Synthetic and Mechanistic Studies of Organometallic Reagents

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

With the support of the Organic Dynamics Program in the Chemistry Division, Professors Hans J. Reich at the University of Wisconsin-Madison will continue fundamental studies on several projects involving main group organometallic compounds. Organolithium reagents are widely used for forming carbon-carbon bonds. They are also useful for forming carbon-X bonds, and thus are common precursors to many other organometallic reagents (B, Zn, Ti, Al, Cu, Ce, Sn, Si, P, S, Se to name a few) with important uses in synthetic chemistry. The goal of the research is a mechanistic understanding of important organometallic reactions. More than perhaps any other class of organometallic compound, the chemical properties of organolithium reagents are dominated by inter - and intramolecular interactions with solvents and basic pendant groups, as well as by aggregation phenomena. The proposed spectroscopic and reactivity studies of solvation and chelation together with product, selectivity and rate studies will result in a better understanding of these phenomena, better predictability of the chemical reactions of organolithium reagents, and expansion of the applications of lithium reagents. A rapid injection NMR apparatus developed during the previous grant period is now functional and will be used to examine the reactivity of individual aggregates of lithium reagents and the individual conformations (carbonyl E/Z) of electrophiles such as esters, thioesters, and amides. The Organic and Macromolecular Chemistry Program supports Professors Hans J. Reich at the University of Wisconsin-Madison who will provide mechanistic insight into some chemical reactions and chemical species of great importance to the design of procedures in synthetic organic chemistry. The work supported by this grant will also provide a broad background in physical organic chemistry, organometallic chemistry, spectroscopy, and organic synthesis to graduate and undergraduate researchers. Professor Reich has developed and will continue to provide to the scientific community free computer programs useful for NMR simulations (WINDNMR-Pro) and for graphics and chemical structure drawing (WINPLT). The program produces drawings that can be converted into web pages or used directly in presentations. There are about 500 registered users of the WINPLT program. He will continue to maintain a website that is a reference source for the chemical community to aid in predictions of all types of molecular behavior that are affected by acidity. The website has had over 100,000 visitors since its opening in 2001, and currently has about 1800 visitors a week.