New Approaches for Seletivity in the Synthesis of Organic Compounds (Chemistry)

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This program is being supported by the Organic and Macromolecular Chemistry Program. The goal of the work is to meet the increasing demand for efficient synthetic approaches to complex organic molecules of theoretical and biological interest. New tools in the form of new reactions and reagents will result from this work. Four diverse areas cover a broad scope of endeavor. A major effort asks the question of whether simple molecular entities in the form of transition metal complexes can serve as catalysts for selective organic transformations in a fashion analogous to what enzymes do for the living cell. Manipulation of allyl systems for chemo-, regio-, diastereo-, and enantioselective transformations will involve exploring designed complexes embracing Pd, Mo, and W. Intramolecular carbametallation of unsaturated functional groups represents a new exciting thrust for ring construction. Such reactions involving molecular change by isomerization enters an era of designing reactions for minimizing chemical waste and therefore minimizing disposal. Another development envisions a general cycloaddition approach to odd membered rings in contrast to the extremely import Diels-Alder reaction. Bifunctional reagents which do not self-annihilate but may be activated by transition metal templates provide the basis for such a development. Unexpected reactvity of organosulfur compounds provides a unique opportunity for multifaceted reactivity. These reagents become "chemical chameleons" since they can totally interconvert between two opposing types of reactivity depending upon their environment. They also offer a unique approach for asymmetric synthesis. The final section deals with the concept of designing composite functional groups or "pseudofunctional groups" based upon a partnership of strain and reactivity.