title: Ate Complexes in Iron-Catalyzed Cross-Coupling Reactions.
abstract: Iron-catalyzed cross-coupling reactions have an outstanding potential for sustainable organic synthesis, but remain poorly understood mechanistically. Here, we use electrospray-ionization (ESI) mass spectrometry to identify the ionic species formed in these reactions and characterize their reactivity. Transmetalation of Fe(acac)3(acac=acetylacetonato) with PhMgCl in THF (tetrahydrofuran) produces anionic iron ate complexes, whose nuclearity (1 to 4 Fe centers) and oxidation states (ranging from -I to +III) crucially depend on the presence of additives or ligands. Upon addition of iPrCl, formation of the heteroleptic FeIIIcomplex [Ph3Fe(iPr)]-is observed. Gas-phase fragmentation of this complex results in reductive elimination and release of the cross-coupling product with high selectivity.
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Parchomyk
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany. konrad.koszinowski@chemie.uni-goettingen.de.
authors.forename: Konrad
authors.initials: K
authors.lastname: Koszinowski
keywords: cross coupling; gas-phase reactions; iron; mass spectrometry; reaction mechanisms