NH-Heterocyclic Aryliodonium Salts and their Selective Conversion into N1-Aryl-5-iodoimidazoles

Abstract

<p> <span lang="EN-US" style="margin: 0px; color: rgb(0, 0, 170); font-family: &quot;Cambria&quot;,serif; font-size: 12pt;">The synthesis of N-arylimidazoles substituted at the sterically encumbered 5-position is a challenge for modern synthetic approaches. A new family of imidazolyl aryliodonium salts is reported, which serve as a stepping stone on the way to selective formation of N1-aryl-5-iodoimidazoles. Iodine acts as a &ldquo;universal&rdquo; placeholder poised for replacement by aryl substituents. These new &lambda;³-iodanes are produced by treating the NH-imidazole with ArI(OAc)₂, and are converted to N1-aryl-5-iodoimidazoles by a selective copper-catalyzed aryl migration. The method tolerates a variety of aryl fragments and is also applicable to substituted imidazoles.</span></p>