Organozinc compounds from alkyl halides

The synthesis of organozinc compounds by electrochemical processes from either low reactive halogenated substrates (alkyl chlorides) or pseudo-halogenated substrates (phenol derivatives, mesylates, triflates etc.) remains an important challenge. Indeed, as mentioned above, the use of electrolytic zinc prepared from the reduction of a metal halide or from zinc(II) ions does not appear to be a convenient method. However, recent work reported by Tokuda and coworkers would suggest that the electroreduction of a zinc(II) species in the presence of naphthalene leads to the formation of a very active zinc capable of reacting even with low reactive substrates (equation 23)11. 

Zinc. The salts used for the Zn reactions are the halides (chlorides, bromides and iodides) both alkyl and aryl compounds are used. Owing to the reactivity of organozinc compounds, air and moisture must be excluded from the reaction. Use of ether or dioxane, on evaporation of the solvent, leads to solvates RZnX-D (X = halide, D = Et20 or dioxane). The exchange between Et2Zn and Znl2 occurs slowly in ether at RT. 

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