DEVELOPING AN UNDERSTANDING OF ASYMMETRIC INDUCTION

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This proposal is directed toward the understanding of the mechanisms of catalytic asymmetric processes and the design and development of chiral transition metal based catalysts to be used in asymmetric catalysis. The impacts of chiral synthetic technology are quite diverse and are critical to the fields of medicinal chemistry and pharmaceutical chemistry. The specific aims of this proposal are: (I) To understand the structure, properties and reactivity of chiral bissulfonamido complexes and their role in asymmetric catalysis, (II) To synthesize (bissulfonamido)TiX2 complexes (X=F, C1, Br) and their base adducts, (III) To explore the synthesis, structure and reactivity of bissulfonamido titanium bisamide complexes which are versatile intermediates for the preparation of (bissulfonamido)titanium species, and (VI) to develop hexadentate titanium bissulfonamide compounds and apply them to asymmetric catalysis. Our long-term objective is to develop an understanding of the mechanism of chirality transfer in established asymmetric processes in order to build a foundation for the rational design of new asymmetric reactions. The course of asymmetric synthesis has been driven by an increase in the demand for optically pure materials. As result, much of the focus of this field has turned to improving methods to screen catalysts in asymmetric processes. However, rarely is the catalytic system understood and often little is known of the structure or the operation of the catalyst. The methods that we use to accomplish our goals involve the independent synthesis of proposed catalysts in asymmetric reactions and their characterization (including structurally). These complexes are then tested in the asymmetric process to evaluate their viability as catalysts.