Single-electron transfer Grignard carbonyl additions

For the mechanism of the metal-mediated Grignard-type reactions in water, Li previously proposed a carbanion/allylmetal/radical triad, in which the specific mechanism of the reaction is dependent on the metal being used (Fig. 4.6). Recently, mechanistic studies of the aUylation detected secondary deuterium kinetic isotope effects in the metal-mediated aUylation ofbenzaldehyde in aqueous media.The inverse SDKIE observed for the indium and tin cases are consistent with the polar addition mechanism. For magnesium and antimony, normal SDKIE were observed. These were interpreted as single electron transfer processes on metal surface in the magnesium case, or between the allyhnetal and the carbonyl compound in the antimony case. 

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