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The neighboring group effect of fluorine in the tritium labeling of organic substrates with [Cp*(PMe3)IrMe(CH2Cl2)]+[BArf]−, a cationic iridium(III) complex

2006; Wiley; Volume: 49; Issue: 7 Linguagem: Inglês

10.1002/jlcr.1072

1099-1344

Marc B. Skaddan, Robert G. Bergman,

Catalytic Cross-Coupling Reactions

The cationic Ir(III) complex, [Cp*(PMe3)IrMe(CH2Cl2)][BArf] (1, Cp*=η5-C5Me5, BArf=MeB(C6F5)3), has been shown to be a useful reagent in the tritium and deuterium labeling of organic substrates. During a recent reaction of 1 with a fluorinated molecule, we observed an unusually high incorporation of tritium ortho to the aromatic fluorines. To probe whether this was an isolated incident or a more general phenomenon, we have investigated the application of 1 towards the tritiation of simple fluorinated organic substrates. Our results indicate that aromatic fluorine indeed does exhibit a neighboring group effect in terms of directing ortho H/T exchange. The directing influence appears to be at least as strong as the hydroxyl moiety reported in previous works. Copyright © 2006 John Wiley & Sons, Ltd.