Unprecedented diastereoselective generation of chiral-at-metal, half sandwich Ir(III) and Rh(III) complexes via anomeric isomerism on "sugar-coated" N-heterocyclic carbene ligands.

The first example of the diastereoselective synthesis induced by anomeric isomerism of sugar units in ligands of metal complexes was demonstrated. S and R configurations of chiral-at-metal Ir(III) and Rh(III) complexes were selectively obtained by using chelate-type NHC ligands with α- and β-glucopyranosyl units, respectively.