Concurrent N-H, C-H Bond Activations

Some metal complexes can activate hydrocarbon C-H bonds intermolecularly and some can activate N-H bonds, but now chemists have discovered that a family of allyl nitrosyl complexes of tungsten can concurrently activate both the N-H and α-C-H bonds of pyrrolidine or piperidine (J. Am. Chem. Soc. 2006, 128, 14762). For example, when the complex shown (top) reacts with neat pyrrolidine at room temperature, the resulting complex (bottom) sports a pyrrolide ligand; the allyl ligand of the starting complex has become a vinylalkyl substituent of the new pyrrolide ligand. The hydrogen atoms on the pyrrolidine's nitrogen and α-carbon atoms are eliminated as H₂. Peter Legzdins of the University of British Columbia, Vancouver, whose group made the discovery, believes this type of transformation is unprecedented.