This grant in Organic and Macromolecular Chemistry provides support for the research of Dr. Peter Stang, University of Utah. The work is focused on preparing and understanding unusual bonding species in organic chemistry. The synthetic use of such species also will be studied. Three independent areas will be examined: a) unsaturated carbenes, b) organometallic chemistry and c) strained ring systems. The uses of silicon as a chiral auxiliary along with alkylidenecarbene-ylides will be studied. The detailed mechanism of metal-mediated unsaturated cross couplings will be examined using Pt as the metal and vinyl triflates as the substrates. The interaction of varied organometallic nucleophiles with alkynylvinyl triflates will also be probed. The chemistry of the new alkylidencycloproparenes with emphasis on oxidation, cycloadditions, and metal complexes will be developed along with the preparation of new, novel strained ring systems. Kinetics, stereochemistry, structure-reactivity, NMR, and X-ray structure determinations will be the major techniques and tools employed. Although these studies are primarily of a fundamental nature, they will provide considerable insight into the detailed mechanism of synthetically useful reactions. They will also provide a better understanding of organometallic pathways where fundamental mechanistic insights are currently limited and greatly needed.