936323-02-3Relevant articles and documents
Cyclometalation of primary benzyl amines by Ruthenium(II), Rhodium(III), and Iridium(III) complexes
Sortais, Jean-Baptiste,Pannetier, Nicolas,Holuigue, Alexandre,Barloy, Laurent,Sirlin, Claude,Pfeffer, Michel,Kyritsakas, Nathalie
, p. 1856 - 1867 (2007)
The cyclometalation of chiral and achiral primary amines occurred readily with Ru(II), Rh(III), and Ir(III) derivatives. Thus, the metalation of (R)-1-phenylethylamine by [(η6-benzene)RuCl2] 2, [(η5-Cp*)-RhCl2]2 and [(η5-Cp*)IrCl2]2 was studied. Good yields of the expected cationic products in which the phenyl group was ortho-metalated were obtained for the rhodium and the ruthenium derivatives, whereas a mixture of products was formed in the case of the iridium complex. Benzylamine, (R)-1-phenylpropylamine, (R)-1-(1-naphthyl)ethylamine, and (R)-1-aminotetraline afforded also the cycloruthenation products whose general formula is [(η6-benzene)Ru(N-C)(NCMe)]PF6 where N-C represents the orthometalated ligands. Substitution of the acetonitrile ligand by PMe2Ph occurred readily on the ruthenium complexes, affording stable compounds that were characterized by X-ray diffraction studies on single crystals, thus ascertaining the existence of the cycloruthenated five-membered rings. Accurate analyses of the structure of the complexes were implemented in solution and in the solid state. The (S) configuration at the metal was usually associated with a δ conformation of the metallacycle, and conversely, the (R) configuration with the λ conformation. The study of the conformation of the five-membered rings revealed that the orientation of the NH2 group is such that one NH unit is oriented toward the η6-benzene ring (roughly parallel to the Ru-centroid benzene vector), whereas the second NH is parallel to the Ru-L bond, L = NCMe or PMe2Ph.
