Two-Site O–H Addition to an Iridium Complex Featuring a Nonspectator Tricoordinate Phosphorus Ligand

Abstract

The synthesis and reactivity of an ambiphilic iridium complex IrCl(PPh₃)(<b>L1</b>) (<b>1</b>; <b>L1</b> = P(N(<i>o</i>-N(2-pyridyl)C₆H₄)₂)) featuring a chelating nontrigonal phosphorus triamide ligand is reported. The tandem Lewis basic Ir and Lewis acidic P of <b>1</b> achieve a two-site oxidative addition of phenol giving the iridaphenoxyphosphorane species IrHCl(PPh₃)(<b>L1</b>^OPh) (<b>3'</b>). In contrast, reactions of <b>1</b> with benzenethiol and benzeneselenol do not engage <b>L1</b> and instead proceed via metal-centered oxidative addition of the chalcogen-hydrogen bond. These findings establish metal-ligand cooperation involving nonspectator reactivity of tricoordinate phosphorus ligands.