Multiple Carbon–Carbon and Carbon–Metal Bond Formation from an Iridium-pybox Complex and Electron-Poor Terminal Alkynes: Synthesis of Iridium Complexes with a Novel κ⁴N,N,N,C Tetradentate Ligand

The reaction of the complex [Ir­(η²-C₂H₄)­{κ³<i>N</i>,<i>N</i>,<i>N</i>-(<i>S</i>,<i>S</i>)-^<i>i</i>Pr-pybox)}]­[PF₆] (<b>1</b>) with methyl propynoate in acetonitrile yields the new complex <b>2</b> with complete selectivity. In the presence of NaCl, the reaction of <b>1</b> with propynoate esters in acetonitrile affords complexes <b>3a</b>,<b>b</b>. The addition of methanol to complex <b>3a</b> affords complex <b>4</b>, whose structure has been determined by X-ray diffraction analysis