The neighboring group effect of fluorine in the tritium labeling of organic substrates with [Cp*(PMe 3 )IrMe(CH 2 Cl 2 )] + [BAr f ] − , a cationic iridium(III) complex

The cationic Ir(III) complex, [Cp*(PMe 3 )IrMe(CH 2 Cl 2 )][BAr f ] ( 1 , Cp*=η 5 ‐C 5 Me 5 , BAr f =MeB(C 6 F 5 ) 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.