Structurally- and Proton-Responsive Ligands for Sustainable Catalysis

用于可持续催化的结构和质子响应配体

• 批准号: RGPIN-2020-06147
• 负责人: Blacquiere, Johanna
• 金额: $ 3.5万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747783
• 关键词: Structurally; Proton; Responsive; Ligands; Sustainable

We explore new paradigms in metal ligand reactivity, which allows us to apply and exploit this behaviour in catalysts for the construction of synthetically valuable functionalities. Target transformations include C-C, C-N and C-O bond formations that have the potential to be used in the construction of value-added products such as fragrances, agrochemicals and pharmaceuticals. The specific types of bond constructions will be distinct from existing methods due to the unique metal-ligand reactivity of the catalyst structures. Our research targets three distinct modes of metal-ligand reactivity: 1. Structurally-Responsive Ligands to Promote Bond Formation and Substitution Reactions. We have developed a structurally-responsive ligand and we aim to establish that the ligand dynamics promote organometallic reactions and to elucidate how to control these actions. The exemplar reactions will be Csp3-Csp3 coupling and substitution, which are essential steps in many catalytic reactions and thus have the potential for broad impact to catalysis. 2. Bronsted-Basic Ligands to Promote C-H Activation with Ni(II) for Aerobic Oxidation Catalysis. C-C coupling catalysis has been revolutionized by redox neutral Csp2-H activation by Pd(II) in concert with an intramolecular Bronsted base. We aim to explore Csp3-H activation with Ni(II) and hydroxide as the base. A successful reaction would give only water as an innocuous by-product and the reaction would be compatible with Ni(II) promoted allylic oxidation with O2. Together these reactions would give the unprecedented, selective, one-step, additive-free aerobic oxidation of C-H bonds by nickel. 3. Proton-Transfer Ligands to Promote Additive-Free Intermolecular Hydroamination. Many catalytic reactions include proton-transfer (PT) steps en route to, for example, C-C or C-E bond formation. Instead of an intermolecular base to mediate PT, an internal base on the ligand eliminates the need for additives and can accelerate reaction rates. We aim to apply our experience with PT ligands to develop Ru and Fe catalysts for selective C-N bond formation to give synthetically versatile imine and enamine products.

我们探索金属配体反应性的新范例，这使我们能够在催化剂中应用和利用这种行为来构建具有合成价值的功能。目标转化包括 C-C、C-N 和 C-O 键的形成，这些键的形成有可能用于构建增值产品，如香料、农用化学品和药品。由于催化剂结构独特的金属-配体反应性，特定类型的键结构将不同于现有方法。我们的研究针对金属-配体反应的三种不同模式： 1. 促进键形成和取代反应的结构响应配体。我们开发了一种结构响应配体，我们的目标是确定配体动力学促进有机金属反应并阐明如何控制这些行为。示例反应是 Csp3-Csp3 偶联和取代，它们是许多催化反应中的重要步骤，因此可能对催化产生广泛影响。 2. 布朗斯台德碱性配体促进 Ni(II) 的 C-H 活化，用于有氧氧化催化。 Pd(II) 与分子内布朗斯台德碱协同作用，氧化还原中性的 Csp2-H 活化彻底改变了 C-C 偶联催化。我们的目标是探索以 Ni(II) 和氢氧化物为碱的 Csp3-H 活化。成功的反应将仅产生水作为无害副产物，并且该反应与 Ni(II) 促进的 O2 烯丙基氧化相容。这些反应共同实现了镍对 C-H 键的前所未有的、选择性的、一步式的、无添加剂的有氧氧化。 3.促进无添加剂分子间氢胺化的质子转移配体。许多催化反应包括在形成 C-C 或 C-E 键等过程中的质子转移 (PT) 步骤。配体上的内部碱基取代了介导 PT 的分子间碱基，无需添加剂，并且可以加快反应速率。我们的目标是运用我们在 PT 配体方面的经验来开发用于选择性 C-N 键形成的 Ru 和 Fe 催化剂，从而提供合成用途广泛的亚胺和烯胺产品。