Aldehyde Binding through Reversible C-C Coupling with the Pincer Ligand upon Alcohol Dehydrogenation by a PNP-Ruthenium Catalyst

Primary alcohol dehydrogenation by a PNP-Ru(II) catalyst was probed by low-temperature NMR experiments. Facile dehydrogenation occurred at -30 degrees C, but the resulting aldehydes were not found in solution, as they were trapped by the catalyst through a new mode of metal-ligand cooperation involving Ru-O coordination and an unusual, highly reversible C-C coupling with the PNP pincer ligand.