Electrochemically induced aromatic nucleophilic substitution in p-diiodobenzene with 5-C5H5)Fe(CO)2>- and 5-C5H5)W(CO)3>--anions

Article abstract of DOI:10.1016/0022-328X(94)05077-O

The reactions of p-diiodobenzene with <(η⁵-C5H5)Fe(CO)2>^- and <(η⁵-C5H5)W(CO)3>^- were studied using a complex of electrochemical techniques (cyclic voltammetry, rotating ring-disk electrode and preparative scale electrolysis).For <(η⁵-C5H5)Fe(CO)2>^- it was shown that aromatic nucleophilic substitution of either one or two iodine atoms in p-diiodobenzene for η⁵-cyclopentadienylirondicarbonyl can be performed through electrochemical activation of the aryl halide.The ratio of (η⁵-C5H5)Fe(CO)2C6H4I and (η⁵-C5H5)Fe(CO)2C6H4Fe(CO)2(η⁵-C5H5) was shown to depend strongly on the electrolysis conditions: electrode potential, electrolysis duration, etc.The yield of (η⁵-C5H5)Fe(CO)2C6H4Fe(CO)2(η⁵-C5H5) can be considerably increased when (η⁵-C5H5)Fe(CO)2C6H4I is taken as a starting compound.For <(η⁵-C5H5)W(CO)3I^- the main product of the reaction with p-diiodobenzene is (η⁵-C5H5)W(CO)3I. Keywords: Iron; Tungsten; Electrochemistry; Bond activation