Structurally- and Proton-Responsive Ligands for Sustainable Catalysis

我们探索了金属配体反应性的新范式，这使我们能够在催化剂中应用和开发这一行为，以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，这些键有可能用于构建香料、农用化学品和制药等增值产品。由于催化剂结构独特的金属-配体反应活性，特定类型的键结构将不同于现有的方法。我们的研究针对三种不同的金属-配体反应模式： 1.促进成键和取代反应的结构响应性配体。我们已经开发了一种结构响应型配体，我们的目标是建立配体动力学促进有机金属反应并阐明如何控制这些行为。CSP3-CSP3偶联和取代是许多催化反应中必不可少的步骤，因此有可能对催化产生广泛的影响。 2.Bronsted-碱性配体促进Ni(II)的C-H活化用于有氧氧化催化。通过Pd(II)与分子内Bronsted碱结合的氧化还原中性Csp2-H活化，C-C偶联催化发生了革命性的变化。我们的目标是探索以Ni(II)和氢氧化物为碱的Csp3-H的活化。成功的反应将只产生水作为无毒的副产物，反应将与Ni(II)促进的烯丙基与O2的氧化反应相容。这些反应加在一起，将使镍对C-H键进行前所未有的、选择性的、一步的、无添加剂的有氧氧化。 3.质子转移配体促进无添加剂分子间氢胺化反应。许多催化反应包括质子转移(PT)步骤，例如在形成C-C或C-E键的过程中。取代分子间碱基来调节PT，配体上的内部碱基消除了对添加剂的需要，并可以加快反应速度。我们的目标是应用我们在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，以合成多功能的亚胺和烯胺产品。

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.