Homogeneous Perdehydrogenation and Perhydrogenation of Fused Bicyclic N‑Heterocycles Catalyzed by Iridium Complexes Bearing a Functional Bipyridonate Ligand

Homogeneous perdehydrogenation of saturated bicyclic 2,6-dimethyl­deca­hydro-1,5-naph­thyridine and perhydrogenation of aromatic 2,6-dimethyl-1,5-naph­thyridine with release and uptake of five molecules of H₂ are efficiently achieved by iridium complexes bearing a functional bipyridonate ligand. Successive perhydrogenation and perdehydrogenation of 2,6-dimethyl-1,5-naph­thryridine using a single iridium complex also proceed with the reversible interconversion of the catalytic species, depending on the presence or absence of H₂.