Bismuth nitrate catalyzed-michael reaction in water

ORGN 475

Bimal K. Banik, banik@panam.edu, Isabella Garcia, banik@panam.edu, and Dorothy Owens. Department of Chemistry, The University of Texas-Pan American, 1201 W. University Drive, Edinburg, TX 78541
Michael reaction is one of the most attractive methods in synthetic organic chemistry. Several Lewis and Bronsted acids have been utilized to accomplish this transformation. The main limitations of these processes are the use of organic solvents as the reaction media. These methods are not very environmentally friendly. Despite a huge success in this area, Michael reactions in water have not been explored systematically. Our own research on Lewis acid-catalyzed methods on indoles and carbamates has prompted to explore Michael reaction in water with various unstaturated carbonyl compounds. After a few experimentations, we have discovered that aqueous bismuth nitrate is a good reagent for this purpose. It is interesting to note that less nucleophilic carbamates can be used with success. A few other bismuth derived reagents and Bronsted acids have also been tested. It has been found that the success of this reaction depends on the concentration of the acid, nature of the acid and time of reaction. This project is supported through a HHMI grant.