FeCl 2 -mediated Nucleophilic Chlorination of Iodoalkanes Accelerated by Phenanthroline Ligand

Alkyl halides have been considered not only important building blocks but also useful intermediates in synthetic methods of nucleophilic substitution, metal-halogen exchange, and cross-coupling reactions. As the practical synthesis of various alkyl halides, the halogen exchange is one of the fundamental and efficient reactions, which is mainly used for preparing alkyl bromides or iodides. Finkelstein-type reactions(1) have been well studied for the conversion of alkyl chlorides to the corresponding bromides or iodides and alkyl bromides to iodides, which reaction is an equilibrium shifted by taking advantage of the different solubility of the resulting sodium salt in acetone. However, the reverse processes, the replacement of iodide by bromide or chloride, or of bromide by chloride, were not simple.