Direct tritium labeling of multifunctional compounds using organoiridium catalysis

• Published in: Journal of labelled compounds & radiopharmaceuticals Vol. 39; no. 4; pp. 291 - 298
• Main Authors: Chen, W., Garnes, K. T., Levinson, S. H., Saunders, D., Senderoff, S. G., Shu, A. Y. L., Villani, A. J., Heys, J. R.
• Format: Journal Article
• Language: English
• Published: Chichester John Wiley & Sons, Ltd 01-04-1997; Wiley
• Subjects: alkyl C-H; aryl C-H; C-H activation; Chemistry; deuterium exchange; Exact sciences and technology; exchange labeling; iridium catalysis; Organic chemistry; tritium exchange; Deuterium; Benzoxazole derivatives; Benzophenone derivatives; Catalytic reaction; Radiolabelling; Regioselectivity; Benzazepine derivatives; Isotope exchange; Benzene derivatives; Quinoline derivatives; Tritium; Transition metal Complexes; Hydrogen Isotopes; Iridium Complexes; Pyridine derivatives; Complexes Mixed; Benzamide derivatives; Platinoid Complexes; Chemical synthesis
• ISSN: 0362-4803; 1099-1344
• DOI: 10.1002/(SICI)1099-1344(199704)39:4<291::AID-JLCR973>3.0.CO;2-K

The tritium exchange labeling of a variety of complex compounds is achieved in the presence of catalyst precursor [(cod)Ir(PPh3)2]BF4 and limited amounts of tritium gas. The regioselectivity of exchange is high and consistent with empirical rules previously observed. High specific activity levels are often achieved, usually with specific aryl C‐H bonds. However, remarkably efficient exchange occurs in certain N‐alkyl groups. Studies of intermolecular inhibition of catalytic exchange suggest reasons why larger amounts of complex are sometimes required to label complex molecules; nevertheless, significant amounts of label incorporation into substrates can be achieved even starting with small amounts of labeling gas. © 1997 John Wiley & Sons, Ltd.