This proposal details a plan for the development of diaryliodonium salts as a versatile reagent class for bioconjugation (click) chemistry. Iodonium salts have a number of desirable properties: they are simple to make and stable to air and moisture, yet display a diverse array of reactivity patterns. If these reactivity patterns can be adapted to tolerate biologically relevant systems, then they would be a valuable addition to the bioconjugation compendium. This proposal outlines the first steps that will be taken to realize this goal through the achievement of three main objectives. The first objective is to design and synthesize a series of iodonium salts that contain a “clickable” handle to allow them to be derivatized with a biomolecule. The second objective involves the development of a Pd-catalyzed Heck reaction with these iodonium salts that is tolerant of biological functionality. The third objective is to display the utility of this new bioconjugation reaction. To that end, the bio-Heck reaction will be used in the synthesis of multifunctional protein nucleic acids for applications in multivalent display and pretargeted drug delivery. The proposal also calls for the collaboration with the Professor Jason Chin, with whom we will develop a method for site-selective protein modification using the bio-Heck reaction. This project is designed with the intention of facilitating international transfer of knowledge, both from the researcher to the Host, but also through the development of international scientific dialogue between the Host organization and researcher’s home country.