Oxidative Addition of Water to Ir(I) Complexes Bearing a Pincer-Type Silyl Ligand.

Reaction of water with in situ generated [(PSiP-R)Ir] (PSiP-R = [{2-(RP)CH}MeSi]; R = cyclohexyl, Bu or Pr) from [(PSiP-R)Ir(H)] and -butylethylene (tbe) showed high ligand dependency. Oxidative addition of water cleanly proceeded in the reaction of [(PSiP-Bu)Ir] in THF at room temperature to selectively afford a 16-electron hydrido-hydroxo complex [(PSiP- Bu)Ir(H)(OH)] almost quantitatively. In contrast, the reaction of cyclohexyl and Pr derivatives was unselective and formed various products containing Ir-H bonds. In the case of Pr-derivative, a small amount of 18-electron hydrido-hydroxo aqua complex [(PSiP-Pr)Ir(H)(OH)(HO)] was isolated and structurally characterized by X-ray crystallography.