New Approaches for Efficiency in Synthetic Organic Chemistry

Stanford University, Stanford CA

Investigators

Abstract

Among the most demanding challenges in organic chemistry is the introduction of chirality via catalytic methods. This project examines new concepts towards this goal in four disparate areas. The first involves the rational design of ligands for formation of dinuclear and heterodinuclear metal complexes as catalysts for addition reactions. The second area involves asymmetric trimethylenemethane (TMM) cycloadditions. The fact that the addition of the acceptor occurs on the face of the TMM unit distal to where the metal and its attendant ligands reside makes asymmetric induction highly challenging. With the aid of molecular modeling, new ligand families have been designed for [3+2], [3+4], and [3+6] cycloadditions. The third section examines Pd and Mo catalyzed asymmetric allylic alkylation. Using ligand design, contrasteric nucleophilic addition to the more substituted allyl terminus as well as contrathermodynamic addition to the C-2 position of the allyl unit will be attempted. Novel Ru-Pd sequential reactions for asymmetric synthesis will also be studied. The fourth area is the asymmetric induction in Ru catalyzed reactions for their exploration in alkene-alkyne coupling and allylic alkylations. With this award, the Organic and Macromolecular Chemistry Program supports the research program of Professor Barry M. Trost of the Department of Chemistry at Stanford University. Professor Trost's program revolves around the theme of enhancing synthetic efficiency by inventing new catalytic processes that exercise enhanced chemo-, regio-, diastereo-, and enantio-selectivity. Particular attention focuses on processes that enhance atom economy, a key aspect of "green chemistry". Success has impacts on areas ranging from materials science to biology, especially with respect to the pharmaceutical and agrichemical industries.