Divergent Fe-Mediated C-H Activation Paths Driven by Alkali Cations.

The association of the ferrous complex FeCl(dmpe) () with alkali bases M(hmds) (M = Li, Na, K) proves to be an efficient platform for the activation of Ar-H bonds. Two mechanisms can be observed, leading to either Ar-Fe species by deprotonative ferration or hydrido species Ar-Fe-H by oxidative addition of transient Fe(dmpe) generated by reduction of . Importantly, the nature of the alkali cation in M(hmds) has a strong influence on the preferred path.

The crucial and multifaceted roles of main-group cations and their salts in iron-mediated cross-couplings.

While a broad variety of iron-catalyzed cross-couplings involve the use of main-group organometallics R-[M] as nucleophiles, the role of the [M] cation in the coupling process is generally disregarded. However, several beneficial effects of [M] cations by themselves or involved in ionic salts used as additives have been observed in such procedures. At the molecular level, interaction of those [M] cations with on-cycle organoiron intermediates can proceed in several ways.