C–H Activation with Iridium(III) and Rhodium(III) Alkyl Complexes Containing a 2,2′‐Bipyridyl Ligand

Heating [Rh(dtbpy)(κ 2 ‐ C,C′ ‐CH 2 CMe 2 C 6 H 4 )(CH 2 CMe 2 Ph)] ( 1 ; dtbpy = 4,4′‐di‐ tert ‐butyl‐2,2′‐bipyridyl) in p ‐xylene at 110 °C resulted in the formation of the 2‐ tert ‐butylphenyl complex [Rh(dtbpy)(κ 2 ‐ C,C′ ‐CH 2 CMe 2 C 6 H 4 )(C 6 H 4 t Bu‐2)] ( 3 ). Treatment of complex 1 with diethyl phosphite gave the phosphito‐bridged dimer [Rh(dtbpy)(κ 2 ‐ C,C′ ‐CH 2 CMe 2 C 6 H 4 ){P(O)(OEt) 2 }] 2 ( 4 ). Refluxing [Ir(dtbpy)(κ 2 ‐ C,C′ ‐CH 2 CMe 2 C 6 H 4 )(C 6 H 4 t Bu‐2)] ( 2 ) with 2‐phenylpyridine (ppyH) and 4‐(2‐pyridyl)benzaldehyde in toluene followed by column chromatography afforded [Ir(dtbpy)(CH 2 CMe 2 Ph)Cl(κ 2 ‐ N , C ‐ppy)] ( 5 ) and the carbonyl complex [Ir(dtbpy)(CH 2 CMe 2 Ph)(CO)(R)] ( 6 ) [R = 4‐(2‐pyridyl)phenyl], respectively. Anion metathesis of [M(dtbpy)(CH 2 CMe 2 Ph)(H 2 O)(OTs) 2 ] with NaBAr F 4 [Ar F = 3,5‐(CF 3 ) 2 C 6 H 3 ] afforded cationic [M(dtbpy)(CH 2 CMe 2 Ph)(H 2 O)(μ‐OTs)] 2 [BAr F 4 ] 2 [M = Rh ( 7 ), Ir ( 8 )] that are capable of catalyzing H/D exchange of tetrahydrofuran by using D 2 O as the deuterium source. The crystal structures of complexes 4 – 7 were determined.