NSF Career: Enamine-Metal Lewis Acid Bifunctional Catalysts for Asymmetric Organic Transformations

迈阿密大学牛津校区的Hong Wang教授得到化学系化学催化（CAT）项目的支持，开发了在单个分子上结合金属中心和有机催化中心的双功能催化剂，用于不对称有机转化的潜在应用。将合成双官能烯胺-金属刘易斯酸催化剂，并将其用于不对称碳-碳和碳-杂原子键形成反应，如果没有两个催化中心的协同作用，这些反应就不能实现。我们将研究直接羟醛缩合反应和反电子需求的异Diels-桤木反应。催化剂设计允许不同胺碱与不同金属的组合，这拓宽了这些双功能催化体系对广泛的有机反应的适用性范围。刘易斯酸-刘易斯碱双功能体系的开发具有挑战性，因为酸和碱易于自猝灭和失活。拟议中的研究有望通过明智的分子结构来规避这个问题，这些分子结构具有足够的灵活性，可以使有机碱和金属刘易斯酸非常接近，但具有足够的刚性和空间位阻，可以防止它们结合。这项研究可能会对不对称催化以及精细化学品和药物的合成产生重大影响。研究结果将被纳入一个新的催化研究生课程，并将实施一项推广计划，为德克萨斯州A M大学金斯维尔分校的少数民族本科生及其教师和地区高中的高中教师提供夏季研究经验。

Professor Hong Wang of Miami University Oxford Campus is supported by the Chemical Catalysis (CAT) Program in the Division of Chemistry to develop bifunctional catalysts combining a metal center with an organocatalytic center on a single molecule for potential applications in asymmetric organic transformations. Bifunctional enamine-metal Lewis acid catalysts will be synthesized and used for asymmetric carbon-carbon and carbon-heteroatom bond forming reactions which cannot be achieved without the synergistic action of the two catalytic centers. Direct aldol condensations with ketones and inverse-electron-demand hetero-Diels-Alder reactions will be investigated. The catalyst design allows for the combination of different amine bases with different metals, which broadens the spectrum of applicability of these bifunctional catalytic systems to a wide range of organic reactions. The development of Lewis acid-Lewis base bifunctional systems is challenging because the acid and the base are prone to self-quenching and inactivation. The proposed research promises to circumvent this problem by judicious molecular architecture with sufficient flexibility to bring the organic base and the metal Lewis acid into close proximity but with enough rigidity and steric hindrance to prevent their binding. The proposed research could significantly impact asymmetric catalysis and the synthesis of fine chemicals and pharmaceuticals. The results will be integrated into a new graduate course in catalysis and an outreach plan will be implemented to provide summer research experience to minority undergraduate students and their teachers from Texas A&M University-Kingsville and to high school teachers from area high schools.