The synthesis of complex molecules found in natural systems places increasing demands on the synthetic organic chemist. The transition metals offer the fine chemical control needed for the development of new methods for a range of molecules found in medicine and agriculture. The overall objective of this grant in the Organic and Macromolecular Chemistry Program is to develop new synthetic methods using transition metal complexes to permit new modes of reactivity for organic functional groups. This will be achieved by careful study of the fundamental chemistry of the metal- organic species involved, to permit the development of useful, new synthetic transformations. The newly developed processes will be applied to the synthesis of complex molecules when possible. The scientific significance of the proposed research is that new chemical transformations of general use for organic synthesis will be developed, that new organic compounds with interesting physical, biological, and chemical properties will be produced. Thus beta-lactams will be synthesized by Pd(II) assisted aminocarbonylatin of olefins or vinyl carbamates. A variety of carbocyclic systems - including medium sized fused bicyclic systems will be synthesized from simple diene starting materials by an unusual "1,3" cycloaddition of electrophilic olefins and alkynes to pi-allylpalladium complexes followed by reductive elimination. A newly discovered photogeneration of aminoketenes and enaminoketenes from Group (VI) metal carbene complexes will be developed to provide an array of unusual organic compounds, including unnatural alpha-amino acids and peptides containing unnatural amino acids. These unusual metal-bound ketenes are expected to have broad utility in organic synthesis. Finally, new, practical, synthetic approaches to organometallic carbene and nitrene complexes will be developed and their utility in organic synthesis will be assessed.
