Barbier-type reactions iron salt catalysts

Much milder reaction conditions in the Barbier-type reaction can be employed by utilizing iron(III) salts as catalysts. For example, when 2 mol % FeCb is added to Smh, the Barbier reaction between a primary organic iodide and a ketone is complete within 3 h at room temperature (equation 19). The iron(III) is probably reduced by Smh to a low-valent species which serves as an efficient electron transfer catalyst, thus lowering the activation energy for the coupling process vide infra). 

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