Synthesis, Molecular Structure, and Reactivity of Indenylrhodium Complexes Containing Diphenylcarbene as Ligand^†

(η⁵-Indenyl)rhodium(I) complexes of the general composition [(η⁵-C₉H₇)Rh(CPh₂)(L)] (L = SbiPr₃ (6), PiPr₃ (7), PPh₃ (8), PiPrPh₂ (9), PiPr₂Ph (10)) were prepared from the square-planar precursors trans-[RhCl(CPh₂)(L)₂] (1−5) and C₉H₇K in THF. Treatment of 6−10 with carbon monoxide resulted in an unusual migratory insertion of the carbene ligand into one of the C−H bonds of the five-membered ring of the indenyl unit to give the compounds [{η⁵-C₉H₆(CHPh₂)}Rh(CO)(L)] (12−16) in 78−87% yield. The X-ray crystal structure analyses of 6 and 13 revealed that in both complexes the slip distortion from a η⁵ to a η³ coordination mode of the indenyl ligand is nearly the same, independent of the bulky CHPh₂ group in the ring-substituted species.