Harnessing Nonclassical Metal-Arene Interactions to Achieve Enantioselective Catalysis

点击翻译按钮获取中文摘要

The Chemical Catalysis Program in the Chemistry Division at the National Science Foundation supports Professor LeGrande M. Slaughter of the University of North Texas, for studies aimed at utilizing nonclassical interactions of metals with aromatic groups on chiral ligands to achieve enantioselective catalysis. These poorly-understood secondary interactions could augment the steric interactions typically employed in chiral catalyst design, potentially leading to highly enantioselective reactions that are not achievable with conventional chiral ligands. The research will use a set of new chiral binaphthyl synthons to create chiral acyclic diaminocarbene and phosphinite ligands that are optimized to support metal-arene interactions. The ability of these interactions to promote synthetically useful enantioselective reactions, including hydrofunctionalizations of carbon-carbon multiple bonds, asymmetric carbon-carbon couplings, and electrocyclizations, will be investigated. Structural, spectroscopic, and computational studies will probe the nature of weak metal-arene interactions and their role in catalysis, focusing on the catalytically important metals palladium and gold. New catalytic methods for the synthesis of chiral, medicinally important complex molecules from inexpensive achiral precursors are an expected outcome of this research. The ability to synthesize chiral molecules in enantiomerically pure form is important, because the two enantiomers or 'mirror images' of a drug molecule can have very different effects on the human body. This research could provide new tools to prepare complex molecules as pure single enantiomers, potentially providing significant benefits to society in the form of new chiral drug precursors. These studies will be closely tied to an outreach program entitled 'The Magic of Catalysts' that will use hands-on experimentation to introduce middle school students to concepts of research and science using catalysis as a focus. Schools with high percentages of Native American students will be targeted with the help of established collaborators in public education, with a goal of broadening participation of Native Americans in activities that could lead to attainment of higher education and careers in science. The development of metal-arene interactions as a novel motif for achieving enantioselective catalysis could have a transformative impact on technologies for the synthesis of useful molecules by stimulating further study of the little-investigated role of secondary interactions in transition metal catalysis.