Use of Niobium(III) and Niobium(V) Compounds in Catalytic Imine Metathesis under Mild Conditions

The niobium reagents NbCl3(DME) (1) and mer-(DME)Cl3NbNPh (6) serve as effective catalysts or precatalysts in imine metathesis reactions with a variety of aldimines. These reactions are particularly convenient because they proceed at room temperature in a period of hours; noteworthy is the fact that 1 functions as a precatalyst even though it does not contain an imide ligand.