Facilitating Ferration of Aromatic Substrates Through Intramolecular Sodium Mediation.

Exploiting cooperative effects between Na and Fe(II) when present  in tris(amide) ferrate complexes, the chemoselective ferration of pentafluorobenzene, benzene, toluene, anisole and pyridine has been realised at room temperature. Demonstrating the importance of this bimetallic partnership neither the relevant sodium amide (NaHMDS or NaTMP) or the Fe(II) amide Fe(HMDS) 2  can efficiently metallate these substrates under the conditions of this study.  Combining NMR studies with isolation of key intermediates and DFT calculations we offer an account for how these reactions take place, uncovering a surprising reaction pathway in which metals cooperate in a synchronised manner. While isolated products are formally the result of Fe-H exchange, theoretical calculations indicate that the aromatic substrates undergo Na-H exchange followed by fast intramolecular transmetallation to Fe, thus stabilizing the newly generated aryl fragment.