Amination of C-H bonds catalysed by ruthenium porphyrin complexes

The pharmaceuticl activities of organonitrogen compounds prompted the scientific community to develop new methods for C-N bond formation. In the last few years we have reported on the catalytic activity of porphyrin complexes in olefin aziridinations and hydrocarbon aminations employing arylazides as atom-efficient aminating agents. ArN3 generate a nitrene functionality "ArN" and the eco-friendly molecular nitrogen is the only side product. The insertion of "ArN" into a C-H bond of hydrocarbons yields benzylic imines, benzylic amines and allylic amines. To clarify the mechanism of the C-H amination reactions, the ruthenium bis-imido porphyirin complex (1) was fully characterized. The role of 1 in catalytic aminations was studied proving that 1 is an active reaction intermediate that shows a good balance between stability and reactivity. To the best of our knowledge, complex 1 is the first structurally characterised bis-imido porphyrin complex that shows a good catalytic activity in this class of reactions.