Oxidation of organics catalyzed by earth--abundant transition metal ions

土--丰富的过渡金属离子催化有机物的氧化

• 批准号: RGPIN-2021-03476
• 负责人: Ottenwaelder, Xavier
• 金额: $ 2.62万
• 依托单位: Concordia University
• 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=748477
• 关键词: Oxidation; organics; catalyzed; earth; abundant

Creating value-added chemicals by efficient, selective and environmentally friendly modifications of chemical feedstock remains an urgent challenge that requires new types of catalysts. A particularly important group of reactions are oxidations of organic compounds into oxygen and nitrogen-containing molecules. Owing to the prevalence of carbon-oxygen (C-O) and carbon-nitrogen (C-N) bonds in platform chemicals, pharmaceuticals and natural products, the introduction of O and N groups into organic scaffolds is an important topic in organic synthesis. In this program, we design novel oxidative processes for the creation of such bonds that are catalytic and selective. We also aim to use wasteless oxidants such as air or hydrogen peroxide and earth-abundant, low-toxicity metals such as copper and iron. The proposed research targets three objectives: - Objective 1: To develop catalytic oxidations using the N-O bond as an activator. This objective will focus on designing metal catalysts where an N-O bond facilitates the key oxidation step on the substrate. We will focus on alcohol oxidations, as well as additions of nitrogen groups to phenols and alkenes to create nitrogen-containing molecular building blocks. - Objective 2: To understand the selectivity of C-C and C-O coupling reactions on metal-radical complexes. Such reactions pertain to oxidative metallo-enzymes and are important in synthetic strategies (for example, polyphenylene ethers are synthesized at a multi-million ton scale and cross dehydrogenative coupling reactions are essential for fine chemical synthesis). - Objective 3: To develop green, catalytic C-C and C-O bond formation reactions on phenols and their derivatives. The use of solvents has consistently been highlighted as a major pitfall of the fine chemical industry because of the waste generated by processing solutions. We thus wish to apply solvent-free methods to develop green processes in oxidative phenol chemistry. The goal is to create new methodologies for the conversion of phenols into value-added chemicals under practical conditions. The common theme of this program is the use of redox-active ligands, i.e. ligands that possess their own redox properties, including radicals. The innovation of this program lies in the systematic use of these ligands in the context of metal-based oxidation catalysis. We place a strong emphasis on phenols because the industry lacks methods to convert them efficiently and selectively into useful building blocks. The long-term outcome of this work will be to use phenols derived from the lignin fraction of biomass because it represents the only viable source to renewably produce value-added aromatic compounds on which society depends. This comprehensive program combines coordination chemistry and organic methodology within my expertise and provides multi-disciplinary and collaborative training for highly qualified personnel of all backgrounds.

通过对化学原料进行高效、选择性和环境友好的改性来生产增值化学品仍然是一个紧迫的挑战，需要新型催化剂。一组特别重要的反应是将有机化合物氧化成含氧和含氮分子。由于碳-氧（C-O）和碳-氮（C-N）键在平台化学品、药物和天然产物中普遍存在，将O和N基团引入有机支架中是有机合成中的一个重要课题。在这个项目中，我们设计了新颖的氧化过程来创建此类催化和选择性的键。我们还致力于使用无浪费的氧化剂（例如空气或过氧化氢）以及地球上储量丰富的低毒金属（例如铜和铁）。拟议的研究针对三个目标： - 目标 1：使用 N-O 键作为活化剂开发催化氧化。这一目标将集中于设计金属催化剂，其中 N-O 键促进基材上的关键氧化步骤。我们将重点关注醇的氧化，以及向酚和烯烃中添加氮基团以产生含氮分子构件。 - 目标 2：了解 C-C 和 C-O 偶联反应对金属自由基配合物的选择性。此类反应与氧化金属酶有关，在合成策略中很重要（例如，聚苯醚的合成规模为数百万吨，交叉脱氢偶联反应对于精细化学合成至关重要）。 - 目标 3：开发酚及其衍生物的绿色催化 C-C 和 C-O 键形成反应。由于加工溶液产生废物，溶剂的使用一直被认为是精细化工行业的一个主要缺陷。因此，我们希望应用无溶剂方法来开发氧化苯酚化学的绿色工艺。目标是创建在实际条件下将苯酚转化为增值化学品的新方法。该计划的共同主题是使用氧化还原活性配体，即具有自身氧化还原特性（包括自由基）的配体。该项目的创新之处在于在金属基氧化催化背景下系统地使用这些配体。我们非常重视苯酚，因为该行业缺乏将其有效且有选择性地转化为有用的结构单元的方法。这项工作的长期成果将是使用源自生物质木质素部分的酚类，因为它是可再生生产社会所依赖的增值芳香族化合物的唯一可行来源。这个综合项目将配位化学和有机方法论与​​我的专业知识相结合，为各种背景的高素质人员提供多学科和协作培训。