Direct C–H iodination of 1,3-azoles catalysed by CuBr2

Abstract A mild method was developed for the direct C–H iodination of 1,3-azoles catalysed by CuBr 2 . Compared with the traditional metalation/iodination sequences carried out with n BuLi or TMPLi (TMP = 2,2,6,6-tetramethylpiperidino), a relatively weaker base, LiO t Bu, was used in the presence of 1,10-phenanthroline. Five series of 1,3-azoles, including benzoxazole, benzothiozole, N -methyl-benzoimidazole, 5-phenyloxazole and 2-phenyl-1,3,4-oxadiazole were tested and afforded the corresponding iodination products.