Highly active iridium(I) complexes for catalytic hydrogen isotope exchange


William J. Kerr, w.kerr@strath.ac.uk1, Stephanie Irvine, s.irvine@strath.ac.uk1, Jack A. Brown1, Shalini Andersson2, and Goran N. Nilsson2. (1) Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom, (2) Medicinal Chemistry, AstraZeneca, R&D Molndal, SE-431 83 Molndal, Sweden
Hydrogen isotope exchange represents an effective way of following the metabolic pathways of potential drug candidates and, therefore, is of increasing importance to the pharmaceutical industry. With this in mind, the ideal situation would be to utilise catalytic quantities of a transition metal species to carry out this transformation on a functionalised compound. To this end, a number of iridium catalysts have been developed and applied to this process with varying success. Traditionally, the most effective catalyst used in this field is Crabtree's catalyst 1. However, often super-stoichiometric amounts of this species are required together with long reaction times. This presentation reveals a series of novel iridium(I) complexes of type 2, and highlights their considerable efficiency and general applicability in the field of hydrogen isotope exchange, with levels as low as only 0.5 mol% catalyst loading over short reaction times being required to deliver extremely high levels of labelling.