Three iron complexes having bidentate 1-(2-aminophenyl)-substituted imidazol-2-ylidene ligands were synthesized by reactions of Cp∗FeN(SiMe3)2 (Cp∗: η5-C5Me5) with the corresponding imidazolium iodides. These iron complexes exhibited high catalytic performance for dehydrogenation of ammonia-borane in the presence of KN(SiMe3)2. The structure of an active species was determined by its NMR and high-resolution mass spectra and also by isolation of its CO adduct.