PNNL的伙伴关系，以及与CSU合作的3个少数民族服务机构，CSU Pueblo，刘易斯堡College和新墨西哥州Highlands University;以及（iv）拟议的工作也将对社会产生广泛的影响，因为研究是在化学催化，一个对我们现代生活方式至关重要的领域，全球每年估计有10万亿美元的经济影响。

0756633 Chen, Eugene Y. Overall Objectives. This proposal addresses a Grand Challenge of catalysis: the goal of developing polymetallic, nanocluster "heterogeneous" catalysts that can achieve high %ee catalytic asymmetric synthesis. Novel helical chiral polymers will be synthesized and exploited for their ability to induce, as well as stabilize, chiral-surface nanoclusters for asymmetric catalysis. Those advances will, in turn, fuel the rational development of new asymmetric catalysts of significance to the scientific community and the industries they service. In addition, the studies herein will discover key principles and concepts underlying polymetallic asymmetric catalysts.The Specific Objectives of this proposal are to investigate three dominant hypotheses: (i) that the nucleation and growth of Pt and Ir nanoclusters, in the presence of specifically designed novel chiral polymers, will allow both superior induction as well as better stabilization of chiral-surface nanoclusters than heretofore possible, due to the match of the nm length scale of the chiral polymer with the nm length scale of the nanocluster's chiral kink-site surface; (ii) that known polymetallic preferring reactions, such as benzene hydrogenation catalysis, that are also known in Pt and Ir nanoclusters, can be extended to nanocluster asymmetric reduction of prochiral meta-alkylphenols as a prototype test reaction of polymetallic asymmetric catalysis, a reaction of interest to the organic community and the industries that they service; and (iii) that the nature of the chiral catalyst will be nanoclusters with helically chiral, kink-site surfaces of the Whetten type that are, at present, an unrecognized, unstudied and thus completely undeveloped new class of polymetallic asymmetric catalysts.NSF Team and Its Associated Expertise and Experimental Methods. An NSF Team has been assembled with the required breadth of scientific expertise and physical methods for this Grand Challenge: 3 co-PIs from Colorado State University (CSU), Profs. E. Chen, R. Finke, and T. Rovis, and a collaborator from Pacific Northwest National Laboratories (PNNL), Dr. J. Linehan plus 3 of his colleagues J. Fulton, Dr. W. Shaw, and Dr. S. Kathmann. This NSF Team's combined synergistic expertise spans: nanoscience; materials, inorganic, organic and polymer chemistries; catalysis; asymmetric, nanocluster and chiral-polymer synthesis; kinetics and mechanism; advanced operando characterization methods; and computational chemistry.The Intellectual Merit of the proposed research consists of at least 3 components: first, the studies outlined will examine and exploit the high probability that growing nanoclusters in the presence of chiral ligands will yield a new class of polymetallic, asymmetric catalysts that are inherently chiral; second, unprecedented aspects of the present NSF proposal include the exploitation of novel, functionalized chiral helical polymers for both superior induction and better stabilization of chiral-surface nanoclusters that can be used to catalyze important asymmetric reactions; and third, the studies outlined will also promise to advance fundamental knowledge of the surface sites of polymetallic, nanocluster catalysts.The Broader Impacts of the research are at least 4 fold and include its impacts on: (i) discovery and understanding by elucidating the guiding principles and concepts underlying the very timely area of polymetallic asymmetric catalysis; (ii) teaching, training, and learning via an integration of research with education in areas which span much of what is required of a modern chemical scientist when addressing today's broad problems. Moreover, underrepresented, diversity, and undergraduate students will be trained in the superior scientific method which best develops the depth of thought and analysis also required by today's problems, namely the disproof of multiple alternative hypotheses; (iii) networks and partnerships will be developed which will enhance the infrastructure for research and education, notably the partnerships with a National Lab, PNNL, and with the 3 minority serving institutions that CSU partners with, CSU Pueblo, Fort Lewis College, and New Mexico Highlands University; and (iv) the proposed work will also achieve a broad impact on society since the research is in chemical catalysis, an area central to our modern way of life, one with an estimated economic impact of 10 trillion dollars per year worldwide.