Asymmetric Synthesis of Complex Molecules Using Polyfunctional Cyclopropanes

Texas Tech University, Lubbock TX

Investigators

Abstract

In this project funded by the Chemical Synthesis program of the Chemistry Division, Professor Andrew Harned is developing new synthetic methodologies based on the unusual reactivity displayed by a family of unique small molecules. In addition to exploring the reactivity of these small-molecule cyclopropanes, new catalysts are being developed to synthesize these materials as single stereoisomers. Several biologically active natural products are being synthesized using this methodology. In addition to these laboratory efforts, selected data from this work are being used to populate a web-based NMR FID database that is also under development in the PI's laboratory. This unique educational resource is being made available to instructors around the world. The chemical focus of the project concerns the development of new methodology for the efficient synthesis of complex molecules. The main goal is to harness the unusual reactivity patterns inherent to a family of highly functionalized, tricyclic cyclopropanes. Reacting these compounds with either nucleophiles or electrophiles affords highly functionalized, ring-opened products with high regio- and stereoselectivity. The requisite starting materials for the cyclopropanes, enantioenriched para-quinols, are synthesized with new chiral aryl iodide catalysts. Concurrent with these methodology studies, the unique cyclopropanes are being used as key intermediates for the construction of several natural products, specifically azaphilone lactones and briarane diterpenoids.