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

Herein we explore the intrinsic organometallic reactivity of iron embedded in a tetradentate N3C macrocyclic 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 L-Me(H) and FeCl2, biaryl C-C coupling product formation through reaction with Griznard reagents, and cross-coupling reactions using L-Me(Br). or L-H(Br) in combination with Fe-0(CO)(5). Synthesis under light irradiation and moderate heating (50 degrees C) affords the aryl-Fe-II complexes [Fe-II(Br)(L-Me)(CO)] (1(Me)) and [Fe-II(L-H)(CO)(2)]Br (1(H)). Exhaustive spectroscopic characterization of these rare low-spin diamagnetic species, including their crystal structures, allowed the investigation of their intrinsic reactivity.

Automated summary

This study investigates the intrinsic organometallic reactivity of iron within a tetradentate N3C macrocyclic ligand scaffold, leading to the stabilization of aryl-Fe species crucial in Fe-catalyzed cross-coupling and C-H functionalization processes. The synthesis of aryl-Fe-II complexes under light irradiation and moderate heating allowed for thorough spectroscopic characterization and investigation of their intrinsic reactivity.