Employing TosMIC as a C1N1 “Two-Atom Synthon” in Imidazole Synthesis by Neighboring Group Assistance Strategy

We report an I2/FeCl3-co-promoted formal [2 + 2+1] annulation of aryl methyl ketones, 2-aminobenzyl alcohols, and p-toluenesulfonylmethyl isocyanide (TosMIC) by neighboring group (−CH2OH) assistance. This is a novel example of using the Van Leusen reagent as a unique C1N1 “two-atom synthon” in the synthesis of imidazoles. Preliminary mechanism studies showed that TsCH2NH2 might be the key intermediate in this reaction. Furthermore, this reaction not only unlocks a novel strategy for imidazole synthesis, but also exploits a new reactivity of TosMIC.