Asymmetric Borenium Cations in Catalysis

医药、商品化工和农用化工领域的许多关键产品都是通过还原化学生产的手性化合物。这种材料的生产可以通过使用合适前体的常规化学计量还原，然后分离光学异构体来实现。这是一种非常低效的方法，因为它严重限制了所需光学纯材料的产量，并产生了大量必须处理的废物。另一种方法是对现成的前体进行不对称氢化，然而目前的技术依赖于昂贵的手性过渡金属催化剂，这些催化剂来自贵金属，如Pd、Rh或Ir。此外，产品中的残留金属对健康和环境具有重大影响，因此必须予以清除。这将进一步增加生产成本。在目前的提案中，我们将基于PI在2006年发现的受挫刘易斯对化学的创新概念，开发一种使用“无金属”催化剂技术的新策略。将这种方法用于高选择性不对称还原和催化还原，将提供一种新的高效策略，通过消除副产品废物，消除大量生产后净化的必要性，并利用更具成本效益的催化剂来降低生产成本。该项目将在女王大学和多伦多大学合作进行，并涉及多伦多Pirmal公司的工业合作者，Pirmal公司是一家在加拿大拥有重要研究机构的国际公司，专门从事定制合成。参与这项工作的学生将接受催化、有机和无机化学方面的培训，并获得新化学技术在工业应用方面的独特视角。

Many key products for the pharmaceutical, commodity chemical and agrochemical sectors are chiral compounds produced by reduction chemistry. The production of such materials can be achieved using conventional stoichiometric reductions of suitable precursors, followed by separation of optical isomers. This is a highly an inefficient approach as it severely limits the yield of the desired optically pure materials and generated significant quantities of waste that must be dealt with. An alternative approach is asymmetric hydrogenation of readily available precursors, however current technologies rely on expensive chiral transition metal catalysts derived from precious metals such as Pd, Rh, or Ir. Moreover, residual metals in the product are significant health and environmental concern and thus must be removed. This results in a further and substantial cost to production. In the present proposal, we will develop a new strategy that uses a "metal-free" catalyst technology based on the innovative concept of Frustrated Lewis Pair chemistry discovered by the PI in 2006. Adaptation of this approach for highly selective asymmetric and catalytic reductions will provide a new highly efficient strategy that will reduce cost of production by eliminating by-product waste, removing the necessity of extensive post-production purification and utilize more cost efficient catalysts. The project will be carried out collaboratively at Queen's University and the University of Toronto and involve an industrial collaborators from Pirmal Corporation in Toronto, an international company with a significant research presence in Canada specializing in custom synthesis. The students involved in this work will be trained in catalysis, organic and inorganic chemistry and also acquire a unique perspective on industrial applications of new chemical technologies.