Applications of Bismuth Compounds As Catalysts in Organic Synthesis

Illinois Wesleyan University, Bloomington IL

Investigators

Abstract

This project focuses on the development of new applications of bismuth compounds, including asymmetric synthesis using bismuth catalysts. Specific objectives include developing multicomponent allylation reactions of dioxolanes, carrying out protection-deprotection chemistry under mild conditions using bismuth iodide, catalyzing cycloaddition reactions - including the synthesis of tetrahydroquinolines and pyridones via aza Diels Alder reactions - with bismuth salts, and the development of new bismuth salts as catalysts. With the support of this RUI award from the Organic and Macromolecular Chemistry Program, Professor Ram Mohan, of the Department of Chemistry at Illinois Wesleyan University, is studying the use of bismuth compounds as environmentally-friendly catalysts in organic synthesis. The biochemistry, toxicology and environmental effects of bismuth compounds have been well documented. The majority of bismuth compounds are relatively non-toxic (e.g., the LD50 (g/kg) of BiOCl is 22 and that of Bi2O3 is 5; compared with a LD50 of 3.75 for NaCl). Bismuth and several of its compounds are commercially available and are relatively inexpensive, and they are insensitive to small amounts of air and moisture, thus eliminating the need for anhydrous solvents. Many of the reactions catalyzed by bismuth compounds can also be done in relatively non-toxic solvent systems (such as acetone/water). In addition, the highly catalytic nature of several bismuth compounds makes these procedures amenable to large-scale synthesis. The development of green catalysts should be of significant interest to all practicing synthetic chemists and of particular interest to pharmaceutical process industry.