Ligand-Facilitated Palladium Oxidation Catalysis

描述（由申请人提供）：氧化反应是合成有机化学中最强大的转化之一，因为它们能够增加有机底物的功能。然而，许多有用的化学计量氧化剂的高成本和毒性促使了大量的努力，以发展催化转化，使用现成的和环境友好的氧化剂。一种新的有氧底物氧化途径是配体促进的钯氧化催化。这些反应不需要氧化还原介质，如氯化铜或苯醌在催化周转过程中对钯(0)进行二氧偶联氧化。本研究将探讨配体促进钯氧化催化烯烃底物氧化杂环化和碳环化的范围和用途。这项工作将通过实验室开发的新的平行筛选工具和同时详细的催化反应机理表征来促进。在有待开发的反应中，有新的钯催化的分子间氧化氮转移反应，该反应采用双氧作为化学计量氧化剂。以双氧为化学计量氧化剂的新型催化氧化在有机化学中具有无限的潜力，特别是在天然产物和生物活性分子的合成方面。未来对不对称催化的扩展将对药物发现工作产生重大影响。这些反应是环境友好的，因为它们的良性副产品（水）。这些优点，加上低成本和低毒性的双氧，将使配体促进的钯氧化催化对工业界和学术界的合成有机化学家非常有吸引力。

DESCRIPTION (provided by applicant): Oxidation reactions are among the most powerful transformations in synthetic organic chemistry because of their ability to increase the functionality of organic substrates. However, the high costs and toxicity of many useful stoichiometric oxidants have prompted substantial effort to develop catalytic transformations that employ readily available and environmentally benign oxidants. A novel pathway for aerobic substrate oxidation is ligand-facilitated palladium oxidation catalysis. These reactions require no redox mediators such as copper(ll) chloride or benzoquinone for dioxygen-coupled oxidation of palladium(0) during catalytic turnover. The proposed research will examine the scope and utility of ligand-facilitated palladium oxidation catalysis for the oxidative hetero- and carbocyclization of olefinic substrates. This work will be facilitated by new parallel screening tools developed in the lab and simultaneous detailed mechanistic characterization of the catalytic reactions. Among the reactions to be developed are new palladium-catalyzed intermolecular oxidative nitrogen-transfer reactions that employ dioxygen as the stoichiometric oxidant. New catalytic oxidations that employ dioxygen as the stoichiometric oxidant have almost unlimited potential in organic chemistry, particularly for the synthesis of natural products and biologically active molecules. Future expansions into asymmetric catalysis would have a significant impact on drug discovery efforts. These reactions are environmentally friendly as well due to their benign by-products (water). These assets, along with the low cost and toxicity of dioxygen, will make ligand-facilitated palladium oxidation catalysis quite attractive to synthetic organic chemists in industry as well as those in academia.