Synthesis of 2-Iodoazulenes by the Iododeboronation of Azulen-2-ylboronic Acid Pinacol Esters with Copper(I) Iodide
Azulen-2-ylboronic acid pinacol ester, prepared by iridium-catalyzed C-H borylation of azulene, efficiently underwent iododeboronation with a stoichiometric amount of copper(I) iodide. This reaction allowed the synthesis of 2-iodoazulene in only two steps starting from azulene. This methodology was successfully applied to analogous azulenes.
Synthesis of 2-aminoazulene derivatives. Nucleophilic and palladium-catalyzed amination of 2-substituted azulene
Amination of 2-substituted azulene was carefully examined using several types of amines, and the scope and limitation of substrates and reagents in these direct nucleophilic aminations were found. The synthesis of 2-aminoazulenes was successfully achieved by the reaction of 2-bromoazulene with several amines via palladium-catalyzed amination.