Abstract
The cyclooctadienyliridium(I) dionates provide an alternative ortho-labelling approach to the more conventional iridium catalysts reviewed elsewhere in this special issue. The catalysts are utilized in DMF or DMA, removing potential problems of substrate insolubility in the solvents conventionally used for exchange labelling. Moreover, while readily prepared in a single step, the catalysts are also commercially available. In most cases recoveries are high, while the labelling achieved is both efficient and regiospecific. In addition, the reaction conditions are simple, requiring only conventional laboratory facilities and equipment.