Studies on the Use of Cationic Iridium(III) Complexes in Lewis Acid-Catalyzed C-C Bond-Forming Reactions

University Of Rochester, Rochester NY

Investigators

Abstract

In this project, the catalytic behavior of cationic octahedral iridium(III) d6 complexes will be studied for C-C bond formation in reactions principally involving the Nazarov cyclization. The kinetics and mechanism of Nazarov cyclization catalyzed by cationic Ir(III) complexes having adjacent labile binding sites will be studied, including a detailed examination of substrate binding coupled with targeted substrate variation to probe Lewis acidity and ligand modification to assess electronic and steric effects on catalyst effectiveness. The Ir(III) complexes will be exploited as catalysts for tandem or cascade reaction sequences initiated with Nazarov cyclization to create complex carbocyclic systems with multiple stereocenters in single pot procedures. Chiral Ir(III) catalysts with labile adjacent sites will be developed for both asymmetric Nazarov cyclization and tandem reactions. With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Richard Eisenberg and Dr. Alison J. Frontier, of the Department of Chemistry at the University of Rochester. In the development of synthetic methods for the construction of complex organic molecules including natural products and pharmaceutically active compounds, catalysis remains at the forefront. This project represents a new collaboration between an inorganic chemist whose main research focus has been on bond activation and catalysis using platinum group elements and an organic chemist whose research program extends from synthetic methodology development using organometallic compounds to the total synthesis of natural products. Drs. Eisenberg and Frontier will explore the fundamental mechanisms by which particular iridium-catalyzed reactions proceed, with the resulting information allowing them to develop more highly controlled reactions. These studies will in turn permit the development of new synthetic methodologies applicable to the synthesis of commodity and fine chemicals.