Professor Jeffrey H. Byers, of the Department of Chemistry and Biochemistry at Middlebury College, is supported by a Research in Undergraduate Institutions award from the Organic and Macromolecular Chemistry Program for his studies of radical aromatic substitution via atom transfer addition. Professor Byers studies the reactions of aromatic and heteroaromatic substances with a variety of electrophilic radicals. The electronic nature of the aromatic ring is modified through the use of suitable protecting groups and through the formation of arene chromium tricarbonyl complexes, thus providing aromatic substrates reactive toward electron-rich radicals. Professor Byers is also exploring intramolecular reactions leading to the formation of mitocene and pyrrolizidine ring systems, common structural features of a range of biologically active compounds. Although organic molecules containing an unpaired electron (`radicals`) are often very reactive, they have until recently received comparatively little attention as potential participants in the synthesis of organic molecules. With the support of a Research in Undergraduate Institutions award from the Organic and Macromolecular Chemistry Program, Professor Jeffrey H. Byers, of the Department of Chemistry and Biochemistry at Middlebury College, explores a class of radical-forming reactions known as atom-transfer additions for their ability to facilitate the synthesis of aromatic compounds. Products potentially made accessible through the discovery and development of this chemistry include aryl acetic acids, a general class of compounds frequently used as analgesics and anti-inflammatory medications, as well as a variety of more complex structures representing common structural features of a range of biologically active compounds.