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

迈阿密大学牛津校区教授王宏在化学系化学催化(CAT)计划的支持下，开发了将金属中心和单分子上的有机催化中心结合在一起的双功能催化剂，在不对称有机转化中具有潜在的应用前景。合成了双功能烯胺-金属Lewis酸催化剂，用于不对称碳-碳和碳-杂原子键的形成，离不开这两个催化中心的协同作用。将研究与酮的直接Aldol缩合反应和反电子需求的异Diels-Alder反应。催化剂的设计允许不同的胺基与不同的金属结合，这使得这些双功能催化体系的适用范围扩大到广泛的有机反应。路易斯酸-刘易斯碱双功能体系的开发具有挑战性，因为酸和碱容易发生自猝灭和失活。拟议的研究承诺通过明智的分子结构来绕过这个问题，该结构具有足够的灵活性，使有机碱和金属Lewis酸接近，但具有足够的刚性和空间位阻，以防止它们的结合。这项拟议的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。这些成果将被整合到一门新的催化研究生课程中，并将实施一项推广计划，为来自德克萨斯农工大学金斯维尔分校的少数族裔本科生及其教师以及地区高中的高中教师提供暑期研究经验。

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.