This dissertation describes the development of several novel chemical reactions employing allyl and alkenyl zirconocenes. These diverse nucleophiles were employed in the synthesis of a variety of biologically and chemically important molecules. Initially, allyl zirconocenes were employed for the addition to imines, thereby providing rapid access to functionalized homoallylic amines. We were later able to employ alkenyl zirconocenes in both the construction of C-glycosidic bonds and the addition to chiral imines. The power of these transformations was realized by a rapid and stereoselective synthesis of an immunostimulant agent and its analogs. Biological evaluation of these compounds showed encouraging activity against malaria. Small molecule radioprotectant agents have also been developed and show promising potential for therapeutic use. Finally, we were able to install key stereocenters of the Stemona alkaloid tuberostemonone.