Exceptional Selectivities of Dirhodium Catalysts

点击翻译按钮获取中文摘要

In this project funded by the Chemical Catalysis Program of the Chemistry Division, Professor Michael P. Doyle will explore dirhodium compounds that hold transformational potential for advancements in catalysis for organic synthesis and for the understanding of their applications. The research will focus on three major initiatives. (1) The development of catalytic oxidations of organic compounds using dirhodium carboxamidate. These studies will include the elucidation and clarification of the mechanisms of oxidations by tert-butyl hydroperoxide and the design of a synthetic strategy for peroxidation/Michael addition/peroxide cleavage. (2) The development of acidic chiral dirhodium(II,III) carboxamidates for high enantioselectivity in Lewis acid catalyzed reactions, and expanding their broad use in Lewis acid catalyzed reactions (including carbonyl-ene, Henry, and azomethine cycloaddition reactions). (3) The development of an understanding of and control of catalysis that exclusively produces different products from the same reactants by the use of different catalysts (e.g., through metal carbene versus acid intermediates). A goal is to establish catalyst uniqueness in reactions of vinyldiazoacetates and to design useful predictions about how to develop new reactions..This research provides fundamental advances in catalysis and offers research opportunities for the education of graduate and undergraduate students who are preparing for careers in the chemical sciences. Students are integrated into the research program with a strong mentoring program that prepares them for their intended careers. As a platform for student education, the development of new dirhodium catalysts and their applications for highly selective processes provides new transformations, enhanced catalyst control, and specific reaction pathways. New oxidation methodologies catalyzed by dirhodium compounds promote green chemistry applications that are selective and efficient, and understanding how they occur increases the potential for uses of molecular oxygen as the oxidant. Oxidized dirhodium compounds that are prepared by mild methods provide a broad selection of effective and highly selective Lewis acids for use as catalysts in carbon-carbon bond forming transformations. The search for divergent outcomes in catalytic reactions is a concept whose applications have practical implications for catalyst comparisons in general; the uses of two or more catalysts that act independent of each other will increase the efficiency of many catalytic processes.