Developing New Reactions and Catalysis via Designer Ligands for Organometallic Chemistry

我的研究项目结合了化学合成、催化和聚合，以解决与社会相关的有意义的基础和应用问题。更具体地说，我的研究的主要目标是制备新的和不寻常的含金属分子，以催化合成药物、农用化学品、重要的化学中间体、精细化学品和材料。从教学的角度来看，非常重视学习必要的实验室技术，发展批判性思维和沟通技能，以及以安全和深思熟虑的方式工作的能力。在接下来的5年里，我的研究团队将合成由设计的NNN-钳形配体稳定的晚期过渡金属配合物。这些物种被认为是反应性14电子、T型中间体的潜在来源，可以从这些中间体中预见到广泛的催化途径。初步工作表明，半疏水基膦亚胺供体与金属中心协同作用，激活包括H2、CO和硅烷在内的各种小分子。将对这些反应的产物进行研究，以确定它们在调节一系列催化过程中的能力。例如，我们的Rh硅烯(LRH=SiR 2)中的硅原子预计会定位底物，以促进具有挑战性的键的激活，如C-F。将氟安装到有机分子中对制药工业非常重要，因为超过30%的新药含有氟。还将制备与Rh和Ge、TiN和B之间具有多个键的相关络合物，并对其反应化学进行深入探讨。我实验室的另一个方向将集中在磷氮化物(R3P-(N3)-R)配体及其金属配合物的制备上。由于磷氮化物容易失去氮气，它们的配位化学在很大程度上还没有被认识到。然而，侧基易于微调，它们的配位多功能性，以及转化为磷酰亚胺的能力，表明磷氮化物在无机化学和均相催化中提供了潜在的配体。我们将开发稳定的途径，从而更容易地研究含有磷氮化物的配体。鉴于f元素倾向于适应高配位数，它们将用于初步络合研究。总而言之，这项工作在解决加拿大目前面临的问题(例如将大气中的氮气转化为农产品、抗击疾病的新药物)以及开发将改善加拿大人生活的新技术方面具有巨大潜力。例如，创造直接安装碳、硅和氟的方法是获得有价值的有机分子的有效和成本效益高的途径。最终，这种化学将提供新的催化系统，并为下一代科学家提供有价值的培训。

My research program combines chemical synthesis, catalysis and polymerization to tackle meaningful fundamental and applied questions that are relevant to society. More specifically, the primary goal of my research is to prepare new and unusual metal-containing molecules to catalyze the synthesis of pharmaceuticals, agrochemicals, important chemical intermediates, fine chemicals and materials. From a pedagogical perspective, great emphasis is placed upon learning requisite laboratory techniques, the development of critical thinking and communication skills, and the ability to work in a safe and thoughtful manner. Over the next 5 years my research team will synthesize late transition metal complexes that are stabilized by designer NNN-pincer ligands. These species have been targeted as potential sources of reactive 14-electron, T-shaped intermediates, from which a wide range of catalytic pathways can be envisioned. Preliminary work has revealed that the hemilabile phosphinimine donors act cooperatively with the metal centre to activate various small molecules, including H2, CO and silanes. The products of these reactions will be studied to ascertain their competence in mediating a range of catalytic processes. For example, the silicon atom in our rhodium silylenes (LRh=SiR2) is expected to position substrates to facilitate the activation of challenging bonds, such as C-F. Installation of fluorine into organic molecules is important to the pharmaceutical industry as upwards of 30% of new drugs contain fluorine. Related complexes that bear multiple bonds between rhodium and germanium, tin and boron will also be prepared and their reaction chemistry explored in depth. Another direction in my laboratory will focus upon the preparation of phosphazide (R3P-(N3)-R) ligands, and metal complexes thereof. Because phosphazides are prone to loss of N2, their coordination chemistry is largely unrealized. However, the ease with which pendant groups can be fine-tuned, their coordinative versatility, and the ability for conversion to phosphinimines, suggests that phosphazides offer potential as ligands in inorganic chemistry and homogeneous catalysis. We will develop routes to stable, and thus, more easily studied phosphazide-containing ligands. Given the tendency of f-elements to accommodate high coordination numbers, they will be used for initial complexation studies.    In summary, this work has great potential for addressing issues currently confronting Canada (e.g. conversion of atmospheric N2 into agricultural products, new pharmaceuticals to combat disease), and developing new technologies that will improve the lives of Canadians. For example, the creation of methods for the direct installation of carbon, silicon and fluorine represents an efficient and cost-effective route to valuable organic molecules. Ultimately, this chemistry will afford new catalytic systems and provide valuable training to the next generation of scientists.