Iridium PC_sp3P‑type Complexes with a Hemilabile Anisole Tether

A series of iridium PCsp3P complexes based on bis­(2-diisopropylphosphinophenyl)-2-anisoylmethane (PCanisHP) is reported. (PCanisP)­Ir­(H)Cl was generated from the C–H activation of the backbone by [Ir­(COD)­Cl]2 (COD = 1,5-cyclooctadiene), while the dihydride (PCanisP)­Ir­(H)2 was generated by hydride metathesis from (PCanisP)­Ir­(H)­Cl. Both complexes are 18e octahedral complexes and water stable. The hemilability of the anisole tether was probed using CO and PMe3; multiple isomers, in which the anisole substituent was displaced, were generated, showing the flexibility of the ligand backbone. (PCanisP)­Ir­(H)2 showed deuterium incorporation in the hydride, backbone, and anisole positions upon moderate heating in C6D6. Both (PCanisP)­Ir­(H)Cl and (PCanisP)­Ir­(H)2 were precatalysts for transfer dehydrogenation of cyclooctane under moderate conditions.