Iridium complex bearing a chiral hydroxy-amide functionalized N-heterocyclic carbene: a catalyst precursor for asymmetric transfer hydrogenation

A new monodentate iridium(III) complex bearing a readily accessible and tunable chiral hydroxy-amide functionalized N-heterocyclic carbene ligand, Cp∗Ir(NHC)Cl2, has been synthesized and characterized by crystallographic methods. The monodentate Cp∗Ir(NHC)Cl2 complex was found to act as a catalyst precursor for the stereoselective transfer hydrogenation of acetophenone in the presence of KOH even at room temperature. Moderate enantioselectivity was observed in the initial screening of the chiral ligands.

Graphical abstractA new monodentate iridium(III) complex bearing a readily accessible and tunable chiral hydroxy-amide functionalized N-heterocyclic carbene (NHC) ligand has been synthesized and characterized by crystallographic methods. The monodentate NHC–Ir complex acts as a catalyst precursor for the stereoselective transfer hydrogenation of acetophenone in the presence of KOH even at room temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide