| Project Description: Performing large-scale organic reactions efficiently has always been of interest to the pharmaceutical industry. Recently, efforts have been made to replace conventional heating methods with microwave irradiation because solutions are heated more effectively in the microwave. The Wittig reaction is one of the most common tools used by synthetic chemists for carbon-carbon bond formation. It has been the key step in the preparation of a variety of drugs such as the hormone, prostaglandin F2?, and the anti-cancer agent, calicheamicin.1,2
Using conventional heating, the Wittig reaction predictably forms a mixture of cis- and trans-alkenes, with the trans-product being favored. However, Barros et al. have reported that this selectivity can erode in the microwave reactor.3 This may mean that microwave irradiation is changing the relative rate of the two competing reactions. I propose to study the kinetic effect of this reaction in the microwave using a variety of solvents. Understanding this reaction more clearly will shed new light on the debate over how microwaves affect the mechanisms of organic reactions.
1. Corey, E. J. and others J. Am. Chem. Soc. 1969, 10, 320.
2. Nicolau, K. C. and others J. Am. Chem. Soc. 1992, 114, 10082.
3. Barros, M. T. and others Eur. J. Org. Chem. 2007, 3655. |
