Transfer Hydrogenation Catalysis by a N‐Heterocyclic Carbene Iridium Complex on a Polyoxometalate Platform

Abstract A divacant Keggin polyanion has been decorated with a N‐heterocyclic carbene (NHC) iridium(I) organometallic complex to provide a molecular model of an Ir‐based supported catalyst. The characterization of the hybrid compound has been performed by multinuclear NMR spectroscopy, infrared spectroscopy, cyclic voltammetry, and mass spectroscopy, and the results are in agreement with a bisfunctionalization of the polyoxometalate scaffold. The resulting supported homogeneous complex has been successfully used to catalyze the transfer hydrogenation from iPrOH to benzophenone [with a turnover number (TON) of 680 and a turnover frequency (TOF) of up to 540 h–1].