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)­{κ3N,N,N-(S,S)-iPr-pybox)}]­[PF6] (1) with methyl propynoate in acetonitrile yields the new complex 2 with complete selectivity. In the presence of NaCl, the reaction of 1 with propynoate esters in acetonitrile affords complexes 3a,b. The addition of methanol to complex 3a affords complex 4, whose structure has been determined by X-ray diffraction analysis.