Asymmetric hydrogenation of quinazolinium salts catalysed by halide-bridged dinuclear iridium complexes bearing chiral diphosphine ligands.

Asymmetric hydrogenation of quinazolinium salts was catalysed by halogen-bridged dinuclear iridium complexes bearing chiral diphosphine ligands, yielding tetrahydroquinazoline and 3,4-dihydroquinazoline with high enantioselectivity. A derivative of chiral dihydroquinazoline was used as a chiral NHC ligand.