New Lewis Bases for Chemical Catalysis

新的化学催化刘易斯碱化学部的化学合成计划支持卡尔Scheidt教授的项目。Scheidt教授是西北大学化学系的教员。他正在开发新的化学催化剂。化学催化剂可以有效和可持续地合成新的小分子和材料，这对制药，材料科学和生物医学研究界非常重要。由于它们在这些领域中的实用性，衍生自刘易斯碱（能够提供电子对的分子），特别是N-杂环卡宾（NHC）的催化剂特别令人感兴趣，并且使用这些系统的工作在过去十年中已经爆炸。在这种努力中，NHC经常被用作配体以产生手性金属络合物以及在不存在过渡金属的情况下本身作为催化剂（无金属或有机催化）。然而，尽管有这些努力，人们对如何调整NHC基催化剂以优化其在新反应中的性能知之甚少。因此，Scheidt小组正在探索一种新型的NHC-过渡金属络合物作为催化剂。这些新系统可用于系统地研究结构变化如何改变NHC的性质和催化行为。这项工作对未来如何设计NHC家族中的新催化剂具有广泛的影响。该项目位于有机，不对称合成和催化的交叉点，因此非常适合跨学科科学的培训和教育。就项目的广泛影响而言，Scheidt博士积极参与外展活动，重点关注STEM领域代表性不足的群体招募。社会的可持续性和进步依赖于基于分子科学的新发现。其中一个发现是新的富电子分子（刘易斯碱）作为广泛反应的催化剂的普遍用途，其中许多反应对材料、生物学和药理学工作都有影响。在正在进行的具体工作中，Scheidt博士正在使用一种新的N-杂环卡宾（NHC）-金属络合物家族来催化新的不对称键形成反应，并为如何调整NHC催化剂的亲核性提供新的机理见解。为这项工作选择的特定合成目标是α-硼基胺。由于目前可用于α-硼基化反应的方法存在主要限制，这些限制阻碍了将所选择的靶标用作合成结构单元，因此选择α-硼基胺作为靶标很好地突出了正在开发的催化剂的广泛合成意义。所获得的机理见解集中在提高我们对刘易斯碱和过渡金属催化的认识，并确定支配催化剂行为的结构-反应性关系。Scheidt博士的外展活动建立在他的研究基础上，目标是改善西北大学化学博士课程中代表性不足的群体的招聘。

New Lewis Bases for Chemical CatalysisThe Chemical Synthesis Program of the Chemistry Division supports the project by Professor Karl Scheidt. Professor Scheidt is a faculty member in the Department of Chemistry at Northwestern University. He is developing new classes of chemical catalysts. Chemical catalysts enable the efficient and sustainable synthesis of new small molecules and materials that are important for pharmaceutical, material science, and biomedical research communities. Because of their utility in these areas, catalysts derived from Lewis bases (molecules capable of donating an electron pair), and in particular N-heterocyclic carbenes (NHCs), have been of particular interest, and work with these systems has exploded during the last decade. In this effort, NHCs have frequently been employed as ligands to generate chiral metal complexes as well as catalysts in their own right in the absence of a transition metal (metal free or organocatalysis). Yet in spite of this effort, little is known about how NHC-based catalysts can be tuned in order to optimize their performance in new classes of reactions. For this reason, the Scheidt group is exploring a novel family of NHC-transition metal complexes as catalysts. These new systems can be used to systematically study how changes in structure alter the properties and catalytic behavior of the NHC. The work has broad implications for how new catalysts in the NHC-family will be designed in the future. The project lies at the intersection of organic, asymmetric synthesis, and catalysis and thus is excellent for training and education in interdisciplinary science. In terms of broader impacts of the project, Dr. Scheidt is actively engaged in outreach activities focused on underrepresented group recruitment into the STEM fields.The sustainability and advancement of society relies on new discoveries based on molecular science. One such discovery is the general utility of new electron-rich molecules (Lewis bases) as catalysts for a broad range of reactions, many of which have implications for materials, biological, and pharmacological efforts. In the specific work being pursued, Dr. Scheidt is using a novel family of N-heterocyclic carbine (NHC)-metal complexes to both catalyze new asymmetric bond forming reactions and to provide new mechanistic insights into how the nucleophilicity of an NHC-catalyst can be tuned. The specific synthetic targets selected for the effort are alpha-boryl amines. Since there are major limitations to the currently available methods for alpha-borylation reactions that have hampered the use of the chosen targets as synthetic building blocks, the choice of the alpha boryl amines as targets nicely highlights the broad synthetic implications of the catalysts being developed. The mechanistic insights being gained center on advancing our knowledge of Lewis base and transition metal catalysis and determining the structure-reactivity relationships that govern catalyst behavior. Dr. Scheidt's outreach activities build on his research and target the improved recruitment of underrepresented groups into the chemistry doctoral program at Northwestern University.