Activating a Peroxo Ligand for C−O Bond Formation

Abstract

Dioxygen activation for effective C−O bond formation in the coordination sphere of a metal is a long standing challenge in chemistry for which the design of catalysts for oxygenations is slowed down by the complicated −sometimes poorly understood− mechanistic panorama. In this context, olefin-peroxide complexes could be valuable models for the study of such reactions. Herein, we showcase the isolation of rare 'Ir(cod)(peroxide)' complexes (cod =1,5-cyclooctadiene) from reactions with oxygen, and then the activation of the peroxide ligand for O−O bond cleavage and C−O bond formation by transfer of a hydrogen atom through PT/ET reactions to give 2-iradaoxetane complexes and water. 2,4, 1, and 1,cyclohexadiene were used as hydrogen atom donors. These reactions can be key steps in the oxy-functionalization of olefins with oxygen and they constitute a novel mechanistic pathway disclosed for iridium whose full reaction profile is supported by DFT-calculations.