Formation of 2-Substituted Iodobenzenes from Iodobenzene via Benzyne and Ate Complex Intermediates

The generation of benzyne from iodobenzene with lithium tetramethylpiperidide in THF at −40 °C in the presence of lithium amides and ester enolates leads to mixtures in which 2-substituted iodobenzenes are often the major products. These products are obtained by iodine transfer from iodobenzene to the intermediate 2-lithioaromatics. The transfer of iodine occurs via a hypervalent iodine (ate) complex.