Oxidative access via aqua regia to an electrophilic, mesoionic dicobaltoceniumyltriazolylidene gold(III) catalyst

A gold(III) complex with the hitherto most electron poor mesoionic carbene ligand is presented. Aqua regia was the oxidizing agent of choice for the synthesis of this unusual organometallic compound. The Au(III) complex is redox-rich, and also acts as a catalyst for oxazole formation, delivering selectively a completely different isomer compared to its Au(I) congener.