NEW SYNTHETIC METHODS USING HIGHLY REACTIVE METALS

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The overall objective of this proposal is the development of new synthetic methodologies using highly reactive metal powders. Several new approaches for the preparation of highly reactive metal powders have been developed in our laboratories. These metal powders exhibit far superior reactivity towards oxidative addition reactions than any described for these metals in the literature. Using these metals, a wide variety of new reactions and dramatic extensions of existing reactions are proposed. The metal to be studied include Ni, Cd, Zn, U, Fe, Mg, and Cu. While this study will not be directed towards the synthesis of any one natural product, it is anticipated that the results of this study will be of great value to the synthetic community. Requests from synthetic chemists from all over the USA and the world are constantly coming to our laboratories regarding preparation and use of highly reactive metals developed in our laboratories. The new chemistry proposed in this grant request will provide for several new significant synthetic approaches. The highly reactive magnesium studies should yield valuable extensions of Grignard chemistry. Moreover, the facile generation of a five-membered magnesium metallocycle should prove to be of extensive value. New cyclization reactions using nickel, copper, and magnesium are proposed which will tolerate a wide range of functionality. The ability to generate organocadmium reagents and organocopper reagents directly from alkyl and aryl halides with most any functionality will dramatically increase the utility of these very versatile reagents. A new exciting class of metal-lithium alloys is proposed; one of these may be an entry into highly reactive lithium. Highly reactive zinc is expected to allow the preparation of substituted cyclopropanes in the Simmons-Smith reaction. Also, the direct preparation of dialkyl zinc reagents with a wide variety of functional groups present is most probable. Several new classes of zero valent complexes of Ni and Fe are proposed. The preparation of several new organoiron species are proposed and several cross-coupling reactions with these reagents are suggested. The highly reactive uranium will be used to carry out reductive coupling reactions as well as to generate new organouranium species. The synthetic utility of these new organometallic species will be examined. Finally, this study will provide insight into the origin of high reactivity at a metal surface as well as mechanistic considerations regarding oxidative addition reactions at a metal surface.