Isomerization of Internal Alkynes to Iridium(III) Allene Complexes via C-H Bond Activation: Expanded Substrate Scope, and Progress towards a Catalytic Methodology.

摘要: The synthesis of a series allene complexes (POCOP)Ir(η²-RC=(.)=CR') 1b-4b (POCOP = 2,6-bis(di-tert-butylphosphonito)benzene) via isomerization internal alkynes is reported. We have demonstrated that the application this methodology viable for wide variety alkyne substrates. Deuterium labeling experiments support our proposed mechanism. structures were determined using spectroscopic data analysis. Additionally, solid-state molecular structure complex 2b was single crystal X-ray diffraction studies and it confirmed assignment an iridium-bound product. rates measured NMR techniques over range temperatures to allow determination thermodynamic parameters. Finally, we report preliminary step towards developing catalytic methodology; may be liberated from metal center by exposure atmosphere carbon monoxide.