Early Transition Metal-Catalyzed Hydroaminoalkylation

Hydroaminoalkylation was first reported for homoleptic early transition metal complexes by Clerici and Maspero in 1980. After these observations, hydroaminoalkylation was overlooked for decades due to low catalytic activity. A breakthrough by Herzon and Hartwig in 2007, using Ta(NMe2)5 as a catalyst, showed promising reactivity with N-alkylarylamines and unactivated alkenes. Since 2008, the Doye and Schafer groups and others have improved catalytic activity and expanded the substrate scope of early transition metal-catalyzed hydroaminoalkylation.