(Chemical Equation Presented) Iron at the crossroads: A remarkable mechanistic dichotomy in iron-catalyzed allylic substition increases not only the scope of regioselective allylic alkylation but could also herald the development of asymmetric allylic substitution (see Scheme, MTBE = methyl tert-butyl ether). Depending on the ligand used, either a σ-or a π-allyl mechanism is observed.