Well-Defined Aryl-FeII Complexes in Cross-Coupling and C-H Activation Processes

Abstract

Herein we explore the intrinsic organometallic reactivity of iron embedded in a tetradentate N3C macrocy-clic ligand scaffold that allows the stabilization of aryl-Fe species, which are key intermediates in Fe-catalyzed cross-coupling and C-H functionalization processes. This study covers C-H activation reactions using MeLH and FeCl2, biaryl C-C coupling product formation through reaction with Gri-gnard reagents, and cross-coupling reactions using MeLBr or HLBr in combination with Fe0(CO)5. Synthesis under light irradiation and moderate heating (50 ºC) affords aryl-FeII complexes [FeII(Br)(MeL)(CO)] (1Me) and [FeII(HL)(CO)2]Br (1H). Exhaustive spectroscopic characterization of these rare low spin diamagnetic species, including their crystal struc-tures, allowed the investigation of their intrinsic reactivity