Structure and stereochemistry of natural products

Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used analytical tools for natural products, synthesis, and catalysis research in chemistry. In the past decade, an array of novel NMR methods for complex molecules has been developed on the basis of anisotropic parameters. This opened up the possibility for studying the constitution, conformation, and configuration of challenging organic molecules with much higher precision and more rapidly than before. In our lab, we are interested in the development and application of residual dipolar coupling (RDC) and residual chemical shift anisotropy (RCSA) based NMR analysis for the determination of complete structures including stereochemistry of complex natural products. We developed gel-based and liquid crystalline phases as novel alignment media for polar organic solvents (e.g. Ge* and Sun* et al., Chem. Eur. J., 2012, Lei et al., JACS, 2014, Lei et al., Angew. Chem. Int. Ed., 2017). By employing those alignment media for measuring RDCs, we successfully determined the relative configuration of a number of natural products that could not be solved by other methods (e.g. Sun et al., JACS, 2011, Schmidt et al., JACS, 2012, Yang et al., JOC, 2019). Moreover, we are working on combining RDC and RCSA analysis with advanced computational techniques for determining the absolute configuration of chiral molecules.