Unexpected Formation of (Dimethylaminomethylene)methylamide Complexes from the Reactions between Metal Chlorides and Lithium Dimethylamide

Reactions of MCl5 (M = Nb, Ta) with LiNMe2 have been found to yield M(NMe2)4(η2-MeNCH2NMe2) (M = Nb, 2a; Ta, 2b) containing a chelating ligand (dimethylaminomethylene)methylamide, as confirmed by NMR spectroscopy, DFT calculations, and their reactivity studies.