Research Interests
Dr. Thomas Junk
We are investigating chemical reactions under extreme (non-classical) conditions, as they exist in supercritical aqueous and ultrasonicated media. Chemical processes that occur under these conditions are relevant to a wide range of disciplines, including environmentally benign production, chemical waste remediation, and the development of novel synthetic access routes to specialty chemicals.
Near-critical and supercritical aqueous conditions are of growing interest in synthetic chemistry. Despite the high temperatures involved, we found many organic substrates to be surprisingly stable in supercritical aqueous media. Reactions which cannot be realized using "classical" approaches occur readily, including the deprotonation/reprotonation of hydrocarbons in aqueous phase (eq. 2 and 3) and regioselective halogen exchange reactions (eq. 4). Reductive dehalogenations with formic acid (e.g. eq. 5) do proceed without catalysts under these conditions. The synthesis of deuterated compounds as shown in eq. 2 and 3 typically requires 10-100 minutes and is difficult to achieve by conventional methods.
We are interested in the synthesis and characterization of novel heterocycles containing tellurium. Organotellurium compounds have shown promise as low temperature superconductors, selective reagents, as arachnicides and as additives to photographic emulsions, but methods of acess remain limited. Currently, we are developing novel preparations to tellurazoles and tellurazines based on boronic acid intermediates, and via selective ortho nitration of aryltellurinic acids.