Diastereoselective Synthesis of Chiral Octahedral Iridium(III) Phosphano–Oxazoline Complexes

Reaction of the dimer [Ir­(μ-Cl)­(η2-coe)2]2 (coe = cyclooctene) with chiral phosphano–oxazoline ligands (PN*) renders neutral mononuclear iridium­(I) complexes of the formula [IrCl­(η2-coe)­(PN*)] (1, 2), which in turn are oxidized to the corresponding iridium­(III) hydride species [IrCl2H­(η2-coe)­(PN*)] (3, 4) by treatment with aqueous HCl. The latter react with diphosphanes (PP) in the presence of NaSbF6 to afford cationic complexes of stoichiometry [IrClH­(PN*)­(PP)]­[SbF6] (5–16). The fluorophenyldiphosphane-containing compounds [IrClH­(PN*)­(dfppe)]­[SbF6] (15, 16) evolve to the corresponding Ir­(I) species [Ir­(PN*)­(dfppe)]­[SbF6] (17, 18) by HCl loss. The new compounds have been fully characterized by analytical and spectroscopic means, including the molecular structure determination of [IrCl2H­(η2-coe)­(PNInd)] (3), [IrClH­(PNInd)­(dppen)]­[SbF6] (6a,b), [IrClH­(PNInd)­(dppp)]­[SbF6] (7a), [IrClH­(PNiPr)­(dppp)]­[SbF6] (13a), [IrClH­(PNInd)­(dfppe)]­[SbF6] (15), [Ir­(PNInd)­(dfppe)]­[SbF6] (17), and [Ir­(PNiPr)­(dfppe)]­[SbF6] (18) by X-ray diffractometric methods.