Samarium diiodide alkyl halides

Samarium diiodide is a one electron reductant that is capable of reducing both alkyl halides and carbonyl compounds. The rate of the reduction depends on the nature of the substrate and the reaction conditions. The mechanism of the addition of alkyl halides to carbonyls was extensively studied. In case of the samarium Grignard processes, it was concluded that the reaction proceeds through an organosamarium intermediate. However, the mechanism of the samarium Barbier processes is not fully understood and there is no unambiguous evidence in favor of any of the possible pathways. 

Preparation. - The reaction of diphenylphosphinyl chloride with dicyclopentadienylsamarium (or samarium diiodide), followed by an alkyl halide (or alkyl tosylate, epoxide, or a,P-unsaturated ketone), provides a route to a... 

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