Catalytic homogeneous CH-activation reactions of cyclooctane with [Ir(cod)LL]X complexes (LL = N,N-chelating ligands, amines, phosphines; X = Cl, PF6)

A series of new [Ir(cod)LL]X complexes (LL = chelating ligands, amines, phosphines; X = Cl, PF6) was synthesized. The complexes catalyzed the selective homogeneous dehydrogenation of cyclooctane to give cyclooctene up to a rate of 61 turnovers. The activity and selectivity depends on the ligand structure of the corresponding coordination compound. The addition of external additives (amines and phosphines) increased the activities up to 100% in case of PCy3 and NHPh2. The dehydrogenation reaction showed a high temperature dependence.

Graphical abstract[Ir(cod)LL]X complexes (LL = chelating ligands, amines, phosphines; X = Cl, PF6) are able to catalyze the selective homogeneous dehydrogenation of cyclooctane to give cyclooctene. The activities and selectivities depend on the ligand structure of the corresponding coordination compound and the addition of external additives.Figure optionsDownload full-size imageDownload as PowerPoint slide