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


  • Generous financial support from the Deutsche Forschungsgemeinschaft (Leibniz Award Program) and the Fonds der Chemischen Industrie is gratefully acknowledged. R.M. thanks the Alexander-von-Humboldt Foundation for a postdoctoral fellowship. We express our gratitude to Prof. K. Jonas, Mülheim, for valuable discussions and for providing a generous sample of the iron complex 1, as well as to Dr. A. Leitner for performing preliminary experiments.


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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).