Kinetic and thermodynamic preferences for the diastereoselective oxidative addition of H2 to trans-Ir(P*R3)2(CO)Cl: Monodentate chiral phosphines may impart exceptional degrees of diastereoselectivity

Article abstract of DOI:10.1021/ja026059i

Studies on square planar iridium complexes of the type trans-Ir(P*R₃)₂(CO)Cl, where P*R₃ is PhP[(C₅Me₄)]₂, PhP[Me₂C₄H₆], or PhP[Prⁱ₂C₄H₆], demonstrate that monodentate chiral phosphines impart exceptional degrees of diastereoselectivity in the oxidative addition of H₂. Thus, the oxidative addition of H₂ to the two faces of the meso isomer (R,S)-trans-Ir(P*R₃)₂(CO)Cl proceeds with a kinetic diastereoselectivity which exceeds that for related square planar iridium complexes employing bidentate chiral phosphine ligands. Furthermore, the kinetically favored dihydride is not favored thermodynamically, and the magnitude of the inversion of the kinetic and thermodynamic selectivities is greater than has previously been observed using bidentate phosphines. Copyright