Efficient Dehydrogenation of Amines and Carbonyl Compounds Catalyzed by a Tetranuclear Ruthenium-mu-Oxo-mu-Hydroxo-Hydride Complex.

The tetranuclear ruthenium-mu-oxo-mu-hydroxo-hydride complex {[(PCy(3))(CO)RuH](4)(mu(4)-O)(mu(3)-OH)(mu(2)-OH)} (1) was found to be a highly effective catalyst for the transfer dehydrogenation of amines and carbonyl compounds. For example, the initial turnover rate of the dehydrogenation of 2-methylindoline was measured to be 1.9 s(-1) with the TON of 7950 after 1 h at 200 degrees C. The extensive H/D scrambling patterns observed from the dehydrogenation reaction of indoline-N-d(1) and indoline-alpha-d(2) suggest a monohydride mechanistic pathway with the C-H bond activation rate-limiting step.