Cross‐Coupling of Alkyl Halides with Aryl Grignard Reagents Catalyzed by a Low‐Valent Iron Complex

A striking reversal of the usual reactivity pattern of aryl Grignard reagents is observed for reactions in the presence of catalytic amounts of the “bare” ferrate complex [Li(tmeda)]2[Fe(C2H4)4] (1). Highly reduced iron–magnesium clusters may play a decisive role in the exceptionally facile and chemoselective cross-coupling reaction with alkyl halides (see scheme).