Reactions of acyl anions generated from acid chlorides and diiodosamarium

Acid chlorides react with SmI₂ to give α-diketones. Various experiments show that the initially formed acyl radical is rapidly transformed into an acyl anion which is thus generated by quite an unusual route.This species acylates acid chlorides, aldehydes and ketones in situ to give α-diketones and α-ketols. There are some limitations to this acyl anion chemistry but the reactions are realized with a good efficiency at room temperature in THF solution.