With the support of the Organic and Macromolecular Chemistry Program, Professor W. Dean Harman, of the Department of Chemistry at the University of Virginia, is studying organic transformations using eta-2 arene complexes of rhenium. Through the selective and reversible binding of arenes or polyaromatic hydrocarbons through dihapto coordination to a transition metal, their reactivity toward electrophiles is enhanced. Reactive intermediates (e.g., arenium and allyl cations) are stabilized, facilitating the assembly of polycyclic structures. In addition, metal coordination directs the stereochemistry of various chemical transformations and protects the coordination site for additional transformations. While dihapto coordination of arenes has previously been limited to pentaammineosmium(II) complexes, Professor Harman is developing a new class of rhenium(I)-based dearomatization agents.
Aromatic compounds (e.g., benzene, toluene) represent one of the most readily available classes of compounds for elaboration into more complex molecular structures. However, their unique properties place some limitations on the chemical reactions available for their elaboration. Professor W. Dean Harman, of the Department of Chemistry at the University of Virginia, with the support of the Organic and Macromolecular Chemistry Program, is developing unique metal-based reagents which allow for the dramatic alteration of the reactivity of aromatic compounds. Through his studies, new methods are being developed allowing the facile and selective conversion of these readily available starting materials to compounds of potential significance in their own right or as intermediates in the synthesis of pharmaceuticals and other fine chemical products.
